make repair_tool less op

bin/app/data/config/buildings.toml

@@ -82,6 +82,6 @@ cost = 25
 player_placeable = true
 construction_time_seconds = 1
 surface_mask = [
-  "SAA",
-  "SAA>",
+  "<AAS",
+  " AAS",
 ]

bin/app/data/config/modules.toml

@@ -1,26 +1,29 @@
 # modules.toml
 #
-# First real-content iteration: module ids and surface masks are the designed
-# content; stats, materials, and threat costs are placeholders until the
-# recipe and balancing passes.
+# Production tree v2: all weapons are railguns for now — the implementation
+# (instant damage, no projectile, no ammunition) stays as-is and the beam
+# visual reads as a tracer round. Lasers are reserved for a future distinct
+# weapon type (see docs/content_design.md, "Production tree v2 — Weapons").
+# Combat stats are placeholders until the arena balancing pass;
+# production_time_seconds values come from the numbers pass.
 #
 # Unlock progression is mostly disabled (unlock_at_station_level = -1) pending
-# the balancing pass. The laser cannons are the exception: laser_cannon_m is
-# gated to station level 1, and laser_cannon_l requires laser_cannon_m to be
-# unlocked first (unlock_requires) — a demonstration of the prerequisite chain.
+# the pacing pass. The railguns are the exception: railgun_m is gated to
+# station level 1, and railgun_l requires railgun_m to be unlocked first
+# (unlock_requires) — a demonstration of the prerequisite chain.
 #
 # Surface mask footprint ladder — footprints gate which hulls can mount a
 # module, purely through geometry (see ships.toml for the matching hull
 # grids):
 #
-#   1x1       laser_cannon_s, salvager, repair_tool   fits every hull, incl. drones
+#   1x1       railgun_s, salvager, repair_tool        fits every hull, incl. drones
 #   1x2       maneuvering_thrusters, sensor_booster,
 #             armor_plates                            frigate and up
 #   1x3       afterburner                             frigate and up (eats most of a frigate)
 #   L-shape   weapon_stabilizer, weapon_primer,
 #             weapon_upgrade                          frigate and up
-#   2x2       laser_cannon_m, drone_bay               cruiser and up (no 2x2 area on s hulls)
-#   3x3       laser_cannon_l                          battleship and up (no 3x3 area on m hulls)
+#   2x2       railgun_m, drone_bay                    cruiser and up (no 2x2 area on s hulls)
+#   3x3       railgun_l                               battleship and up (no 3x3 area on m hulls)
 #   2x6       drone_hangar                            carrier only
 
 # -----------------------------------------------------------------------------
@@ -28,13 +31,13 @@
 # -----------------------------------------------------------------------------
 
 [[module]]
-id = "laser_cannon_s"
+id = "railgun_s"
 unlock_at_station_level = -1
 surface_mask = ["O"]
-materials = [{item = "laser_cannon_s_module", amount = 1}]
-production_time_seconds = 0.5
+materials = [{item = "railgun_s_module", amount = 1}]
+production_time_seconds = 1
 fill_color = "#FF8040"
-glyph = "Ls"
+glyph = "Rs"
 
 [module.weapon]
 damage = 2
@@ -43,37 +46,37 @@ attack_rate_hz = 2.0
 
 
 [[module]]
-id = "laser_cannon_m"
-unlock_at_station_level = 1
+id = "railgun_m"
+unlock_at_station_level = 2
 surface_mask = [
     "OO",
     "OO"]
-materials = [{item = "laser_cannon_m_module", amount = 1}]
-production_time_seconds = 2
+materials = [{item = "railgun_m_module", amount = 1}]
+production_time_seconds = 3
 fill_color = "#FF8040"
-glyph = "Lm"
+glyph = "Rm"
 
 [module.weapon]
-damage = 10
+damage = 14
 attack_range_m = 70
 attack_rate_hz = 1.5
 
 
 [[module]]
-id = "laser_cannon_l"
-unlock_at_station_level = 1
-unlock_requires = ["laser_cannon_m"]
+id = "railgun_l"
+unlock_at_station_level = 6
+unlock_requires = ["railgun_m"]
 surface_mask = [
     "OOO",
     "OOO",
     "OOO"]
-materials = [{item = "laser_cannon_l_module", amount = 1}]
-production_time_seconds = 8
+materials = [{item = "railgun_l_module", amount = 1}]
+production_time_seconds = 4
 fill_color = "#FF8040"
-glyph = "Ll"
+glyph = "Rl"
 
 [module.weapon]
-damage = 40
+damage = 52
 attack_range_m = 100
 attack_rate_hz = 0.8
 
@@ -86,28 +89,28 @@ id = "salvager"
 unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "salvager_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#AACC44"
 glyph = "Sv"
 
 [module.salvage]
-collection_range_m = 500
-cargo_capacity = 10
+collection_range_m = 60
+cargo_capacity = 20
 collection_rate_hz = 0.5
 
 
 [[module]]
 id = "repair_tool"
-unlock_at_station_level = -1
+unlock_at_station_level = 0
 surface_mask = ["O"]
 materials = [{item = "repair_tool_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#66CCFF"
 glyph = "Rp"
 
 [module.repair]
 repair_rate_hz = 1
-repair_amount_hp = 6
+repair_amount_hp = 4
 repair_range_m = 80
 
 # -----------------------------------------------------------------------------
@@ -116,10 +119,10 @@ repair_range_m = 80
 
 [[module]]
 id = "afterburner"
-unlock_at_station_level = -1
+unlock_at_station_level = 2
 surface_mask = ["OOO"]
 materials = [{item = "afterburner_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#40A0FF"
 glyph = "Ab"
 
@@ -130,10 +133,10 @@ added_main_acceleration_mpss = 60
 
 [[module]]
 id = "maneuvering_thrusters"
-unlock_at_station_level = -1
+unlock_at_station_level = 1
 surface_mask = ["OO"]
 materials = [{item = "maneuvering_thrusters_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#40A0FF"
 glyph = "Mt"
 
@@ -147,23 +150,23 @@ added_maneuvering_acceleration_mpss = 10
 
 [[module]]
 id = "armor_plates"
-unlock_at_station_level = -1
+unlock_at_station_level = 0
 surface_mask = ["OO"]
 materials = [{item = "armor_plates_module", amount = 1}]
-production_time_seconds = 3
+production_time_seconds = 1
 fill_color = "#808080"
 glyph = "A"
 
 [module.health]
-added_hp = 40
+added_hp = 1200
 
 
 [[module]]
 id = "sensor_booster"
-unlock_at_station_level = -1
+unlock_at_station_level = 1
 surface_mask = ["OO"]
 materials = [{item = "sensor_booster_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#40A0FF"
 glyph = "S"
 
@@ -176,13 +179,13 @@ added_sensor_range_m = 50
 
 [[module]]
 id = "weapon_upgrade"
-unlock_at_station_level = -1
+unlock_at_station_level = 4
 surface_mask = [
     "OO",
     "OX",
 ]
 materials = [{item = "weapon_upgrade_module", amount = 1}]
-production_time_seconds = 4
+production_time_seconds = 2
 fill_color = "#FF4040"
 glyph = "Wu"
 
@@ -192,13 +195,13 @@ multiplied_damage = 1.2
 
 [[module]]
 id = "weapon_primer"
-unlock_at_station_level = -1
+unlock_at_station_level = 4
 surface_mask = [
     "OO",
     "OX",
 ]
 materials = [{item = "weapon_primer_module", amount = 1}]
-production_time_seconds = 4
+production_time_seconds = 2
 fill_color = "#FF4040"
 glyph = "Wp"
 
@@ -208,18 +211,18 @@ multiplied_attack_rate_hz = 1.2
 
 [[module]]
 id = "weapon_stabilizer"
-unlock_at_station_level = -1
+unlock_at_station_level = 3
 surface_mask = [
     "OO",
     "OX",
 ]
 materials = [{item = "weapon_stabilizer_module", amount = 1}]
-production_time_seconds = 4
+production_time_seconds = 1
 fill_color = "#FF4040"
 glyph = "Ws"
 
 [module.weapon]
-multiplied_attack_range_m = 1.5
+multiplied_attack_range_m = 1.3
 multiplied_attack_rate_hz = 0.8
 
 # -----------------------------------------------------------------------------
@@ -231,23 +234,23 @@ multiplied_attack_rate_hz = 0.8
 
 [[module]]
 id = "drone_bay"
-unlock_at_station_level = -1
+unlock_at_station_level = 5
 surface_mask = [
     "OO",
     "OO"]
 materials = [{item = "drone_bay_module", amount = 1}]
-production_time_seconds = 5
+production_time_seconds = 3
 fill_color = "#CC66FF"
 glyph = "Db"
 
 
 [[module]]
 id = "drone_hangar"
-unlock_at_station_level = -1
+unlock_at_station_level = 9
 surface_mask = [
     "OOOOOO",
     "OOOOOO"]
 materials = [{item = "drone_hangar_module", amount = 1}]
-production_time_seconds = 20
+production_time_seconds = 6
 fill_color = "#9933CC"
 glyph = "Dh"

bin/app/data/config/recipes.toml

@@ -1,26 +1,26 @@
 # recipes.toml
 #
-# First real-content iteration of the production tree. Quantities and
-# durations are a first guess; the balancing pass will tune them and assign
-# real unlock_at_station_level values. Almost everything is unlocked for now so
-# the full tree is testable; the only gated recipe schematics are the medium and
-# large laser-cannon item recipes, which demonstrate the unlock_requires
-# prerequisite chain (large requires medium — see modules.toml / ships.toml).
+# Production tree v2 (structure in docs/content_design.md, numbers with
+# derivations in docs/balancing/derived.md). Quantities and durations are tuned so that every
+# fitted ship lands on the threat-cost ladder and the ratio curve is
+# realized: tier 1 ratios are 1:1, tier 2 ratios are 2:3, tier 3+ ratios
+# are deliberately strange.
 #
-# Input chain per game phase — each phase adds exactly one new base input:
+# Input chain per game phase — each phase transition adds exactly one new
+# base input:
 #
-#   early  iron_ore + copper_ore   -> ingots -> copper_wire, steel_plate,
-#                                    circuit_board
-#   mid    + titanium_ore          -> titanium_frame; assembler-made
-#                                    mechanical_parts, targeting_unit,
-#                                    drive_unit
-#   late   + advanced_alloy        -> reinforced_plating, capital_core.
-#                                    advanced_alloy CANNOT be mined; it only
-#                                    comes from reprocessing salvaged scrap,
-#                                    so capital production requires combat.
+#   early  iron_ore + copper_ore    minable on every asteroid tile (the
+#                                   asteroid is an M-type body — its bulk
+#                                   rock IS ore)
+#   mid    + quartz                 geode deposits in expansion territory
+#                                   (deposit gating pending — see action
+#                                   item 5 in docs/balancing/README.md;
+#                                   until then quartz mines anywhere)
+#   late   + voidsteel              battle-forged: ONLY from reprocessing
+#                                   salvaged scrap, so capital production
+#                                   requires combat
 #
-# Run tools/verify_recipes.py after editing to check that every consumed
-# item has a producer and every item has a visuals.toml entry.
+# Run tools/verify_recipes.py and tools/threat_report.py after editing.
 
 # -----------------------------------------------------------------------------
 # Mining (tier 0)
@@ -38,405 +38,409 @@ id = "mine_copper_ore"
 building = "miner"
 inputs = []
 outputs = [{item = "copper_ore", amount = 1}]
-duration_seconds = 1.5
+duration_seconds = 1.0
 
-# Titanium is the midgame ore: mined three times slower than iron.
 [[recipe]]
-id = "mine_titanium_ore"
+id = "mine_quartz"
 building = "miner"
 inputs = []
-outputs = [{item = "titanium_ore", amount = 1}]
-duration_seconds = 3.0
+outputs = [{item = "quartz", amount = 1}]
+duration_seconds = 2.0
 
 # -----------------------------------------------------------------------------
-# Smelting (tier 1)
+# Smelting (tier 1) — one recipe per input item; ratios are 1:1 with miners.
 # -----------------------------------------------------------------------------
 
 [[recipe]]
 id = "iron_ingot"
 building = "smelter"
-inputs = [{item = "iron_ore", amount = 2}]
+inputs = [{item = "iron_ore", amount = 1}]
 outputs = [{item = "iron_ingot", amount = 1}]
-duration_seconds = 2.0
+duration_seconds = 1.0
 
 [[recipe]]
 id = "copper_ingot"
 building = "smelter"
-inputs = [{item = "copper_ore", amount = 2}]
+inputs = [{item = "copper_ore", amount = 1}]
 outputs = [{item = "copper_ingot", amount = 1}]
-duration_seconds = 2.5
+duration_seconds = 1.0
 
 [[recipe]]
-id = "titanium_ingot"
+id = "silicon"
 building = "smelter"
-inputs = [{item = "titanium_ore", amount = 3}]
-outputs = [{item = "titanium_ingot", amount = 1}]
-duration_seconds = 4.0
+inputs = [{item = "quartz", amount = 1}]
+outputs = [{item = "silicon", amount = 1}]
+duration_seconds = 2.0
+
+# Scrap smelting: the safe, boring sink. Deliberately value-losing (4 threat
+# of scrap becomes a 2-threat ingot) — reprocessing is the value-preserving
+# path.
+[[recipe]]
+id = "scrap_smelting"
+building = "smelter"
+inputs = [{item = "scrap", amount = 1}]
+outputs = [{item = "iron_ingot", amount = 1}]
+duration_seconds = 1.0
 
 # -----------------------------------------------------------------------------
-# Reprocessing
-#
-# The only source of advanced_alloy: salvaged scrap from destroyed ships.
+# Reprocessing — the only source of voidsteel (battle-forged; formed when
+# weapon plasma anneals hull metal in the violence of ship destruction).
+# Weights are authored for the fully unlocked pool state; the pool
+# renormalizes over implicitly unlocked items early game.
 # -----------------------------------------------------------------------------
 
 [[recipe]]
 id = "reprocessing_cycle"
 building = "reprocessing_plant"
-inputs = [{item = "scrap", amount = 5}]
-duration_seconds = 3.0
+inputs = [{item = "scrap", amount = 4}]
+duration_seconds = 4.0
 
   [[recipe.outputs]]
   item = "iron_ingot"
-  amount = 2
-  probability = 0.45
+  amount = 1
+  probability = 0.3
 
   [[recipe.outputs]]
   item = "copper_ingot"
   amount = 1
-  probability = 0.25
+  probability = 0.3
 
   [[recipe.outputs]]
-  item = "titanium_ingot"
+  item = "silicon"
   amount = 1
-  probability = 0.15
+  probability = 0.2
 
   [[recipe.outputs]]
-  item = "advanced_alloy"
+  item = "voidsteel"
   amount = 1
-  probability = 0.15
+  probability = 0.2
 
 # -----------------------------------------------------------------------------
-# Basic components (tier 2, early game)
+# Tier 2 — early intermediates (clean ratios, ~2:3)
 # -----------------------------------------------------------------------------
 
-[[recipe]]
-id = "copper_wire"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "copper_ingot", amount = 1}]
-outputs = [{item = "copper_wire", amount = 2}]
-duration_seconds = 1.5
-
 [[recipe]]
 id = "steel_plate"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [{item = "iron_ingot", amount = 2}]
 outputs = [{item = "steel_plate", amount = 1}]
+duration_seconds = 3.0
+
+[[recipe]]
+id = "copper_wire"
+building = "assembler"
+inputs = [{item = "copper_ingot", amount = 1}]
+outputs = [{item = "copper_wire", amount = 2}]
+duration_seconds = 1.0
+
+[[recipe]]
+id = "copper_coil"
+building = "assembler"
+inputs = [{item = "copper_wire", amount = 2}]
+outputs = [{item = "copper_coil", amount = 1}]
+duration_seconds = 1.5
+
+# Depth-3 chain (ore -> ingot -> plate -> block) is the factory's
+# doubling-time knob; see the block economy rules in docs/balancing/rules.md.
+# Explicitly unlocked at start (-1): building blocks appear in no
+# schematic's materials, so implicit unlocking can never reach this recipe.
+[[recipe]]
+id = "building_block"
+unlock_at_station_level = -1
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 2}]
+outputs = [{item = "building_block", amount = 4}]
+duration_seconds = 2.0
+
+# -----------------------------------------------------------------------------
+# Tier 3 — mid intermediates (strange ratios begin; need quartz)
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "control_chip"
+building = "assembler"
+inputs = [{item = "silicon", amount = 1}, {item = "copper_wire", amount = 2}]
+outputs = [{item = "control_chip", amount = 1}]
+duration_seconds = 5.0
+
+[[recipe]]
+id = "capacitor_bank"
+building = "assembler"
+inputs = [{item = "copper_coil", amount = 2}, {item = "silicon", amount = 1}]
+outputs = [{item = "capacitor_bank", amount = 1}]
+duration_seconds = 5.0
+
+# The quality gate for m+ hulls: a deliberately long-running recipe
+# (time-heavy archetype).
+[[recipe]]
+id = "hardened_steel"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 3}]
+outputs = [{item = "hardened_steel", amount = 1}]
+duration_seconds = 12.0
+
+[[recipe]]
+id = "ceramic_plate"
+building = "assembler"
+inputs = [{item = "quartz", amount = 2}]
+outputs = [{item = "ceramic_plate", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "drive_unit"
+building = "assembler"
+inputs = [
+    {item = "steel_plate", amount = 2},
+    {item = "copper_coil", amount = 2},
+    {item = "control_chip", amount = 1},
+]
+outputs = [{item = "drive_unit", amount = 1}]
+duration_seconds = 8.0
+
+# -----------------------------------------------------------------------------
+# Tier 4 — late intermediates (need voidsteel)
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "voidsteel_plate"
+building = "assembler"
+inputs = [{item = "voidsteel", amount = 1}, {item = "hardened_steel", amount = 1}]
+outputs = [{item = "voidsteel_plate", amount = 1}]
+duration_seconds = 8.0
+
+[[recipe]]
+id = "capital_core"
+building = "assembler"
+inputs = [
+    {item = "voidsteel", amount = 2},
+    {item = "capacitor_bank", amount = 1},
+    {item = "control_chip", amount = 1},
+]
+outputs = [{item = "capital_core", amount = 1}]
+duration_seconds = 10.0
+
+# -----------------------------------------------------------------------------
+# Shortcut recipes — drop-only assembler recipe schematics
+# (unlock_at_station_level >= 0). Pure rewards: item threat stays defined by
+# the base (expensive) path via the max rule, so shortcuts give real factory
+# efficiency without shifting any balance.
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "shortcut_steel_plate"
+unlock_at_station_level = 1
+building = "assembler"
+inputs = [{item = "iron_ore", amount = 3}]
+outputs = [{item = "steel_plate", amount = 1}]
 duration_seconds = 2.0
 
 [[recipe]]
-id = "circuit_board"
-unlock_at_station_level = -1
+id = "shortcut_control_chip"
+unlock_at_station_level = 2
 building = "assembler"
-inputs = [{item = "iron_ingot", amount = 1}, {item = "copper_wire", amount = 2}]
-outputs = [{item = "circuit_board", amount = 1}]
-duration_seconds = 2.0
+inputs = [{item = "quartz", amount = 2}]
+outputs = [{item = "control_chip", amount = 1}]
+duration_seconds = 4.0
 
 [[recipe]]
-id = "building_blocks"
-unlock_at_station_level = -1
+id = "shortcut_hardened_steel"
+unlock_at_station_level = 2
 building = "assembler"
 inputs = [{item = "iron_ingot", amount = 4}]
-outputs = [{item = "building_block", amount = 10}]
-duration_seconds = 4.0
-
-# -----------------------------------------------------------------------------
-# Advanced components (tier 3, midgame)
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "mechanical_parts"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 1}, {item = "iron_ingot", amount = 1}]
-outputs = [{item = "mechanical_parts", amount = 2}]
-duration_seconds = 2.5
-
-[[recipe]]
-id = "targeting_unit"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "circuit_board", amount = 2}, {item = "copper_wire", amount = 1}]
-outputs = [{item = "targeting_unit", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "drive_unit"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "steel_plate", amount = 1},
-    {item = "mechanical_parts", amount = 1},
-    {item = "circuit_board", amount = 1},
-]
-outputs = [{item = "drive_unit", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "titanium_frame"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "titanium_ingot", amount = 2}, {item = "steel_plate", amount = 1}]
-outputs = [{item = "titanium_frame", amount = 1}]
-duration_seconds = 4.0
-
-# -----------------------------------------------------------------------------
-# Capital components (tier 4, lategame — gated on advanced_alloy)
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "reinforced_plating"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 2}, {item = "advanced_alloy", amount = 1}]
-outputs = [{item = "reinforced_plating", amount = 1}]
-duration_seconds = 5.0
-
-[[recipe]]
-id = "capital_core"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "targeting_unit", amount = 1},
-    {item = "drive_unit", amount = 1},
-    {item = "advanced_alloy", amount = 2},
-]
-outputs = [{item = "capital_core", amount = 1}]
+outputs = [{item = "hardened_steel", amount = 1}]
 duration_seconds = 8.0
 
-# -----------------------------------------------------------------------------
-# Module items — early game
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "laser_cannon_s_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "iron_ingot", amount = 2}, {item = "circuit_board", amount = 1}]
-outputs = [{item = "laser_cannon_s_module", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "salvager_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 1}, {item = "circuit_board", amount = 1}]
-outputs = [{item = "salvager_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "repair_tool_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "circuit_board", amount = 2}, {item = "copper_wire", amount = 1}]
-outputs = [{item = "repair_tool_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "armor_plates_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 2}]
-outputs = [{item = "armor_plates_module", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "sensor_booster_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "circuit_board", amount = 1}, {item = "copper_wire", amount = 2}]
-outputs = [{item = "sensor_booster_module", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "maneuvering_thrusters_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "mechanical_parts", amount = 1}, {item = "copper_wire", amount = 1}]
-outputs = [{item = "maneuvering_thrusters_module", amount = 1}]
-duration_seconds = 3.0
-
-# -----------------------------------------------------------------------------
-# Module items — midgame
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "afterburner_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "drive_unit", amount = 1}, {item = "steel_plate", amount = 1}]
-outputs = [{item = "afterburner_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "weapon_upgrade_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "steel_plate", amount = 1}]
-outputs = [{item = "weapon_upgrade_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "weapon_primer_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "copper_wire", amount = 2}]
-outputs = [{item = "weapon_primer_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "weapon_stabilizer_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "mechanical_parts", amount = 1}]
-outputs = [{item = "weapon_stabilizer_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "laser_cannon_m_module"
-unlock_at_station_level = 1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "titanium_frame", amount = 1}]
-outputs = [{item = "laser_cannon_m_module", amount = 1}]
-duration_seconds = 6.0
-
-[[recipe]]
-id = "drone_bay_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "titanium_frame", amount = 1},
-    {item = "mechanical_parts", amount = 1},
-    {item = "circuit_board", amount = 1},
-]
-outputs = [{item = "drone_bay_module", amount = 1}]
-duration_seconds = 6.0
-
-# -----------------------------------------------------------------------------
-# Module items — lategame
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "laser_cannon_l_module"
-unlock_at_station_level = 1
-unlock_requires = ["laser_cannon_m_module"]
-building = "assembler"
-inputs = [
-    {item = "targeting_unit", amount = 2},
-    {item = "reinforced_plating", amount = 2},
-    {item = "titanium_frame", amount = 1},
-]
-outputs = [{item = "laser_cannon_l_module", amount = 1}]
-duration_seconds = 12.0
-
-[[recipe]]
-id = "drone_hangar_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "capital_core", amount = 1},
-    {item = "titanium_frame", amount = 2},
-    {item = "reinforced_plating", amount = 2},
-]
-outputs = [{item = "drone_hangar_module", amount = 1}]
-duration_seconds = 20.0
-
 # -----------------------------------------------------------------------------
 # Ship hulls
 # -----------------------------------------------------------------------------
 
 [[recipe]]
 id = "drone_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [{item = "iron_ingot", amount = 5}, {item = "circuit_board", amount = 1}]
+inputs = [{item = "iron_ingot", amount = 1}]
 outputs = [{item = "drone_hull", amount = 1}]
-duration_seconds = 4.0
+duration_seconds = 1.0
 
 [[recipe]]
 id = "frigate_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [
-    {item = "steel_plate", amount = 3},
-    {item = "mechanical_parts", amount = 1},
-    {item = "circuit_board", amount = 1},
-]
+inputs = [{item = "steel_plate", amount = 2}, {item = "copper_wire", amount = 1}]
 outputs = [{item = "frigate_hull", amount = 1}]
-duration_seconds = 8.0
+duration_seconds = 2.0
 
 [[recipe]]
 id = "destroyer_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [
-    {item = "steel_plate", amount = 5},
-    {item = "mechanical_parts", amount = 2},
-    {item = "circuit_board", amount = 1},
-]
+inputs = [{item = "steel_plate", amount = 3}, {item = "copper_coil", amount = 2}]
 outputs = [{item = "destroyer_hull", amount = 1}]
-duration_seconds = 10.0
+duration_seconds = 4.0
 
 [[recipe]]
 id = "cruiser_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [
-    {item = "titanium_frame", amount = 2},
-    {item = "steel_plate", amount = 4},
-    {item = "drive_unit", amount = 1},
-]
+inputs = [{item = "hardened_steel", amount = 2}, {item = "control_chip", amount = 2}]
 outputs = [{item = "cruiser_hull", amount = 1}]
-duration_seconds = 15.0
+duration_seconds = 6.0
 
 [[recipe]]
 id = "battlecruiser_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
-    {item = "titanium_frame", amount = 3},
-    {item = "steel_plate", amount = 6},
+    {item = "hardened_steel", amount = 3},
+    {item = "control_chip", amount = 2},
     {item = "drive_unit", amount = 1},
-    {item = "targeting_unit", amount = 1},
 ]
 outputs = [{item = "battlecruiser_hull", amount = 1}]
-duration_seconds = 20.0
+duration_seconds = 8.0
 
 [[recipe]]
 id = "battleship_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
-    {item = "titanium_frame", amount = 4},
-    {item = "reinforced_plating", amount = 2},
-    {item = "drive_unit", amount = 2},
+    {item = "voidsteel_plate", amount = 3},
+    {item = "drive_unit", amount = 1},
+    {item = "control_chip", amount = 2},
 ]
 outputs = [{item = "battleship_hull", amount = 1}]
-duration_seconds = 30.0
+duration_seconds = 10.0
 
 [[recipe]]
 id = "dreadnought_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
+    {item = "voidsteel_plate", amount = 5},
     {item = "capital_core", amount = 1},
-    {item = "titanium_frame", amount = 6},
-    {item = "reinforced_plating", amount = 4},
     {item = "drive_unit", amount = 2},
 ]
 outputs = [{item = "dreadnought_hull", amount = 1}]
-duration_seconds = 60.0
+duration_seconds = 12.0
 
 [[recipe]]
 id = "carrier_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
+    {item = "voidsteel_plate", amount = 5},
     {item = "capital_core", amount = 1},
-    {item = "titanium_frame", amount = 5},
-    {item = "reinforced_plating", amount = 3},
     {item = "drive_unit", amount = 2},
 ]
 outputs = [{item = "carrier_hull", amount = 1}]
-duration_seconds = 60.0
+duration_seconds = 12.0
+
+# -----------------------------------------------------------------------------
+# Module prefabs
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "railgun_s_module"
+building = "assembler"
+inputs = [{item = "copper_coil", amount = 1}]
+outputs = [{item = "railgun_s_module", amount = 1}]
+duration_seconds = 1.0
+
+[[recipe]]
+id = "salvager_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_wire", amount = 2}]
+outputs = [{item = "salvager_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "repair_tool_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_wire", amount = 2}]
+outputs = [{item = "repair_tool_module", amount = 1}]
+duration_seconds = 2.0
+
+# Material-heavy, fast: the armor archetype.
+[[recipe]]
+id = "armor_plates_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 4}]
+outputs = [{item = "armor_plates_module", amount = 1}]
+duration_seconds = 3.0
+
+[[recipe]]
+id = "maneuvering_thrusters_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "maneuvering_thrusters_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "sensor_booster_module"
+building = "assembler"
+inputs = [{item = "copper_wire", amount = 2}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "sensor_booster_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "afterburner_module"
+building = "assembler"
+inputs = [{item = "copper_coil", amount = 2}, {item = "steel_plate", amount = 1}]
+outputs = [{item = "afterburner_module", amount = 1}]
+duration_seconds = 3.0
+
+[[recipe]]
+id = "weapon_stabilizer_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "weapon_stabilizer_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "weapon_primer_module"
+building = "assembler"
+inputs = [{item = "capacitor_bank", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "weapon_primer_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "weapon_upgrade_module"
+building = "assembler"
+inputs = [{item = "control_chip", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "weapon_upgrade_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "railgun_m_module"
+building = "assembler"
+inputs = [
+    {item = "capacitor_bank", amount = 1},
+    {item = "steel_plate", amount = 2},
+    {item = "copper_coil", amount = 1},
+]
+outputs = [{item = "railgun_m_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "drone_bay_module"
+building = "assembler"
+inputs = [
+    {item = "control_chip", amount = 1},
+    {item = "steel_plate", amount = 2},
+    {item = "copper_coil", amount = 1},
+]
+outputs = [{item = "drone_bay_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "railgun_l_module"
+building = "assembler"
+inputs = [
+    {item = "capacitor_bank", amount = 1},
+    {item = "hardened_steel", amount = 2},
+    {item = "ceramic_plate", amount = 1},
+]
+outputs = [{item = "railgun_l_module", amount = 1}]
+duration_seconds = 6.0
+
+[[recipe]]
+id = "drone_hangar_module"
+building = "assembler"
+inputs = [
+    {item = "voidsteel_plate", amount = 1},
+    {item = "control_chip", amount = 2},
+    {item = "drive_unit", amount = 1},
+]
+outputs = [{item = "drone_hangar_module", amount = 1}]
+duration_seconds = 10.0

bin/app/data/config/ships.toml

@@ -24,21 +24,21 @@
 id = "drone"
 unlock_at_station_level = -1
 layout = ["O"]
-default_modules = [{type = "laser_cannon_s", x = 0, y = 0, rotation = "east"}]
+default_modules = [{type = "railgun_s", x = 0, y = 0, rotation = "east"}]
 
 [ship.schematic]
-materials = [{item = "iron_ore", amount = 1}]
-production_time_seconds = 5
+materials = [{item = "drone_hull", amount = 1}]
+production_time_seconds = 1
 
 [ship.health]
-hp = 3
+hp = 60
 
 [ship.movement]
-speed_mps = 40
-main_acceleration_mpss = 2
-maneuvering_acceleration_mpss = 1
-angular_acceleration_radpss = 12.56
-max_rotation_speed_radps = 6.28
+speed_mps = 45
+main_acceleration_mpss = 60
+maneuvering_acceleration_mpss = 30
+angular_acceleration_radpss = 12
+max_rotation_speed_radps = 6
 
 [ship.sensor]
 sensor_range_m = 150
@@ -55,18 +55,23 @@ layout = [
     "OOO",
     "XOX",
 ]
+default_modules = [
+    {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+    {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "frigate_hull", amount = 1}]
-production_time_seconds = 10
+production_time_seconds = 2
 
 [ship.health]
-hp = 30
+hp = 300
 
 [ship.movement]
-speed_mps = 30
-main_acceleration_mpss = 50
-maneuvering_acceleration_mpss = 25
+speed_mps = 35
+main_acceleration_mpss = 45
+maneuvering_acceleration_mpss = 22
 angular_acceleration_radpss = 8
 max_rotation_speed_radps = 4
 
@@ -79,23 +84,30 @@ sensor_range_m = 200
 # mount medium hardware.
 [[ship]]
 id = "destroyer"
-unlock_at_station_level = -1
+unlock_at_station_level = 0
 layout = [
     "OXOXO",
     "OOOOO",
 ]
+default_modules = [
+    {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+    {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+    {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "destroyer_hull", amount = 1}]
-production_time_seconds = 15
+production_time_seconds = 3
 
 [ship.health]
-hp = 50
+hp = 550
 
 [ship.movement]
-speed_mps = 25
-main_acceleration_mpss = 40
-maneuvering_acceleration_mpss = 20
+speed_mps = 30
+main_acceleration_mpss = 35
+maneuvering_acceleration_mpss = 18
 angular_acceleration_radpss = 6
 max_rotation_speed_radps = 3
 
@@ -108,25 +120,31 @@ sensor_range_m = 220
 # supports; no 3x3 area exists for an l gun.
 [[ship]]
 id = "cruiser"
-unlock_at_station_level = -1
+unlock_at_station_level = 2
 layout = [
     "XOOX",
     "OOOO",
     "OOOO",
     "XOOX",
 ]
+default_modules = [
+    {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+    {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+    {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "cruiser_hull", amount = 1}]
-production_time_seconds = 25
+production_time_seconds = 4
 
 [ship.health]
-hp = 120
+hp = 1500
 
 [ship.movement]
-speed_mps = 20
-main_acceleration_mpss = 30
-maneuvering_acceleration_mpss = 15
+speed_mps = 24
+main_acceleration_mpss = 25
+maneuvering_acceleration_mpss = 12
 angular_acceleration_radpss = 4
 max_rotation_speed_radps = 2
 
@@ -140,25 +158,34 @@ sensor_range_m = 250
 # stern leave no 3x3 area for an l gun and no 2x6 area for a drone hangar.
 [[ship]]
 id = "battlecruiser"
-unlock_at_station_level = -1
+unlock_at_station_level = 4
+unlock_requires = ["cruiser"]
 layout = [
     "OOXXOO",
     "OOOOOO",
     "XOOOOX",
     "XXOOXX",
 ]
+default_modules = [
+    {type = "railgun_m", x = 0, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 4, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 2, y = 3, rotation = "east"},
+    {type = "railgun_s", x = 1, y = 2, rotation = "east"},
+    {type = "railgun_s", x = 4, y = 2, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "battlecruiser_hull", amount = 1}]
-production_time_seconds = 35
+production_time_seconds = 5
 
 [ship.health]
-hp = 180
+hp = 2400
 
 [ship.movement]
-speed_mps = 18
-main_acceleration_mpss = 25
-maneuvering_acceleration_mpss = 12
+speed_mps = 20
+main_acceleration_mpss = 20
+maneuvering_acceleration_mpss = 10
 angular_acceleration_radpss = 3
 max_rotation_speed_radps = 1.5
 
@@ -174,7 +201,8 @@ sensor_range_m = 260
 # so no 2x6 drone hangar fits.
 [[ship]]
 id = "battleship"
-unlock_at_station_level = 1
+unlock_at_station_level = 6
+unlock_requires = ["battlecruiser"]
 layout = [
     "XOOOOX",
     "OOOOOO",
@@ -182,18 +210,26 @@ layout = [
     "OOOOOO",
     "XOOOOX",
 ]
+default_modules = [
+    {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+    {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+    {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+    {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "battleship_hull", amount = 1}]
-production_time_seconds = 60
+production_time_seconds = 6
 
 [ship.health]
-hp = 350
+hp = 6300
 
 [ship.movement]
-speed_mps = 14
-main_acceleration_mpss = 18
-maneuvering_acceleration_mpss = 8
+speed_mps = 15
+main_acceleration_mpss = 14
+maneuvering_acceleration_mpss = 7
 angular_acceleration_radpss = 2
 max_rotation_speed_radps = 1
 
@@ -208,7 +244,7 @@ sensor_range_m = 280
 # stay the only hangar hull. Bow and stern strips hold supports.
 [[ship]]
 id = "dreadnought"
-unlock_at_station_level = 2
+unlock_at_station_level = 8
 unlock_requires = ["battleship"]
 layout = [
     "XXXOOOOOXXX",
@@ -217,18 +253,28 @@ layout = [
     "OOOXOOOXOOO",
     "XXOOXXXOOXX",
 ]
+default_modules = [
+    {type = "railgun_l", x = 0, y = 1, rotation = "east"},
+    {type = "railgun_l", x = 4, y = 1, rotation = "east"},
+    {type = "railgun_l", x = 8, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 3, y = 0, rotation = "east"},
+    {type = "armor_plates", x = 5, y = 0, rotation = "east"},
+    {type = "armor_plates", x = 2, y = 4, rotation = "east"},
+    {type = "armor_plates", x = 7, y = 4, rotation = "east"},
+    {type = "railgun_s", x = 7, y = 0, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "dreadnought_hull", amount = 1}]
-production_time_seconds = 120
+production_time_seconds = 8
 
 [ship.health]
-hp = 800
+hp = 24000
 
 [ship.movement]
-speed_mps = 8
-main_acceleration_mpss = 10
-maneuvering_acceleration_mpss = 5
+speed_mps = 10
+main_acceleration_mpss = 8
+maneuvering_acceleration_mpss = 4
 angular_acceleration_radpss = 1
 max_rotation_speed_radps = 0.5
 
@@ -242,7 +288,8 @@ sensor_range_m = 300
 # the lower decks hold supports and 2x2 point-defense m guns.
 [[ship]]
 id = "carrier"
-unlock_at_station_level = -1
+unlock_at_station_level = 9
+unlock_requires = ["battleship"]
 layout = [
     "XOOOOOOOOX",
     "OOOOOOOOOO",
@@ -250,18 +297,26 @@ layout = [
     "XOOOOOOOOX",
     "XXXOOOOXXX",
 ]
+default_modules = [
+    {type = "drone_hangar", x = 2, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 3, y = 2, rotation = "east"},
+    {type = "railgun_m", x = 6, y = 2, rotation = "east"},
+    {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 8, y = 1, rotation = "east"},
+    {type = "sensor_booster", x = 3, y = 4, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "carrier_hull", amount = 1}]
-production_time_seconds = 120
+production_time_seconds = 8
 
 [ship.health]
-hp = 700
+hp = 24000
 
 [ship.movement]
-speed_mps = 9
-main_acceleration_mpss = 10
-maneuvering_acceleration_mpss = 5
+speed_mps = 10
+main_acceleration_mpss = 8
+maneuvering_acceleration_mpss = 4
 angular_acceleration_radpss = 1
 max_rotation_speed_radps = 0.5
 

bin/app/data/config/stations.toml

@@ -1,10 +1,18 @@
+# stations.toml
+#
+# Combat-pass anchors (see docs/balancing/targets.md, "Combat anchors"):
+# a fresh player defence station holds one early parity wave unaided; the
+# enemy station at level 0 matches the player station exactly and scales
+# with the push level x. Station scrap drops stay authored (pushing rewards
+# are tuned independently of ship production costs, REQ-RES-SCRAP-DROP).
+
 [hq]
 surface_mask = [
   "AAA",
   "AAA",
   "AAA",
 ]
-hp_formula = "1000"
+hp_formula = "5000"
 
 [player_station]
 surface_mask = [
@@ -12,19 +20,19 @@ surface_mask = [
   "SS",
 ]
 level = 1
-hp_formula = "300"
-damage_formula = "5"
-range_m_formula = "200"
+hp_formula = "3000"
+damage_formula = "25"
+range_m_formula = "120"
 fire_rate_hz_formula = "1"
-scrap_drop_formula = "10"
+scrap_drop_formula = "40"
 
 [enemy_station]
 surface_mask = [
   "SS",
   "SS",
 ]
-hp_formula = "300 + 150*x"
-damage_formula = "2 + 1*x"
-range_m_formula = "200"
-fire_rate_hz_formula = "1.0 + 0.2*x"
-scrap_drop_formula = "10 + 5*x"
+hp_formula = "3000 + 1500*x"
+damage_formula = "25 + 12*x"
+range_m_formula = "120"
+fire_rate_hz_formula = "1.0 + 0.1*x"
+scrap_drop_formula = "40 + 30*x"

bin/app/data/config/visuals.toml

@@ -116,11 +116,11 @@ outline = "#201010"
 fill    = "#c47a3a"
 outline = "#3a1a0a"
 
-[items.titanium_ore]
-fill    = "#9aa3ad"
-outline = "#2a2e33"
+[items.quartz]
+fill    = "#e0d4f0"
+outline = "#40345a"
 
-# --- ingots ---
+# --- smelted basics ---
 
 [items.iron_ingot]
 fill    = "#b0b0b8"
@@ -130,9 +130,9 @@ outline = "#202028"
 fill    = "#d48a4a"
 outline = "#402010"
 
-[items.titanium_ingot]
-fill    = "#c8d2dc"
-outline = "#3a4048"
+[items.silicon]
+fill    = "#33415e"
+outline = "#0e1420"
 
 # --- salvage loop ---
 
@@ -140,9 +140,9 @@ outline = "#3a4048"
 fill    = "#7a7268"
 outline = "#201a14"
 
-[items.advanced_alloy]
-fill    = "#a06acc"
-outline = "#201030"
+[items.voidsteel]
+fill    = "#4a3a6a"
+outline = "#151020"
 
 # --- basic components ---
 
@@ -154,9 +154,9 @@ outline = "#3a2008"
 fill    = "#8a92a0"
 outline = "#22262c"
 
-[items.circuit_board]
-fill    = "#2ea35a"
-outline = "#0a2a14"
+[items.copper_coil]
+fill    = "#d07030"
+outline = "#381808"
 
 [items.building_block]
 fill    = "#c8b070"
@@ -164,26 +164,30 @@ outline = "#302810"
 
 # --- advanced components ---
 
-[items.mechanical_parts]
-fill    = "#6f7a66"
-outline = "#1c2018"
+[items.control_chip]
+fill    = "#2ea35a"
+outline = "#0a2a14"
 
-[items.targeting_unit]
-fill    = "#3a9e8c"
-outline = "#0c2824"
+[items.capacitor_bank]
+fill    = "#d0a030"
+outline = "#302408"
+
+[items.hardened_steel]
+fill    = "#6a7280"
+outline = "#181c22"
+
+[items.ceramic_plate]
+fill    = "#e0d8c8"
+outline = "#3a3428"
 
 [items.drive_unit]
 fill    = "#4a6ad0"
 outline = "#101a38"
 
-[items.titanium_frame]
-fill    = "#b8c4d4"
-outline = "#343c48"
-
 # --- capital components ---
 
-[items.reinforced_plating]
-fill    = "#8a6ad0"
+[items.voidsteel_plate]
+fill    = "#7a5aaa"
 outline = "#1c1038"
 
 [items.capital_core]
@@ -192,15 +196,15 @@ outline = "#280c30"
 
 # --- module items ---
 
-[items.laser_cannon_s_module]
+[items.railgun_s_module]
 fill    = "#691313"
 outline = "#f3ff4f"
 
-[items.laser_cannon_m_module]
+[items.railgun_m_module]
 fill    = "#892020"
 outline = "#f3ff4f"
 
-[items.laser_cannon_l_module]
+[items.railgun_l_module]
 fill    = "#a92d2d"
 outline = "#f3ff4f"
 

bin/app/data/config/world.toml

@@ -1,9 +1,9 @@
 [world]
 height_tiles = 40
 refund_percentage = 100
-starting_building_blocks = 1000
-scrap_despawn_seconds = 30
-scrap_per_threat = 0.01
+starting_building_blocks = 200
+scrap_despawn_seconds = 120
+scrap_per_threat = 0.25
 tile_size_m = 10
 belt_speed_mps = 20
 tunnel_max_distance_tiles = 10
@@ -17,9 +17,18 @@ player_buffer_width_tiles = 20
 contest_zone_width_tiles = 60
 enemy_buffer_width_tiles = 20
 
+[scroll]
+# View pan speed (REQ-UI-SCROLL-SPEED): slow near the asteroid, fast across the
+# contest zone, with a linear ramp of the given width straddling each boundary.
+pan_speed_slow_tiles_per_second = 8.0
+pan_speed_fast_tiles_per_second = 24.0
+pan_ramp_band_width_tiles = 16
+
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+# x = expansions already purchased; ~1 per cycle mid-game, decelerating
+# to 2-3 cycles late (docs/balancing/derived.md).
+cost_building_blocks_formula = "300 + 50*x + 10*x*x"
 
 [push]
 push_expand_columns_tiles = 10
@@ -32,10 +41,13 @@ target_hysteresis         = 0.40                   # keep current target unless
 
 [artifacts]
 artifact_chance_formula = "0.05 * x"  # 5% chance per station level
-artifact_win_count      = 3
+artifact_win_count      = 5
 
 [waves]
-threat_rate_formula = "x"
+# Tuned against the factory-size curve (docs/balancing/targets.md, balancing
+# targets): stays below the player's achievable military output early,
+# crosses it around the late boundary (~cycle 15), overwhelms by ~24.
+threat_rate_formula = "2*x + 0.15*x*x"
 gap_min_seconds = 15
 gap_max_seconds = 45
 spawn_duration_seconds = 10

bin/balancing/data/balancing.toml

@@ -1,68 +1,397 @@
+# balancing.toml — canonical arena suite for the combat stats pass.
+#
+# Ship counts are chosen so both teams have (near-)equal total threat,
+# using the verified fitted threat values from tools/threat_report.py:
+#   drone 10.5, frigate 47, destroyer 99, cruiser 233.5,
+#   battlecruiser 354.5, battleship 722.5, dreadnought 1491.5,
+#   carrier 1436.5, glass destroyer (8 small guns) 92, repair drone 17.
+# Module arrays mirror the ships' default_modules loadouts unless a
+# doctrine variant is the point of the arena.
+#
+# Expectations: mirror matches and equal-threat cross-tier matchups should
+# be near-draws (power-per-threat rule); the two-to-one arena must be a
+# decisive win for the larger team. "Cruisers vs carrier" is EXPECTED to be
+# a loss for the carrier until the drone-launching capability exists — the
+# hangar is 224 threat of dead weight.
+
+# --- mirrors (sanity: symmetric outcomes, fight duration in the 30-60 s band) ---
+
 [[arena]]
-name = "Fighters vs Sniper"
-height_tiles = 20
+name = "Mirror: drones 20v20"
+height_tiles = 10
 player_buffer_width_tiles = 10
-contest_zone_width_tiles = 60
+contest_zone_width_tiles = 50
 enemy_buffer_width_tiles = 10
 
   [[arena.team]]
   name = "Alpha"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 5
+    count = 20
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
 
   [[arena.team]]
   name = "Beta"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 2
+    count = 20
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
-      {type = "weapon_stabilizer",  x = 1, y = 1, rotation = "east"},
-      {type = "weapon_stabilizer",  x = 1, y = 1, rotation = "east"},
-      {type = "weapon_upgrade",  x = 1, y = 1, rotation = "east"},
-      {type = "sensor_booster",  x = 1, y = 1, rotation = "east"},
-      {type = "sensor_booster",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
 
 [[arena]]
-name = "Fighters vs Supported"
-height_tiles = 20
+name = "Mirror: cruisers 6v6"
+height_tiles = 10
 player_buffer_width_tiles = 10
-contest_zone_width_tiles = 60
+contest_zone_width_tiles = 50
 enemy_buffer_width_tiles = 10
 
   [[arena.team]]
-  name = "Fighters"
+  name = "Alpha"
     [[arena.team.ship]]
-    schematic = "drone"
-    count = 5
+    schematic = "cruiser"
+    count = 6
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
     ]
 
   [[arena.team]]
-  name = "Supported"
+  name = "Beta"
     [[arena.team.ship]]
-    schematic = "drone"
-    count = 3
+    schematic = "cruiser"
+    count = 6
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
     ]
 
+[[arena]]
+name = "Mirror: battleships 2v2"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Alpha"
+    [[arena.team.ship]]
+    schematic = "battleship"
+    count = 2
+    modules = [
+      {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+      {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Beta"
+    [[arena.team.ship]]
+    schematic = "battleship"
+    count = 2
+    modules = [
+      {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+      {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+    ]
+
+# --- equal-threat cross-tier matchups (power-per-threat: expect near-draws) ---
+
+[[arena]]
+name = "Drone swarm vs cruisers (462 vs 467)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Swarm"
+    [[arena.team.ship]]
+    schematic = "drone"
+    count = 44
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Cruisers"
+    [[arena.team.ship]]
+    schematic = "cruiser"
+    count = 2
+    modules = [
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Frigates vs battleship (705 vs 723)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Frigates"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 15
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Battleship"
+    [[arena.team.ship]]
+    schematic = "battleship"
+    count = 1
+    modules = [
+      {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+      {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Destroyers vs dreadnought (1485 vs 1492)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Destroyers"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 15
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Dreadnought"
+    [[arena.team.ship]]
+    schematic = "dreadnought"
+    count = 1
+    modules = [
+      {type = "railgun_l", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_l", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_l", x = 8, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 3, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 5, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 2, y = 4, rotation = "east"},
+      {type = "armor_plates", x = 7, y = 4, rotation = "east"},
+      {type = "railgun_s", x = 7, y = 0, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Cruisers vs carrier (1401 vs 1437, carrier expected to lose)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Cruisers"
+    [[arena.team.ship]]
+    schematic = "cruiser"
+    count = 6
+    modules = [
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Carrier"
+    [[arena.team.ship]]
+    schematic = "carrier"
+    count = 1
+    modules = [
+      {type = "drone_hangar", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 2, rotation = "east"},
+      {type = "railgun_m", x = 6, y = 2, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 8, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 4, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Mixed mid vs battlecruisers (1394 vs 1418)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Mixed"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 7
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+    ]
+    [[arena.team.ship]]
+    schematic = "cruiser"
+    count = 3
+    modules = [
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Battlecruisers"
+    [[arena.team.ship]]
+    schematic = "battlecruiser"
+    count = 4
+    modules = [
+      {type = "railgun_m", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 2, y = 3, rotation = "east"},
+      {type = "railgun_s", x = 1, y = 2, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 2, rotation = "east"},
+    ]
+
+# --- asymmetric checks ---
+
+[[arena]]
+name = "Two to one (must be decisive)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Six"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 6
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Three"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 3
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Armored vs glass destroyers (1188 vs 1196)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Armored"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 12
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Glass"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 13
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 3, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 1, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Repair escort vs raw numbers (444 vs 444)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Escorted"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 8
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+    [[arena.team.ship]]
+    schematic = "drone"
+    count = 4
+    modules = [
+      {type = "repair_tool", x = 0, y = 0, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Raw"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 9
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
     [[arena.team.ship]]
     schematic = "drone"
     count = 2
     modules = [
-      {type = "repair_tool",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
 
 [[arena]]
-name = "Stations and Ships"
-height_tiles = 60
+name = "Station assault (2 stations + 105 vs 315)"
+height_tiles = 10
 player_buffer_width_tiles = 15
 contest_zone_width_tiles = 40
 enemy_buffer_width_tiles = 15
@@ -71,9 +400,9 @@ enemy_buffer_width_tiles = 15
   name = "Fortified"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 3
+    count = 10
     modules = [
-      {type = "laser_cannon_s",   x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
     [[arena.team.station]]
     type = "player_station"
@@ -90,7 +419,7 @@ enemy_buffer_width_tiles = 15
   name = "Swarm"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 8
+    count = 30
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]

bin/test/data/config/recipes.toml

@@ -92,3 +92,60 @@ duration_seconds = 3.0
   item = "advanced_alloy"
   amount = 1
   probability = 0.1
+
+# -------------------------------------------------------------------
+# Extra recipes for ThreatCostCalculator unit tests (fixes 6-9)
+# -------------------------------------------------------------------
+
+# Fix 6: scrap-consuming smelter recipe for iron_ingot. Because iron_ingot
+# already has a scrap-free smelter recipe above, this recipe must be excluded
+# from iron_ingot's threat computation.
+[[recipe]]
+id = "scrap_iron"
+building = "smelter"
+inputs = [{item = "scrap", amount = 1}]
+outputs = [{item = "iron_ingot", amount = 1}]
+duration_seconds = 1.0
+
+# Fix 7: a recipe that produces 2 items per cycle. Per-unit threat must
+# divide by the output amount.
+# dual_wire: (duration=3.0 + iron_ore(1.0)*1) / 2 = 4.0 / 2 = 2.0 per unit.
+[[recipe]]
+id = "dual_wire"
+building = "assembler"
+inputs = [{item = "iron_ore", amount = 1}]
+outputs = [{item = "dual_wire", amount = 2}]
+duration_seconds = 3.0
+
+# Fix 8: an item downstream of a reprocessing-only item (advanced_alloy).
+# advanced_alloy is resolved only by the reprocessing pass; downstream_product
+# can only resolve in a non-reprocessing pass that runs AFTER the reprocessing
+# pass, requiring proper fixpoint iteration.
+# downstream_product: 2.0 + advanced_alloy(80.0)*1 = 82.0
+[[recipe]]
+id = "downstream_product"
+building = "assembler"
+inputs = [{item = "advanced_alloy", amount = 1}]
+outputs = [{item = "downstream_product", amount = 1}]
+duration_seconds = 2.0
+
+# Fix 9: two recipes producing the same staggered_item. The cheap recipe
+# resolves before circuit_board is known; the expensive one requires
+# circuit_board. The item must be committed only once BOTH are computable,
+# so the result is max(cheap, expensive).
+# staggered_item_cheap:  1.0 + iron_ore(1.0)*1  =  2.0  (resolves early)
+# staggered_item_expensive: 1.0 + circuit_board(28.0)*1 = 29.0 (resolves later)
+# expected: max = 29.0
+[[recipe]]
+id = "staggered_item_cheap"
+building = "assembler"
+inputs = [{item = "iron_ore", amount = 1}]
+outputs = [{item = "staggered_item", amount = 1}]
+duration_seconds = 1.0
+
+[[recipe]]
+id = "staggered_item_expensive"
+building = "assembler"
+inputs = [{item = "circuit_board", amount = 1}]
+outputs = [{item = "staggered_item", amount = 1}]
+duration_seconds = 1.0

bin/test/data/config/world.toml

@@ -17,9 +17,14 @@ player_buffer_width_tiles = 10
 contest_zone_width_tiles = 30
 enemy_buffer_width_tiles = 15
 
+[scroll]
+pan_speed_slow_tiles_per_second = 8.0
+pan_speed_fast_tiles_per_second = 24.0
+pan_ramp_band_width_tiles = 16
+
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20

docs/balancing/README.md

@@ -0,0 +1,56 @@
+# Balancing Documentation
+
+Everything about balancing Dota Factory, separated by role:
+
+- **[rules.md](rules.md)** — the design rules and principles. Timeless;
+  changes only when the design changes.
+- **[targets.md](targets.md)** — the base numbers (roots/anchors) chosen
+  by design. Change these first; everything else re-derives.
+- **[derived.md](derived.md)** — the current tuned state of all derived
+  numbers, mirroring the configs. Updated whenever configs change.
+- **[process.md](process.md)** — how balancing is done: the pass order,
+  tuning discipline, tools, and the checklist for the next round.
+- **[history.md](history.md)** — chronological record of decisions,
+  findings, bugs, and arena rounds.
+
+Related: game content (hull grids, footprint gating, tree design and
+fiction) in [../content_design.md](../content_design.md); rules with
+REQ-* ids in [../requirements.md](../requirements.md).
+
+## Status
+
+First full balancing round complete (2026-07-06): targets → tree →
+numbers → threat-calculator parity → combat stats (arena-converged) →
+pacing. Next step: full-game playtests against the run-shape targets in
+`targets.md`.
+
+## Open action items
+
+Agreed changes that require edits to `requirements.md`, the code, or the
+configs. Completed items are removed (their outcomes live in
+`requirements.md`, `history.md`, and the git history).
+
+1. **Fill unfillable schematic slots with artifacts.** With duplicates
+   removed, the schematic drop pool can run dry — previously unreachable.
+   Decision: every slot in the choice dialog that cannot be filled with a
+   schematic because the eligible pool is exhausted is filled with an
+   artifact option instead (in addition to any artifact option granted by
+   the regular artifact roll). A push therefore always awards a full
+   dialog. Update REQ-DEF-SCHEMATIC-DROP.
+2. **Confirm wave scaling in playtests.** `threat_rate_formula` is the
+   only time-scaling axis; verify the tuned curve (see `derived.md`)
+   produces the intended difficulty race in real runs.
+3. **Gate shortcut-recipe drops on their inputs.** Extend the assembler
+   recipe schematic pool eligibility in REQ-DEF-SCHEMATIC-DROP: in
+   addition to the existing station-level and output-item checks, all of
+   the recipe's input item types must be implicitly unlocked as well.
+4. **Resource deposits.** Add a terrain deposit layer per the Resource
+   deposits rules (`rules.md`): deposit patches generated in expansion
+   columns (deterministic content per expansion, randomized placement
+   within the new columns), deposit rendering, and a miner condition (a
+   resource recipe is selectable only if the miner's footprint overlaps
+   at least one matching deposit tile). Touches REQ-BLD-MINER ("every
+   asteroid tile is equivalent" no longer holds),
+   REQ-GW-ASTEROID-EXPAND / REQ-EXP-*, `world.toml`, and `visuals.toml`.
+   Until this lands, quartz mines anywhere and the mid-game is
+   knowledge-gated only.

docs/balancing/derived.md

@@ -0,0 +1,164 @@
+# Derived Values (current tuned state)
+
+Everything here is derived from `targets.md` under the rules in
+`rules.md`, and mirrors the config files. Item threats, ship threats,
+ratios, and belt checks are verified by `tools/threat_report.py` — re-run
+it after any recipe or material change and update this file when values
+move. Combat stats were tuned empirically against the arena suite in
+`bin/balancing/data/balancing.toml` (round-by-round record in
+`history.md`).
+
+## Economy constants
+
+- `scrap_per_threat = 0.25` — 1 scrap per 4 threat destroyed (a cruiser
+  kill drops ~59 scrap); threat(scrap) = 4.
+- Scrap smelting: 1 scrap → 1 iron_ingot, 1 s — deliberately
+  value-losing; reprocessing is the value-preserving path.
+- Reprocessing: 4 scrap per cycle, 4 s; full-pool weights iron_ingot 30 /
+  copper_ingot 30 / silicon 20 / voidsteel 20 → threat(voidsteel)
+  = (4·4 + 4)/0.2 = 100.
+- `scrap_despawn_seconds = 120` (a capital kill drops hundreds of scrap,
+  collected one per salvage cycle).
+
+## Recipes and item threats
+
+(dur in seconds; threat is per output unit)
+
+| item | recipe | dur | out | threat |
+|---|---|---|---|---|
+| iron_ore / copper_ore | miner | 1 | 1 | 1 |
+| quartz | miner (deposit) | 2 | 1 | 2 |
+| iron_ingot | 1 iron_ore | 1 | 1 | 2 |
+| copper_ingot | 1 copper_ore | 1 | 1 | 2 |
+| silicon | 1 quartz | 2 | 1 | 4 |
+| steel_plate | 2 iron_ingot | 3 | 1 | 7 |
+| copper_wire | 1 copper_ingot | 1 | 2 | 1.5 |
+| copper_coil | 2 copper_wire | 1.5 | 1 | 4.5 |
+| building_block | 2 steel_plate | 2 | 4 | 4 |
+| control_chip | 1 silicon + 2 copper_wire | 5 | 1 | 12 |
+| capacitor_bank | 2 copper_coil + 1 silicon | 5 | 1 | 18 |
+| hardened_steel | 3 steel_plate | 12 | 1 | 33 |
+| ceramic_plate | 2 quartz | 4 | 1 | 8 |
+| drive_unit | 2 steel_plate + 2 copper_coil + 1 control_chip | 8 | 1 | 43 |
+| voidsteel_plate | 1 voidsteel + 1 hardened_steel | 8 | 1 | 141 |
+| capital_core | 2 voidsteel + 1 capacitor_bank + 1 control_chip | 10 | 1 | 240 |
+
+Shortcut recipes (drop-only; item threat stays defined by the base path
+via the max rule): `shortcut_steel_plate` 3 iron_ore → 1 plate (2 s,
+level 1), `shortcut_control_chip` 2 quartz → 1 chip (4 s, level 2),
+`shortcut_hardened_steel` 4 iron_ingot → 1 hardened (8 s, level 2).
+
+Ratio curve realized: t1 all 1:1 (miner:smelter); t2 clean 2:3
+(ingot→plate, wire→coil); t3 strange — 2:5 (silicon→chip), 3:5
+(coil→capacitor), 3:4 (plate→hardened, plate→drive); t4 inverted 3:2
+(hardened→voidsteel_plate). Belt check: worst input demand 1.33 items/s,
+under the ~2/s single-belt cap everywhere.
+
+## Module prefabs
+
+(contribution = item threat + module production time)
+
+| module | recipe | dur | mod. time | contribution |
+|---|---|---|---|---|
+| railgun_s | 1 copper_coil | 1 | 1 | 6.5 |
+| salvager | 1 steel_plate + 2 copper_wire | 2 | 1 | 13 |
+| repair_tool | 1 steel_plate + 2 copper_wire | 2 | 1 | 13 |
+| armor_plates | 4 steel_plate | 3 | 1 | 32 |
+| maneuvering_thrusters | 1 steel_plate + 1 copper_coil | 2 | 1 | 14.5 |
+| sensor_booster | 2 copper_wire + 1 copper_coil | 2 | 1 | 10.5 |
+| afterburner | 2 copper_coil + 1 steel_plate | 3 | 1 | 20 |
+| weapon_stabilizer | 1 steel_plate + 1 copper_coil | 2 | 1 | 14.5 |
+| weapon_primer | 1 capacitor_bank + 1 copper_coil | 4 | 2 | 28.5 |
+| weapon_upgrade | 1 control_chip + 1 copper_coil | 4 | 2 | 22.5 |
+| railgun_m | 1 capacitor_bank + 2 steel_plate + 1 copper_coil | 4 | 3 | 43.5 |
+| drone_bay | 1 control_chip + 2 steel_plate + 1 copper_coil | 4 | 3 | 37.5 |
+| railgun_l | 1 capacitor_bank + 2 hardened_steel + 1 ceramic_plate | 6 | 4 | 102 |
+| drone_hangar | 1 voidsteel_plate + 2 control_chip + 1 drive_unit | 10 | 6 | 224 |
+
+## Ships
+
+(fitted = hull item + ship base time + default loadout; the default
+loadouts are the `default_modules` used by enemy waves and are
+geometry-validated against the hull grids)
+
+| ship | hull recipe | dur | base | default loadout | fitted |
+|---|---|---|---|---|---|
+| drone | 1 iron_ingot | 1 | 1 | railgun_s | 10.5 |
+| frigate | 2 steel_plate + 1 copper_wire | 2 | 2 | 2× railgun_s, maneuvering_thrusters | 47 |
+| destroyer | 3 steel_plate + 2 copper_coil | 4 | 3 | 3× railgun_s, armor_plates, sensor_booster | 99 |
+| cruiser | 2 hardened_steel + 2 control_chip | 6 | 4 | 2× railgun_m, armor_plates, maneuvering_thrusters | 233.5 |
+| battlecruiser | 3 hardened_steel + 2 control_chip + 1 drive_unit | 8 | 5 | 3× railgun_m, armor_plates, 2× railgun_s | 354.5 |
+| battleship | 3 voidsteel_plate + 1 drive_unit + 2 control_chip | 10 | 6 | railgun_l, 2× railgun_m, weapon_stabilizer, 2× railgun_s | 722.5 |
+| dreadnought | 5 voidsteel_plate + 1 capital_core + 2 drive_unit | 12 | 8 | 3× railgun_l, 4× armor_plates, railgun_s | 1491.5 |
+| carrier | 5 voidsteel_plate + 1 capital_core + 2 drive_unit | 12 | 8 | drone_hangar, 2× railgun_m, 2× armor_plates, sensor_booster | 1436.5 |
+
+## Combat stats
+
+(arena-converged, 2026-07; see `history.md` rounds 1–5)
+
+**Weapons:** railgun_s 2 dmg × 2.0 Hz (4.0 DPS), range 50 m;
+railgun_m 14 × 1.5 (21), range 70; railgun_l 52 × 0.8 (41.6), range 100.
+
+**Hull HP** (15/threat prior + empirical trims): drone 60, frigate 300,
+destroyer 550, cruiser 1500, battlecruiser 2400, battleship 6300,
+dreadnought/carrier 24000.
+
+**Mobility ladder** (speed m/s | main accel | maneuvering | angular |
+max rot): drone 45|60|30|12|6, frigate 35|45|22|8|4,
+destroyer 30|35|18|6|3, cruiser 24|25|12|4|2, battlecruiser 20|20|10|3|1.5,
+battleship 15|14|7|2|1, dreadnought/carrier 10|8|4|1|0.5.
+Sensors: 150/200/220/250/260/280/300/350 m.
+
+**Other modules:** armor_plates +1200 HP; repair_tool 9 HP × 1 Hz,
+range 80; salvager range 60, cargo 20, 0.5 collections/s; afterburner
+×1.6 speed +60 accel; maneuvering_thrusters ×1.2 speed +10 maneuvering;
+sensor_booster +50 m; weapon_upgrade ×1.2 damage; weapon_primer ×1.2
+rate; weapon_stabilizer ×1.3 range ×0.8 rate.
+
+**Stations:** HQ 5000 HP. Player station 3000 HP, 25 dmg × 1 Hz,
+range 120, scrap 40. Enemy station: 3000+1500x HP, 25+12x dmg,
+1.0+0.1x Hz, range 120, scrap 40+30x (x = push level).
+
+## Pacing
+
+**Unlock ladder** (level → unlocks; ← marks `unlock_requires`; starting
+set at −1: drone, frigate, railgun_s, salvager, building_block recipe):
+
+| level | ships | modules | recipes |
+|---|---|---|---|
+| 0 | destroyer | repair_tool, armor_plates | |
+| 1 | | maneuvering_thrusters, sensor_booster | shortcut_steel_plate |
+| 2 | cruiser | railgun_m, afterburner | shortcut_control_chip, shortcut_hardened_steel |
+| 3 | | weapon_stabilizer | |
+| 4 | battlecruiser ← cruiser | weapon_primer, weapon_upgrade | |
+| 5 | | drone_bay | |
+| 6 | battleship ← battlecruiser | railgun_l ← railgun_m | |
+| 8 | dreadnought ← battleship | | |
+| 9 | carrier ← battleship | drone_hangar | |
+
+Level 0's pool has exactly three entries (a full first dialog). Level 2
+is the quartz gate: cruiser and railgun_m are the first schematics whose
+chains reach quartz; the shortcut outputs only become implicitly
+unlocked alongside them, so shortcuts cannot drop early.
+
+**Threat rate** `2*x + 0.15*x*x` (x = boss cycle counter), against the
+factory-size curve with ~half the player's output assumed military:
+
+| cycle x | rate (threat/s) | player military (≈ curve/2) |
+|---|---|---|
+| 2 | 4.6 | ~12 |
+| 6 | 17.4 | ~30 |
+| 15 | 63.8 | ~60 |
+| 20 | 100 | ~75 |
+| 24 | 134 | — |
+
+**Economy:** `starting_building_blocks = 200`; expansion cost formula
+`300 + 50*x + 10*x*x` (x = expansions already purchased: ~1 affordable
+per cycle mid-game at ~1/3 of block income, stretching to 2–3 cycles
+late — quadratic so costs outrun the roughly linear block income
+gradually, never with a hard wall); `artifact_win_count = 5` with
+`artifact_chance_formula = 0.05*x`. Building costs: belt 2, splitter 3,
+tunnels 5, miner 15, smelter 20, assembler 35, reprocessing plant 40,
+salvage bay 25, shipyard 60 — averaging ≈18 blocks per placed building
+(belts included), which meets the 4-minute doubling target at block
+threat 4.

docs/balancing/history.md

@@ -0,0 +1,96 @@
+# Balancing History
+
+Chronological record of the balancing work: what was decided, what was
+found, what changed. Current values live in `derived.md`; this file
+explains how they got there.
+
+## 2026-07-02/03 — rules and structural decisions
+
+- Rules document written (now `rules.md`): ratio curve, shortcut
+  recipes, refactorability, cost archetypes, threat model, growth curve.
+- Scrap derived from threat (`scrap_per_threat`), replacing authored
+  per-ship scrap drops; scrap threat became the constant
+  `1/scrap_per_threat`, removing the old min-scrap_drop derivation and
+  its circularity.
+- Duplicate schematic drops removed (no level-ups); ship/module levels
+  removed entirely — all time scaling lives in the threat rate, push
+  scaling stays on stations. Mk2 upgrade recipes noted as the future
+  per-item progression.
+- Growth-curve rules added: escalating expansion costs, designed
+  doubling time, growth limited by economy not waiting; resource
+  deposits designed (deposit-gated mid resource in expansion territory).
+- Production tree v2 decided: iron/copper everywhere (M-type asteroid),
+  quartz in geodes (mid), voidsteel battle-forged from scrap (late);
+  titanium dropped; lasers renamed to railguns, lasers reserved as a
+  future weapon type.
+
+## 2026-07-03 — targets, tree, numbers
+
+- Balancing targets fixed: ≤2 h run, phases 1–5/6–14/15+, factory curve
+  25/60/120/150, threat ladder, 25-ship swarm, block roots.
+- Tree structure drafted and numbers computed (recursive threat
+  calculator); ratio curve realized; fitted ships within 96–124% of the
+  strawman ladder (small end hot from fixed chain overhead — ladder
+  later adopted the achieved values).
+- **Rule bugs found by the numbers work:** the scrap→ingot smelter
+  recipe would inflate basic materials via the max rule (fixed:
+  scrap-consuming recipes are threat fallback only); recipe output
+  amounts were ignored (fixed: per-unit division); items downstream of
+  reprocessing-only items never resolved (fixed: fixpoint resolution);
+  a shortcut recipe resolving earlier than the base path silently
+  underpriced items (fixed: commit only when all eligible recipes are
+  computable). All four fixed in `ThreatCostCalculator` with tests, and
+  implemented in `tools/threat_report.py`.
+- v2 tree written into the configs; `default_modules` loadouts
+  geometry-validated (the numbers-pass loadouts for battlecruiser and
+  dreadnought were geometrically impossible — L-modifiers don't fit
+  beside full gun complements; corrected loadouts landed closer to the
+  ladder).
+
+## 2026-07-04 — combat stats, arena rounds 1–5
+
+Initial stats derived from the anchors (weapon DPS ≈0.6/threat flat,
+hull 15 HP/threat, armor 20/threat, repair 2 HP/s/threat, station
+range 200).
+
+- **Round 1:** concentrated fleets won all equal-threat cross-tier
+  matchups flawlessly; glass beat armored; repair escort flawless; two
+  stations shrugged off a 3× swarm. Changes: concentration tax on m/l
+  gun damage (railgun_m 17→14, railgun_l 70→52), armor 640→1000,
+  repair 25→12, station range 200→120. (Team-1 "bias" in mirrors later
+  shown to be noise.)
+- **Round 2 (EHP-margin logging added):** battleship +33% while
+  dreadnought −37% (stabilizer range + opposing armor); glass still
+  +11%. Changes: stabilizer range ×1.5→×1.3; per-hull trims introduced
+  (BC 2700→2500, BS 7500→7000, DN/CV 15500→19000).
+- **Round 3 (narrow lanes — geometry fixed into the fixture):**
+  DN closed to −11%, BS +22%, swarm flipped to +14% over cruisers,
+  glass +12% third time. Changes: armor 1000→1200, BC 2500→2000,
+  BS 7000→6300, DN/CV 19000→22500.
+- **Round 4:** glass-vs-armored resolved (+3% armored); noise floor
+  established (~±10%/run: BS ignored a −10% EHP cut; repair drifted
+  14→24% untouched). Convergence policy adopted: two-round signals only,
+  ±20% converged. Changes: BC 2000→2200, DN/CV 22500→24000; BS +23%
+  accepted as doctrine texture (mechanical range edge vs. pure small
+  fleets).
+- **Round 5 (durations logged; end-condition bug fixed upstream):**
+  TTK anchor validated (mirrors 23/71/95 s; DN-vs-swarm 214 s outlier
+  accepted); dreadnought +3%, everything else inside band. Final
+  changes: BC 2200→2400, repair 12→9 (persistent +24% escort margin).
+  **Combat pass declared converged.**
+
+## 2026-07-05/06 — pacing pass
+
+- Unlock ladder set (starting set drone/frigate/railgun_s/salvager;
+  quartz gate at level 2; capitals at 8–9 with `unlock_requires`
+  chains); threat rate `2*x + 0.15*x*x`; starting blocks 1000→200;
+  expansion 400 flat pending the cost formula; artifacts 3→5.
+- **Bug found:** the building_block recipe was silently locked at game
+  start (building blocks appear in no schematic's materials, so implicit
+  unlocking could never reach the recipe) — fixed with an explicit
+  `unlock_at_station_level = -1`.
+- Expansion cost formula implemented and set (`300 + 50*x + 10*x*x`):
+  quadratic, so costs outrun the roughly linear block income gradually
+  — ~1 expansion per cycle mid-game, 2–3 cycles apart late.
+- **First full balancing round complete.** Next: full-game playtests
+  against the run-shape targets.

docs/balancing/process.md

@@ -0,0 +1,98 @@
+# Balancing Process
+
+How balancing is done in this project: the pass order, the tuning
+discipline, and the tools. Refer to this when starting the next
+balancing round.
+
+## The pass order
+
+Each pass depends on the ones before it; a change in an earlier pass
+invalidates the later ones (but not vice versa). Redo from the earliest
+pass whose inputs changed.
+
+1. **Targets** (`targets.md`) — choose the root numbers: run shape,
+   factory curve, threat-cost ladder, fleet size, block roots, combat
+   anchors, pacing anchors. These are design decisions, not
+   measurements. Everything else is derived from them.
+2. **Tree structure** (`../content_design.md`) — items, chains,
+   what-consumes-what, per the production tree rules (one input per
+   phase transition, generic parts, archetypes, refactorability).
+   Structure only, no quantities.
+3. **Numbers** (`derived.md`, recipes/materials in the configs) —
+   quantities and durations so every fitted ship sums to its ladder
+   value, the ratio curve is realized, and the belt/buffer guardrails
+   hold. Verified computationally by `tools/threat_report.py`.
+4. **Calculator/tooling parity** — the game's `ThreatCostCalculator`
+   and `tools/threat_report.py` must produce identical values; the
+   Python tool is the design reference. Any semantic change to
+   REQ-THREAT-* needs both updated plus tests.
+5. **Combat stats** (arena-driven) — derive stats from the combat
+   anchors, then iterate against the arena suite
+   (`bin/balancing/data/balancing.toml`) until equal-threat matchups are
+   near-draws. Threat costs are stat-independent, so arena ship counts
+   stay valid across stat changes.
+6. **Pacing** — unlock ladder, `unlock_requires` edges, threat rate,
+   block/artifact/expansion values, per the pacing anchors.
+
+Then: **full-game playtests**, which are the only check for the pacing
+pass and feed back into targets.
+
+## Tuning discipline (learned in arena rounds 1–5)
+
+- **Change anchors, not symptoms.** When a class of results is off,
+  adjust the anchor that explains all of them (e.g. the concentration
+  tax) rather than individual stats.
+- **Fewest knobs per round.** Attribution dies when many knobs move at
+  once. Prefer one anchor change plus its mechanical compensations.
+- **Shared vs. local knobs.** Guns and module stats are shared across
+  many hulls — changing them moves many matchups. Per-hull HP moves
+  exactly one matchup; it is the designated per-ship trim knob on top of
+  the HP-per-threat prior.
+- **Mind the ride-alongs.** A module buff lands on every default loadout
+  containing it (e.g. an armor buff strengthens the destroyer swarm that
+  opposes the dreadnought). Compute the net effect per matchup before
+  choosing step sizes.
+- **Two-round signal policy.** Single arena runs re-roll by ~±10% EHP
+  margin; a margin inside ±20% counts as converged for v1. Only act on
+  signals that persist across two rounds.
+- **Arena geometry is part of the fixture.** Lane width/height changes
+  the results (full engagement vs. fleets slipping past); margins are
+  only comparable within the same geometry.
+- **Accept mechanical texture.** Not every deviation is a bug: a margin
+  that survives a stat change is mechanical (usually range/kiting under
+  the orbit AI) and may be desirable doctrine texture. Document the
+  acceptance in `targets.md` instead of chasing it.
+- **Range is the strongest stat** under the orbit AI — free approach
+  fire. Price range modifiers conservatively; station dominance is
+  controlled via range, not HP.
+
+## Tools
+
+- `tools/threat_report.py` — item threats, module contributions,
+  hull/fitted ship threats, producer:consumer ratios, belt feasibility;
+  reads the real configs. The design reference for threat semantics.
+- `tools/verify_recipes.py` — recipe tree closure, visuals coverage,
+  orphans, reprocessing-only items.
+- `tools/verify_layouts.py` — module footprint gating matrix per hull.
+- **Balancing tool** (`balancing` target) — parallel arena simulation of
+  `bin/balancing/data/balancing.toml`; logs winner, surviving counts,
+  team EHP %, and fight duration per arena. The suite covers: class
+  mirrors (expect near-mutual annihilation, symmetric winners),
+  equal-threat cross-tier matchups (expect near-draws — power-per-threat
+  made empirical), a 2:1 decisiveness check, doctrine matchups
+  (armored-vs-glass, repair-escort), and station assault.
+
+## Checklist for the next balancing round
+
+1. Pull; run `verify_recipes.py`, `verify_layouts.py`,
+   `threat_report.py`; compare against the tables in `derived.md`.
+2. If recipes/materials changed: re-check fitted threats vs. the ladder
+   in `targets.md`; update arena suite ship counts if fitted values
+   moved.
+3. Run the arena suite; read EHP margins and durations against the
+   expectations noted in `balancing.toml` and the anchors.
+4. Apply changes per the tuning discipline (two-round signals only);
+   record the round and its knob changes in `history.md`.
+5. Update `derived.md` where values moved; if an anchor moved, update
+   `targets.md` and state why.
+6. Commit and push (the review workflow reads the remote).

docs/balancing/rules.md

@@ -0,0 +1,333 @@
+# Balancing & Progression Rules
+
+Rules and principles that govern the production tree, progression pacing,
+and balancing. This document contains **rules only** — the chosen base
+numbers live in `targets.md`, everything derived from them in
+`derived.md`, and the concrete content in the config files and
+`../content_design.md`. All of those must follow the rules stated here.
+
+## Player-experience goals
+
+What each phase of a run should feel like:
+
+- **Early:** learning belts and ratios with forgiving chains. The building
+  block economy is the main constraint; the player bootstraps a
+  self-sustaining factory from the starting stock.
+- **Mid:** deeper chains, the first real ratio puzzles, and the first
+  meaningful drop decisions (which schematic, when to push).
+- **Late:** combat feeds the factory — capital production requires salvage.
+  Progress means extending and refactoring the existing factory, not
+  rebuilding it. Strange ratios are deliberate optimization puzzles.
+
+Overarching: an experienced player gains efficiency through **knowledge** —
+layout foresight, understanding chains, exploiting shortcut recipes — never
+through hidden mechanics. An inexperienced setup should not cost much more
+than an experienced one; experience pays off in how easily the factory
+adapts later (see Refactorability).
+
+## Resource phases
+
+- A run has exactly **four base inputs**:
+  1. Two mined resources available from the start, minable on **every**
+     asteroid tile.
+  2. A third mined resource unlocked mid-game, minable **only on deposit
+     patches** found in expansion territory (see Resource deposits).
+  3. A fourth input unlocked late-game, obtainable **only** from
+     reprocessing salvaged scrap.
+- The fourth input is the core loop hook: capital ship production requires
+  fighting (salvaging and reprocessing), not just mining.
+- Every gating has a fictional reason (concrete fiction in
+  `../content_design.md`): the asteroid is a metal-rich body, so its bulk
+  rock is minable anywhere; the mid resource sits in rare pockets; the
+  late input is battle-forged — created only in the violence of ship
+  destruction, which is why any wreck (including the player's own)
+  yields it and no foundry can make it.
+- The mid resource is **dual-gated**: schematics (knowledge, via drops)
+  and territory (deposits, via expansions). Tuning must guarantee the
+  deposit-bearing expansion is comfortably affordable by the time the
+  first mid-tier schematics drop, or those drops are dead picks.
+- There is no direct "resource unlock" mechanism. Miner recipes unlock
+  **implicitly** (REQ-LOCK-IMPLICIT) when some unlocked schematic's material
+  chain reaches that resource. Resource pacing is therefore controlled
+  through the `unlock_at_station_level` values of ships, modules, and
+  assembler recipe schematics — and the content must guarantee that the
+  chains actually connect (a mid-game schematic must require an item whose
+  chain reaches the mid resource, or it never unlocks).
+
+### Resource deposits
+
+- **Rule: freedom first, geography later.** The starting resources are
+  minable everywhere, so the player has full layout freedom while
+  learning. Later mined resources are bound to deposit patches — fixed
+  geography as a layout puzzle, introduced once the player is competent.
+- **Rule: deposits exist only in expansion territory.** Expansions buy
+  space *and* access to resource tiers — the second leg of the growth
+  curve (see Building block economy).
+- **Rule: patch area is the throughput cap.** Deposits never deplete but
+  are finite in area; the number of deposit tiles caps how many miners
+  the chain supports. Buying deeper expansions raises the throughput
+  ceiling of high-tier chains.
+- **Rule: no empty expansions.** Deposit content per expansion is
+  deterministic and config-defined; only the placement within the new
+  columns is randomized. Buying an expansion never rolls "nothing".
+- **Rule: mining is binary.** A miner whose footprint overlaps at least
+  one deposit tile of a resource can select that resource's recipe; no
+  partial-coverage rate scaling.
+- Deposits arrive at the periphery (expansions add columns on the left),
+  so each new chain starts in fresh space — supporting the
+  refactorability property — and high-tier chains have the longest belt
+  runs to the shipyards, escalating the logistics puzzle with tier.
+
+## Production tree rules
+
+### Structure
+
+- **Each phase transition adds exactly one new base input chain.** A base
+  input is a bottom-level resource entering the factory from outside — a
+  mined resource or the scrap-only input. The early game starts with two
+  ores as the baseline; the transition to mid adds one (the deposit-bound
+  mid resource), the transition to late adds one (the scrap-only input).
+  No transition ever introduces more than one unfamiliar bottom-level
+  chain, so the factory grows in one direction at a time.
+- **Intermediates are generic shared parts.** Keep the item count low —
+  modules and hulls of a tier draw from a shared pool of that tier's and
+  lower tiers' intermediates rather than each having bespoke inputs.
+- **Thematic naming over thematic items.** Inputs should be plausible for
+  what the recipe produces (crystals for lasers, heat sinks for bigger
+  lasers). Achieve this through naming and chain membership, not by adding
+  item types: rename a generic part, don't add a parallel one.
+
+### Ratios
+
+- **Ratio "niceness" degrades with tier.** The producer:consumer ratios
+  needed for 100% throughput follow a curve:
+  - Tier 1 (ore → basic material): trivially nice (e.g. 1:1 or 1:2
+    miner:smelter).
+  - Tier 2: slightly complex but still clean (e.g. 2:3).
+  - Higher tiers: increasingly strange ratios, as deliberate optimization
+    puzzles.
+- Exceptions in both directions are allowed when there is a reason — a
+  clean late chain as a breather, an odd early chain as a teaser — but the
+  curve is the default.
+
+### Shortcut recipes
+
+- Some strange chains get a **shortcut recipe**: an explicitly unlockable
+  assembler recipe schematic (`unlock_at_station_level ≥ 0`, drop-only per
+  REQ-LOCK-EXPLICIT) that skips a step (e.g. t1 → t3 directly) and yields
+  nice ratios for a chain whose base path is strange.
+- **Not every strange chain gets a shortcut.** Some strangeness is
+  permanent; the absence of a fix is a valid design choice.
+- **Shortcuts drop only for known chains.** A shortcut recipe enters the
+  drop pool only when both its input items and its output item are
+  already unlocked (in addition to the station level check). The player
+  is never offered a shortcut for a chain they have not built yet. The
+  output-item half of this check already exists in
+  REQ-DEF-SCHEMATIC-DROP; the input half is an open action item (see
+  `README.md`).
+- **Shortcuts are pure rewards, never balance factors.** An item's threat
+  value is the *maximum* across its producing recipes (REQ-THREAT-ITEM), so
+  unlocking a cheaper recipe does not lower the item's threat accounting —
+  the player gains real factory efficiency without their ships being
+  valued cheaper and without enemy wave budgets shifting. Consequently:
+  **balance every chain around its base (expensive) path**; the shortcut's
+  savings define the size of the reward.
+
+### Refactorability
+
+- **Rule (the property):** unlocking the next tier or size of a thing must
+  be a *local edit* of the existing production line — adding assemblers
+  and belts, or replacing a machine or two in place — never a rebuild of
+  the line.
+- **What this buys the player:** foresight pays off in space, not blocks.
+  An experienced player leaves a little slack in the middle of a line,
+  knowing the next size or tier upgrade means tearing out one assembler
+  and a few belts there and inserting the new step — plus maybe swapping
+  a recipe or two elsewhere — while the rest of the line keeps running
+  untouched.
+- **Default technique:** the bigger version introduces one new intermediate
+  that is produced from a subset of the smaller version's inputs (possibly
+  plus one additional low-tier material), and otherwise reuses the smaller
+  version's inputs. Existing lines keep running and feed the new
+  intermediate's assemblers.
+- The property is the rule; the technique is only the default. It may be
+  broken where it fights thematic plausibility, as long as the property
+  still holds.
+
+## Cost archetypes
+
+Every item has two cost knobs: **material quantity** and **cycle time**.
+Both feed the threat value identically (threat = recursive
+production-seconds, REQ-MOD-THREAT), so the split between them does not
+change what an item is *worth* — it changes what kind of **factory
+pressure** it creates:
+
+- **Material-heavy, fast** (e.g. armor plates): simple items; stress belt
+  throughput, splitter logistics, and miner/smelter counts.
+- **Time-heavy, lean** (e.g. shield modules): technically complex items;
+  few inputs — possibly higher-tier ones — but long cycles; stress
+  assembler counts and parallelization.
+
+**Rule:** each module family commits to a clear archetype, so factories
+supporting different fleet doctrines feel structurally different to build.
+
+## Threat model (balancing backbone)
+
+- Threat cost = total recursive production-seconds (REQ-MOD-THREAT). One
+  factory-second equals one threat; player output and enemy wave budgets
+  are denominated in the same currency.
+- **Rule: combat power per threat is roughly constant** across all ships,
+  modules, and tiers. Higher tiers are better per *ship* and per *module
+  slot*, not per invested factory-second — their advantage is
+  concentration (fewer, bigger things; slot geometry per
+  `../content_design.md`) and qualitative capabilities, not a better
+  exchange rate. Deviations from this rule are deliberate and documented.
+- **Difficulty race:** the enemy threat rate (`threat_rate_formula`) is
+  tuned against the factory output (threat/s) achievable by a competent
+  player — slightly below it early, crossing above it eventually. The game
+  is endless; enemy scaling must ultimately outpace any factory, and
+  player skill shifts *when*, not *whether*.
+- **All time scaling lives in the threat rate** — waves get bigger, ships
+  of a given schematic never get individually stronger. There is no ship
+  level dimension: stat formulas are plain values, and per-ship level
+  scaling does not exist. Push scaling on enemy defence stations is the
+  separate, player-triggered difficulty axis and keeps its level formulas.
+
+## Unlock & drop pacing
+
+- **Starting set rule:** the schematics unlocked at game start
+  (`unlock_at_station_level = -1`) must be exactly enough to reach the
+  first push unaided — a functioning block loop, small hulls, a basic
+  weapon, and the salvage loop. Nothing more.
+- The `unlock_at_station_level` ladder mirrors the resource phases:
+  mid-tier hulls/modules/recipes at low station levels, capital content at
+  higher levels. A schematic must not become available before the chains
+  its materials need can be unlocked alongside it.
+- **Schematics can require other schematics.** Beyond the station-level
+  gate, a schematic (ship, module, or assembler recipe) may list
+  prerequisite schematics (`unlock_requires`, REQ-LOCK-PREREQ) that must
+  already be unlocked before it enters the drop pool — e.g. the medium
+  gun requires the small gun; a future Mk2 requires its base version.
+  Station level gates the earliest *when*; prerequisites gate the
+  *order*, keeping drop offers coherent with what the player already
+  owns.
+- **No duplicate drops.** Ship and module schematics leave the drop pool
+  once owned, exactly as assembler recipe schematics already do. There are
+  no schematic level-ups; player power grows through unlock breadth and
+  factory scale only, which keeps power-per-threat exact on both sides.
+  The pool therefore shrinks over a run and late pushes increasingly offer
+  artifacts — intended: the late game is a race for the win condition.
+  Per-item progression may return later as Mk2 upgrade recipes (see Future
+  work), never as free level-ups.
+- **Artifacts trade power for progress.** Artifact options compete with
+  schematic picks in the same choice dialog; the artifact chance must be
+  tuned so that taking one is a real decision (giving up an unlock), not
+  automatic in either direction.
+
+## Scrap & reprocessing economy
+
+- Scrap is the bridge from combat back into the factory, with two sinks:
+  **smelting** (same basic materials as ore — the safe, boring option) and
+  **reprocessing** (probabilistic higher intermediates, including the
+  late-game input — the gamble that eventually becomes mandatory).
+- The reprocessing output pool renormalizes over implicitly unlocked items
+  (REQ-LOCK-REPROCESSING-POOL), so its output quality improves
+  automatically as the run progresses. **Rule:** weights are authored for
+  the *fully unlocked* pool state; early-game behavior falls out of
+  renormalization for free and needs no separate staging.
+- **Rule: ship scrap drops are derived, never authored.** A destroyed ship
+  drops `threat cost × scrap_per_threat` (a `world.toml` key), with the
+  threat cost computed from its actual hull plus installed modules
+  (REQ-MOD-THREAT) — a kitted-out ship drops more scrap than a bare hull
+  automatically. `ships.toml` carries no scrap value. Defence stations are
+  the exception: they keep authored `scrap_drop_formula`s, because pushing
+  rewards are tuned independently of ship production costs.
+- Consequence: the threat value of scrap is the constant
+  `1 / scrap_per_threat` (REQ-THREAT-SCRAP). The former min-`scrap_drop`
+  schematic derivation and its potential circularity are gone.
+- **Rule:** the late-game input's income rate meaningfully gates capital
+  production — unlocking a capital hull must not mean spamming it; the
+  input trickles in slowly enough that every capital ship is a noticeable
+  investment. The tuning target is relative, not absolute: assume a
+  reference player who destroys and salvages roughly the threat the game
+  spawns ("fighting at parity"), and tune `scrap_per_threat`, the
+  reprocessing weights, and capital material costs so that this player
+  affords roughly N capital ships per boss cycle. An absolute income rate
+  would be meaningless (income depends entirely on how much the player
+  fights) and would not self-scale; per boss cycle, the target tracks the
+  threat rate as it steps up.
+
+## Building block economy
+
+- Building blocks are the only global currency and the early game's
+  central constraint. The early game is a bootstrap problem: convert the
+  starting stock into a self-sustaining block loop before the first waves
+  bite.
+- **Rule:** the starting stock suffices for a minimal block loop plus the
+  first shipyard — with a little slack for beginner mistakes, but not
+  enough to skip the loop entirely.
+- **Rule: the growth curve lives here.** A saturated building produces
+  exactly 1 threat/s, so the player's output curve *is* their
+  building-count curve — shaping growth over a run means shaping the
+  block and space economy, there is nowhere else it can live. Intended
+  shape: exponential bootstrap (block-limited) → ramp
+  (expansion-limited) → asymptotic squeeze as expansion costs outrun
+  income, racing the enemy threat rate throughout.
+- **Rule: escalating expansion costs.** Expansion cost is a formula of
+  the number of expansions already purchased, rising steeply enough that
+  expansions eventually outrun any block income. The starting asteroid
+  is deliberately small — filled within the first boss cycle or two, so
+  the early exponential burst is a satisfying ramp, not a balance hole —
+  and from then on the output curve is the expansion curve. Blocks keep
+  a meaningful sink for the entire run, and "grow vs. army" stays a live
+  decision at every moment.
+- **Rule: designed doubling time.** Block production is a positive
+  feedback loop (blocks buy assemblers, assemblers make blocks); its
+  time constant is a designed quantity, never an accident of quantity
+  choice. The block chain's depth and the per-building costs are tuned
+  against a stated target of the form: "a factory spending X% of its
+  capacity on blocks doubles in ~T minutes."
+- **Rule: growth is limited by economy, never by waiting.** Construction
+  times stay short; the serial build queue must not be used as a growth
+  brake. Waiting for placed buildings to become operational — especially
+  at the start of a run — is frustration, not gameplay. All growth
+  limiting comes from block income and expansion pricing.
+- Note: block income has a structural ceiling — blocks enter the stock
+  through the HQ's single belt port, so income is capped at belt
+  throughput regardless of assembler count. Per-building costs should be
+  high enough that this cap can bind late-game (see the condensed-block
+  idea under Future work).
+
+## Numeric guardrails
+
+Constraints that every recipe must respect, independent of tuning:
+
+- **Belt throughput:** belt speed and per-tile capacity cap how fast a
+  single belt can feed an input. A recipe whose per-cycle inputs cannot be
+  sustained by one belt per input at 100% duty cycle is a *deliberate*
+  design (forcing parallel belts/splitters as part of a high-tier puzzle)
+  — never an accident of quantity choice.
+- **Buffer burstiness:** input buffers hold 2× the per-cycle amount
+  (REQ-MAT-INPUT-BUFFER), so large per-cycle quantities create bursty belt
+  demand. Low tiers prefer small quantities with short cycles; big-batch
+  recipes are reserved for high tiers where burstiness is part of the
+  puzzle.
+- **Cycle times scale with tier** monotonically — a higher-tier item never
+  has a shorter total chain time than a lower-tier item of the same role.
+
+## Future work
+
+- **Condensed building blocks** — a drop-unlockable shortcut-style
+  recipe that packs several blocks' worth of value into one belt item,
+  relieving the HQ intake ceiling (see Building block economy) as a
+  late-game reward. The ceiling is the puzzle, the drop is the fix —
+  same philosophy as shortcut recipes.
+- **Mk2 upgrade recipes** — the deferred design for per-item progression,
+  to revisit once the config has stabilized. A duplicate-style drop
+  unlocks a distinct `*_mk2` item whose recipe consumes the Mk1 item plus
+  higher-tier parts. This preserves power-per-threat (the extra power is
+  paid in real production-seconds, since threat is recursive), satisfies
+  the refactorability rule (the Mk1 line keeps running and feeds one new
+  assembler), and keeps balancing one-dimensional (no level variable
+  anywhere). Enemy-side progression happens via `default_modules`
+  variants per era instead of a level formula.

docs/balancing/targets.md

@@ -0,0 +1,104 @@
+# Balancing Targets (base numbers)
+
+The root numbers of the balancing. Everything in `derived.md` is tuned to
+hit these; when rebalancing, **change these first and re-derive — never
+patch derived values directly**. The rules these numbers follow live in
+`rules.md`.
+
+All time targets are in **game time**. The player can pause and
+accelerate, so real session length differs; playtests measure both. The
+time unit is the boss cycle (`world.toml boss_countdown_seconds`, 300 s).
+Destroying a station set advances the boss countdown by
+`boss_advance_seconds` (60 s), so cycles run shorter than nominal when
+pushing actively — targets deliberately ignore that.
+
+## Run shape
+
+1. **Run length** — a winning run takes up to 2 hours of game time: win
+   around boss cycle 20–24. Losing runs end earlier.
+2. **Phase boundaries** — early = cycles 1–5 (iron/copper, small hulls),
+   mid = cycles 6–14 (quartz, medium hulls), late = cycles 15+
+   (voidsteel, capitals). Push cadence: first station set around cycle
+   2–3, roughly one per cycle from mid onward — so the destroyed set's
+   level ℓ is reached around cycle ℓ+2.
+3. **Factory size curve** — producing buildings over time; when
+   saturated, output threat/s equals this count, so this curve IS the
+   player power curve: ~25 when the starting asteroid is full (end of
+   cycle 2), ~60 at the start of mid (cycle 6), ~120 at the start of
+   late (cycle 15), ~150 near the win. `threat_rate_formula` must remain
+   a fraction of this curve; buildings plus belts must physically fit
+   the asteroid plus affordable expansions.
+4. **Threat-cost ladder** — total production-seconds per *fitted* hull
+   (including the typical/default module loadout): drone 10.5,
+   frigate 47, destroyer 99, cruiser 233.5, battlecruiser 354.5,
+   battleship 722.5, dreadnought 1491.5, carrier 1436.5. Every
+   production chain must sum to its ladder value. (The original strawman
+   was 10/40/80/200/350/700/1500; the small end runs ~10–20% hot because
+   fixed chain overhead dominates small hulls — accepted, and the
+   achieved values adopted as the ladder. The ~×2-per-class curve shape
+   is the invariant.)
+5. **Fleet size** — swarm-leaning: ~25 player combat ships as the
+   standing mid-game fleet. Standing fleet = build cadence (4) × average
+   ship lifetime, so this target drives time-to-kill and therefore all
+   combat stat magnitudes.
+6. **Block economy roots** — bootstrap complete (starting asteroid full)
+   by the end of cycle 2; a factory spending ~30% of its capacity on
+   blocks doubles in ~4 minutes early game; one expansion affordable per
+   cycle at ~1/3 of block income mid-game, decelerating to one per 2–3
+   cycles late as escalating costs outrun income.
+
+## Combat anchors
+
+All combat stats derive from these; per-hull HP additionally carries
+empirical trims from arena rounds (values in `derived.md`).
+
+- **Weapon DPS per threat pays a concentration tax that grows with gun
+  size**: small ≈ 0.62, medium ≈ 0.48, large ≈ 0.41 DPS per threat of
+  weapon contribution, compensated by the range ladder 50/70/100 m.
+  Rationale: concentration itself (focus fire, no DPS loss to attrition,
+  range) is worth paying for — with a flat curve, concentrated fleets
+  win equal-threat fights outright (arena round 1).
+- **Hull HP = 15 per threat of hull contribution** as the prior; per-hull
+  HP is the empirical trim knob (guns are shared across hulls, hull HP
+  moves exactly one matchup). The arena consistently prices capitals as
+  *tanks with taxed guns* — capital hulls sit well above the prior.
+- **Armor HP ≈ 37 per threat** — a strong premium over hull HP because
+  armor is pure HP with no capability, and fights snowball: killing
+  removes enemy DPS, surviving merely delays — HP must be cheaper than
+  DPS.
+- **Repair ≈ 0.7 HP/s per threat** — in-combat sustain effectively
+  removes enemy DPS and must be priced like DPS, not like HP.
+- **TTK / fight duration**: parity fights in the 30–60 s band at
+  mid-game scale; capital mirrors ~90 s deliberately; the extreme
+  tank-vs-chip-damage matchup (dreadnought vs destroyer swarm, ~3.5 min)
+  is an accepted outlier.
+- **Mobility is monotone in size** — the smallest hulls are the fastest
+  and nimblest. Sensor ranges (150→350 m) always exceed weapon ranges.
+- **Weapon modifiers are capital economy**: a ×1.2 damage modifier at
+  ~22.5 threat beats adding a gun once a ship carries more than ~68
+  threat of weapons — modifiers pay off on gun-heavy big hulls, waste on
+  small ones. Range modifiers are the strongest and are priced/kept
+  small (×1.3): range is the dominant stat under the orbit AI (free
+  approach fire).
+- **Stations**: a fresh player station holds one early parity wave
+  unaided; the enemy station at level 0 matches the player station
+  exactly and scales per push level. Station range is the dominance
+  lever, not HP (at 4× a small gun's range, two stations annihilated a
+  3× threat swarm through approach fire alone).
+- **Accepted imbalances**: the carrier loses its equal-threat fights
+  until the drone-launching capability exists (the hangar is dead
+  threat) — fix by implementing drones, not stats. A pure smallest-ship
+  fleet modestly loses (~15–25%) to a range-fitted capital — desirable
+  doctrine texture; the fair anti-capital answer is the mixed fleet.
+
+## Pacing anchors
+
+- **Starting set** is the rule-minimum: drone, frigate, small gun,
+  salvager (plus the explicitly unlocked building-block recipe).
+- **Threat rate shape**: below the player's achievable military output
+  (≈ half the factory curve) early, crossing at the late boundary
+  (~cycle 15), overwhelming by ~cycle 24.
+- **Winning = five real decisions**: `artifact_win_count` is set so that
+  across a winning run's ~15–18 pushes (~7 cumulative artifact offers at
+  the current chance formula), the player must choose the artifact over
+  a schematic about five times.

docs/content_design.md

@@ -1,9 +1,10 @@
-# Content Design — Ships & Modules
+# Content Design — Ships, Modules & Production Tree
 
-First real-content iterations (June 2026). Pass 1 defined ship hull grids and
-module surface masks; pass 2 defined the production tree (recipes). Stats and
-threat costs in the config files are still placeholders for the balancing
-pass.
+The designed game content: hull layout grids, module footprints and the
+gating between them, and the production tree (items, chains, fiction).
+All numbers — quantities, durations, threat values, stats, unlock levels
+— live in the config files and are documented with their derivations in
+`docs/balancing/` (see `balancing/README.md` for the index).
 
 ## Design principle: footprint gating
 
@@ -17,12 +18,12 @@ and makes them trivially moddable through the config files alone.
 
 | Footprint | Modules | Smallest hull that fits it |
 |-----------|---------|----------------------------|
-| 1x1 | laser_cannon_s, salvager, repair_tool | drone |
+| 1x1 | railgun_s, salvager, repair_tool | drone |
 | 1x2 | maneuvering_thrusters, sensor_booster, armor_plates | frigate |
 | 1x3 | afterburner | frigate (eats most of it) |
 | L-shape (3 cells) | weapon_stabilizer, weapon_primer, weapon_upgrade | frigate |
-| 2x2 | laser_cannon_m, drone_bay | cruiser |
-| 3x3 | laser_cannon_l | battleship |
+| 2x2 | railgun_m, drone_bay | cruiser |
+| 3x3 | railgun_l | battleship |
 | 2x6 | drone_hangar | carrier (only) |
 
 ### Hull grids
@@ -131,64 +132,163 @@ drone hangar — carrier 1.
 
 ## Production tree
 
-Design principle: each game phase adds exactly one new base input chain, so
-factory complexity ramps alongside ship size.
+Designed against the rules in `docs/balancing/rules.md` (ratio curve,
+cost ladder, cost archetypes, refactorability). Quantities, durations,
+and threat values live in `docs/balancing/derived.md`.
 
-| Phase | New input | How acquired | Unlocks |
-|-------|-----------|--------------|---------|
-| early | iron_ore, copper_ore | mined | drone, frigate, destroyer; small guns and basic supports |
-| mid | titanium_ore | mined (3x slower than iron) | cruiser, battlecruiser; m guns, drone bay, weapon modifiers |
-| late | advanced_alloy | ONLY from reprocessing salvaged scrap | battleship, dreadnought, carrier; l guns, drone hangar |
+### Base inputs (4) and fiction
 
-The advanced_alloy gate is the core loop hook: capital ship production
-requires fighting (salvaging scrap from kills and reprocessing it), not just
-mining. The reprocessing plant turns 5 scrap into iron/copper/titanium ingots
-or advanced_alloy probabilistically.
+- **iron_ore, copper_ore** — from the start, minable on every asteroid
+  tile. Fiction: the asteroid is an M-type (metal) body — its bulk rock
+  *is* ore, which is why the shipyard operation was built here at all.
+- **quartz** — mid-game, minable only on geode deposit patches in
+  expansion territory (see the Resource deposits rules in
+  `docs/balancing/rules.md`; the deposit mechanic itself is an open
+  action item — until it lands, quartz mines anywhere). Fiction:
+  ordinary silicate dust is everywhere and worthless; chips and optics
+  need rare, pocket-bound optical-grade crystal.
+- **voidsteel** — late-game, obtained only by reprocessing scrap.
+  Fiction: battle-forged — formed when weapon plasma anneals hull metal
+  in the violence of ship destruction. Any wreck yields it, including the
+  player's own; no foundry can replicate it.
+- **titanium was dropped** (v1 tree). Its hull-gating role moved to
+  quartz-era control systems ("you can smelt all the steel you want, but
+  you cannot steer a battlecruiser without electronics") plus the
+  hardened-steel quality step (a deliberately long-running, time-heavy
+  recipe) — explicitly not sheer steel quantity alone.
 
-Intermediate components, by tier:
+### Material palette (fingerprints per family)
 
-- **Tier 2 (early):** copper_wire (copper), steel_plate (iron), circuit_board
-  (iron + wire), building_block (iron).
-- **Tier 3 (mid):** mechanical_parts (steel + iron), targeting_unit (circuits
-  + wire), drive_unit (steel + mechanical_parts + circuit), titanium_frame
-  (titanium + steel).
-- **Tier 4 (late):** reinforced_plating (steel + advanced_alloy),
-  capital_core (targeting_unit + drive_unit + 2 advanced_alloy).
+- **iron/steel** — structure.
+- **copper** — conduction and heat: wiring, coils, heat sinks.
+- **silicon family** (all derived from quartz): silicon (logic,
+  sensors), ceramics (heat shielding, insulators); glass/optics are cut
+  from v1 — their only consumers would be lasers, which are deferred.
+- **voidsteel** — capital-tier structure and exotics.
+- Deliberately skipped: carbon (mostly redundant with copper/ceramics),
+  plastics (drags in Factorio-style chemical chains; ceramics read more
+  sci-fi anyway), volatiles/ice (materials are build costs only — no
+  consumption mechanic to justify fuel).
 
-Hulls and modules consume intermediates of their tier: early items are built
-from tier-2 parts, midgame items require tier-3 parts (deeper chains, more
-assemblers), capital items require tier-4 parts (and therefore combat). Hull
-items are named `<ship>_hull`; module items `<module>_module`. Every item has
-an `[items.*]` entry in visuals.toml; hull item outlines match the ship's
-fleet color from `[ships.*]`.
+### Weapons
 
-Consistency is checked by `tools/verify_recipes.py` — re-run it after editing
-recipes, ship/module materials, or visuals:
+- All v1 weapons are **railguns** (`railgun_s/m/l`, renamed from the
+  laser placeholders; footprints and the gating matrix unchanged).
+  Implementation is instant damage application with no projectile and no
+  ammunition — the beam visual reads as a tracer round. Materials: iron
+  slugs, copper coils, steel rails — the starting-metal fingerprint.
+- **Lasers are reserved for later** as a genuinely distinct weapon type
+  (e.g. once projectile/ammunition mechanics exist for other families),
+  arriving with quartz optics. More weapon types are planned; railguns
+  are simply the baseline tech that ships with v1.
+- `drone_bay` and `drone_hangar` are footprint-only placeholders: the
+  drone-launching capability does not exist in the simulation yet, so
+  they define no capability section. The carrier is deliberately weak
+  until that capability lands (see the accepted imbalances in
+  `docs/balancing/targets.md`).
+
+### Tree structure
+
+Input lists only — quantities, durations, and per-item threat values are
+in `docs/balancing/derived.md` and the configs.
+
+**Mined (miner):** `iron_ore`, `copper_ore` (every tile), `quartz`
+(geode deposits in expansion territory).
+
+**Smelted (smelter — exactly one recipe per input item):**
+
+| output | input | ratio class |
+|---|---|---|
+| iron_ingot | iron_ore | nice (1:1) |
+| copper_ingot | copper_ore | nice |
+| silicon | quartz | mid entry |
+| iron_ingot | scrap | the safe, boring scrap sink |
+
+**Reprocessing pool (scrap):** `iron_ingot`, `copper_ingot`, `silicon`,
+`voidsteel` — the only source of voidsteel. Weights authored for the
+fully unlocked pool state.
+
+**Tier 2 — early intermediates (clean ratios, ~2:3):**
+
+| item | inputs | role |
+|---|---|---|
+| steel_plate | iron_ingot | structure backbone, highest volume |
+| copper_wire | copper_ingot | conductors |
+| copper_coil | copper_wire | electromagnets: railguns, thrusters |
+| building_block | steel_plate | depth-3 chain = the doubling-time knob |
+
+**Tier 3 — mid intermediates (strange ratios begin, need quartz):**
+
+| item | inputs | role |
+|---|---|---|
+| control_chip | silicon + copper_wire | electronics gate for m+ hulls |
+| capacitor_bank | copper_coil + silicon | power for railgun m/l |
+| hardened_steel | steel_plate (long cycle) | quality gate for m+ hulls; time-heavy |
+| ceramic_plate | quartz | heat shielding: drives, l guns, capitals |
+| drive_unit | steel_plate + copper_coil + control_chip | propulsion for m+ hulls |
+
+**Tier 4 — late intermediates (need voidsteel):**
+
+| item | inputs | role |
+|---|---|---|
+| voidsteel_plate | voidsteel + hardened_steel | capital structure |
+| capital_core | voidsteel + capacitor_bank + control_chip | capital heart |
+
+**Hull items** (`<ship>_hull`, assembler-made; the shipyard consumes the
+hull item plus module materials). The m+ hull gate is **both**
+hardened_steel (quality steel, the time-heavy step) *and* control_chip
+(electronics):
+
+| hull | inputs |
+|---|---|
+| drone_hull | iron_ingot |
+| frigate_hull | steel_plate + copper_wire |
+| destroyer_hull | steel_plate + copper_coil |
+| cruiser_hull | hardened_steel + control_chip |
+| battlecruiser_hull | hardened_steel + control_chip + drive_unit |
+| battleship_hull | voidsteel_plate + drive_unit + control_chip |
+| dreadnought_hull | voidsteel_plate + capital_core + drive_unit |
+| carrier_hull | voidsteel_plate + capital_core + drive_unit |
+
+**Module items** (`<module>_module`, assembler-made prefabs — kept as
+items so shipyard belt inputs stay simple and module production can be
+stockpiled):
+
+| module | inputs | archetype |
+|---|---|---|
+| railgun_s | copper_coil | lean |
+| salvager | steel_plate + copper_wire | balanced |
+| repair_tool | steel_plate + copper_wire | balanced |
+| armor_plates | steel_plate (many) | material-heavy, fast |
+| maneuvering_thrusters | steel_plate + copper_coil | balanced |
+| sensor_booster | copper_wire + copper_coil | lean (an antenna, no chip) |
+| afterburner | copper_coil + steel_plate | balanced |
+| weapon_stabilizer | steel_plate + copper_coil | balanced |
+| weapon_primer | capacitor_bank + copper_coil | mid; time-heavy |
+| weapon_upgrade | control_chip + copper_coil | mid; time-heavy |
+| railgun_m | capacitor_bank + steel_plate + copper_coil | mid |
+| drone_bay | control_chip + steel_plate + copper_coil | mid |
+| railgun_l | capacitor_bank + hardened_steel + ceramic_plate | late |
+| drone_hangar | voidsteel_plate + control_chip + drive_unit | late (carrier only) |
+
+**Refactorability check** (the default technique holds): railgun_s → m
+introduces capacitor_bank, built from a subset of the small gun's inputs
+(copper_coil) plus the new base resource (silicon); the m gun otherwise
+reuses the small gun's inputs. Hulls likewise: the cruiser adds
+hardening (fed by the existing steel line) and chips (fed by the new
+quartz territory) without touching the iron/copper core.
+
+**Shortcut recipes** (drop-only assembler schematics; not every strange
+chain gets one): `iron_ore → steel_plate` (skips the ingot step on the
+highest-volume chain), `quartz → control_chip` (skips silicon),
+`iron_ingot → hardened_steel` (a nicer-ratio route past the deliberately
+awkward hardening step).
+
+Consistency is checked by `tools/verify_recipes.py` — re-run it after
+editing recipes, ship/module materials, or visuals:
 
     python dota_factory/tools/verify_recipes.py
 
 It verifies every consumed item has a producer, every item has a visuals
-entry, flags orphaned items, and prints which items are reprocessing-only
-(currently exactly advanced_alloy).
-
-## Deliberate placeholders / open questions for later passes
-
-- All new hulls have `threat.cost_formula = "0"` so enemy waves do not spawn
-  them yet (WaveSystem treats any ship with positive threat cost as wave-
-  eligible, regardless of unlock level). The balancing pass should set real
-  threat costs together with `default_modules` loadouts so waves spawn them
-  armed.
-- All new hulls and all assembler recipes are `unlock_at_station_level = -1`
-  (available from the start) to make testing easy; the balancing pass should
-  stagger these so mid/lategame recipes drop as schematics from enemy defence
-  stations.
-- Recipe quantities and durations are a first guess, deliberately roughly
-  tiered (capital hulls ~60 s, drones 4 s); the balancing pass tunes them.
-- `drone_bay` and `drone_hangar` are footprint-only placeholders: the drone
-  launching capability does not exist in the simulation yet, so they define
-  no capability section.
-- Renames in this pass: `laser_cannon_xs` → `laser_cannon_s` (the old 2x2
-  `laser_cannon_s` became `laser_cannon_m`), `armor_plate` → `armor_plates`,
-  `manuvering_thrusters` → `maneuvering_thrusters` (typo fix). Test data
-  under `bin/test/data/config` intentionally still uses the old ids — it is
-  an independent fixture set.
+entry, flags orphaned items, and prints which items are
+reprocessing-only (currently exactly voidsteel).

docs/requirements.md

@@ -4,7 +4,7 @@
 
 Config files use the TOML format. The following config files drive game parameters:
 
-- **world.toml** — world dimensions, region widths, expansion amounts, building refund percentage, wave timing, boss wave timing, belt speed, starting building blocks, departure interval, ship orbit factor, rally orbit radius, scrap-per-threat conversion, combat target-selection parameters (target score formula, overclaim penalty formula, target hysteresis), artifact chance formula, and artifact win count.
+- **world.toml** — world dimensions, region widths, expansion amounts, building refund percentage, wave timing, boss wave timing, belt speed, starting building blocks, departure interval, ship orbit factor, rally orbit radius, scrap-per-threat conversion, combat target-selection parameters (target score formula, overclaim penalty formula, target hysteresis), artifact chance formula, artifact win count, and view pan speeds (slow and fast horizontal pan speed and pan ramp band width).
 - **buildings.toml** — building block cost and construction time per building type.
 - **recipes.toml** — crafting recipes: inputs, outputs, quantities, durations, and reprocessing plant probabilities. Assembler recipe entries may optionally define `unlock_at_station_level` (integer): -1 means the recipe is explicitly unlocked at game start; a value ≥ 0 means the recipe starts locked and a schematic for it can be awarded via defence station destruction (see REQ-LOCK-EXPLICIT, REQ-DEF-SCHEMATIC-DROP). An assembler recipe schematic entry may also define an optional `unlock_requires` list of prerequisite schematic ids (REQ-LOCK-PREREQ).
 - **ships.toml** — per schematic: a human-readable display name (used in the UI), hull stats (HP, max linear speed, sensor range, main acceleration, maneuvering acceleration, angular acceleration, max rotation speed) as plain values, required build materials, the station level at which the schematic becomes available for unlock (`unlock_at_station_level`; -1 means the player starts with the schematic already unlocked), an optional `unlock_requires` prerequisite list (REQ-LOCK-PREREQ), a layout grid defining the ship's module slots, and a `default_modules` list used for enemy wave ships (see REQ-WAV-DEFAULT-MODULES).
@@ -109,6 +109,8 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 - REQ-BLD-BELT-DRAG: For belts, the player can click and drag across multiple tiles to place a construction site on each tile in one gesture.
 - REQ-BLD-TUNNEL-AUTO-SWITCH: After the player successfully places a Tunnel Entry construction site, builder mode automatically switches to Tunnel Exit (and vice versa), preserving the current ghost rotation. This makes it easy to immediately place the paired end without manually selecting the complementary type.
 - REQ-BLD-DEMOLISH: The player can demolish a placed factory building. Demolition returns `world.toml [world].refund_percentage` percent of the original building block cost (default 75%) to the global stock. Exception: if the building is still in the construction queue (not yet fully built, including the one currently being constructed), it is removed from the queue and the **full** building block cost is refunded. The HQ and player defence stations cannot be demolished.
+- REQ-BLD-DEMOLISH-CLICK: While in demolish mode (REQ-UI-HOTKEYS, REQ-UI-DEMOLISH-BUTTON), left-clicking a placed factory building or construction site in the game world demolishes it, following the refund rules of REQ-BLD-DEMOLISH — the partial refund for built buildings and the full refund for still-queued construction sites. Clicking a building that cannot be demolished (the HQ or a player defence station, per REQ-BLD-DEMOLISH), or clicking empty world space, has no effect. Demolish mode stays active after a demolition so the player can demolish further buildings without re-entering the mode; it is exited via the Q toggle (REQ-UI-HOTKEYS) or the Demolish button (REQ-UI-DEMOLISH-BUTTON).
+- REQ-BLD-DEMOLISH-BOX: While in demolish mode (REQ-UI-HOTKEYS, REQ-UI-DEMOLISH-BUTTON), the player can click and drag a selection box in the game world. A selection rectangle is drawn while dragging, using the same box-drag gesture and coverage semantics as the multi-select box (REQ-UI-MULTI-SELECT). On mouse up, every placed factory building and construction site covered by the box is demolished, each following the refund rules of REQ-BLD-DEMOLISH — the partial refund for built buildings and the full refund for still-queued construction sites. Buildings that cannot be demolished (the HQ and player defence stations, per REQ-BLD-DEMOLISH) are excluded from the box demolition; ships and defence stations are never affected.
 - REQ-BLD-SITE-CONFIG: A construction site — a building that has been placed but is still queued or under construction (REQ-BLD-QUEUE) — can be selected and configured exactly like the equivalent operational building, before it finishes building. Whatever configuration the building type supports is available on the site: the recipe for a Miner or Assembler (REQ-UI-SELECT-BUTTON), the produced-ship schematic and its module layout for a Shipyard (REQ-UI-SELECT-BUTTON, REQ-MOD-UI-PREVIEW, REQ-MOD-UI-DIALOG), and the output filters for a Splitter (REQ-BLD-SPLITTER) — all set through the same Selected Building Panel controls (REQ-UI-CONFIG-INLINE). Only currently unlocked recipes and schematics are offered, exactly as for operational buildings (REQ-LOCK-UI-RECIPE, REQ-LOCK-UI-SCHEMATIC, REQ-LOCK-UI-SPLITTER). The configuration is stored on the construction site and carries over unchanged when construction completes, so the building becomes operational already configured. A construction site has no input/output buffers and runs no production cycle, so the buffer and production-progress portions of the panel (REQ-UI-SINGLE-SELECTION, REQ-UI-PRODUCTION-PROGRESS) are not shown for it; only its construction progress (REQ-UI-CONSTRUCTION-PROGRESS) and its configuration controls appear. (Blueprint placement already applies a stored recipe or schematic to a construction site on placement per REQ-UI-BLUEPRINT-PLACE; this requirement additionally lets the player set or change that configuration directly on an existing site.)
 
 ## Building Types
@@ -224,12 +226,13 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
   2. The `production_time_seconds` of every module instance in the configured layout.
   3. For every material required (the union of the ship's base materials and all module instance materials, with quantities summed per item type): the recursive production time of that material multiplied by the required quantity (see REQ-THREAT-ITEM).
 
-- REQ-THREAT-ITEM: The threat value of an item type (in seconds) is determined by the recipe that produces it:
-  - **Miner recipe**: the recipe's `duration_seconds`.
-  - **Smelter recipe**: the recipe's `duration_seconds` plus the sum of each input's threat value multiplied by that input's required quantity.
-  - **Assembler recipe**: the recipe's `duration_seconds` plus the sum of each input's threat value multiplied by that input's required quantity.
-  - **Reprocessing-only item** (an item type that has no miner, smelter, or assembler recipe producing it, and is only obtainable via reprocessing): `(scrap_threat × scrap_per_cycle + duration_seconds) / probability`, where `scrap_threat` is the threat value of scrap (see REQ-THREAT-SCRAP), `scrap_per_cycle` is the number of scrap consumed per reprocessing cycle, `duration_seconds` is the reprocessing cycle time, and `probability` is the normalized weight of that item in the reprocessing output pool.
-  - **Multiple recipes**: if an item type can be produced by more than one non-reprocessing recipe (miner, smelter, or assembler), its threat value is the **maximum** across all such recipes. The reprocessing path is only used when no other recipe exists.
+- REQ-THREAT-ITEM: The threat value of an item type (in production-seconds **per unit**) is determined by the recipe that produces it:
+  - **Miner recipe**: `duration_seconds / output_amount`, where `output_amount` is the number of units produced per cycle.
+  - **Smelter recipe**: `(duration_seconds + Σ (input_threat × input_amount)) / output_amount`, where the sum is over all inputs.
+  - **Assembler recipe**: `(duration_seconds + Σ (input_threat × input_amount)) / output_amount`, where the sum is over all inputs.
+  - **Reprocessing-only item** (an item type that has no miner, smelter, or assembler recipe producing it, and is only obtainable via reprocessing): `(scrap_threat × scrap_per_cycle + duration_seconds) / probability`, where `scrap_threat` is the threat value of scrap (see REQ-THREAT-SCRAP), `scrap_per_cycle` is the number of scrap consumed per reprocessing cycle, `duration_seconds` is the reprocessing cycle time, and `probability` is the normalized weight of that item in the reprocessing output pool. (Reprocessing output amounts are 1 in practice, so per-unit division is already implicit in the formula.)
+  - **Multiple recipes**: if an item type can be produced by more than one non-reprocessing recipe (miner, smelter, or assembler), its threat value is the **maximum** across **all** such eligible recipes, and the threat is committed only once every eligible recipe is computable (so a shallow shortcut recipe that resolves earlier than a deeper base recipe cannot lower the item's threat). The reprocessing path is only used when no other recipe exists. If recipe cycles prevent full resolution, the max over the currently computable subset is used as a fallback.
+  - **Scrap-consuming recipe fallback**: a non-reprocessing recipe that takes `scrap` as an input participates in an item's threat computation only if no scrap-free recipe (miner, smelter, or assembler) produces that item. This mirrors the reprocessing fallback rule and prevents the scrap-to-ingot smelter recipe from inflating basic material threats via the max rule.
 
 - REQ-THREAT-SCRAP: The threat value of scrap is the constant `1 / world.toml [world].scrap_per_threat`. This is the exact inverse of the scrap-drop conversion in REQ-RES-SCRAP-DROP, so a destroyed ship drops scrap worth precisely its own threat cost. Because scrap threat is now a fixed constant, it no longer depends on any ship's threat cost, removing the potential circularity with REQ-MOD-THREAT for ships built from reprocessing-only materials.
 - REQ-MOD-STAT-CALC: For each stat (on the ship hull or on a capability module instance), the final value is computed as: `final = base × total_multiplier + total_additive`, where:
@@ -366,7 +369,7 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 ## Asteroid Expansion
 
 - REQ-EXP-UNLOCK: The player can unlock additional asteroid tile columns to the left of the existing asteroid by spending building blocks from the global stock.
-- REQ-EXP-COST: Each expansion adds `world.toml [expansion].columns_per_expansion` columns and costs `[expansion].cost_building_blocks` building blocks.
+- REQ-EXP-COST: Each expansion adds `world.toml [expansion].columns_per_expansion` columns. The building block cost of an expansion is defined by the formula `world.toml [expansion].cost_building_blocks_formula`, where `x` is the number of expansions already purchased (0 for the first expansion, incrementing by 1 for each subsequent expansion). The formula is evaluated at purchase time and its result is floored to an integer number of building blocks.
 
 ## UI
 
@@ -391,15 +394,22 @@ The screen is divided into two columns: a main column (75% width) containing the
            (75% width)                   (25% width)
 ```
 
-- REQ-UI-HEADER: The header bar spans the width of the game world column (75% of the screen width) and always shows the elapsed survival time, the current global building blocks stock, and the artifact count (REQ-WIN-ARTIFACT-COUNT) displayed as `Artifacts: x/y` (where `x` is the current artifact count and `y` is `world.toml [world].artifact_win_count`) on the left, the boss wave counter and boss countdown (REQ-UI-BOSS-STATUS) to the left of the speed buttons, and game speed controls on the right.
+- REQ-UI-HEADER: The header bar spans the width of the game world column (75% of the screen width) and always shows the elapsed survival time, the current global building blocks stock, and the artifact count (REQ-WIN-ARTIFACT-COUNT) displayed as `Artifacts: x/y` (where `x` is the current artifact count and `y` is `world.toml [world].artifact_win_count`) on the left, the boss wave counter and boss countdown (REQ-UI-BOSS-STATUS) and an asteroid expansion button (REQ-UI-EXPAND-BUTTON) to the left of the speed buttons, and game speed controls on the right.
 - REQ-UI-BOSS-STATUS: The header bar displays, to the left of the speed buttons, the current boss wave counter (REQ-WAV-BOSS-COUNTER) and the time remaining on the boss countdown (REQ-WAV-BOSS-COUNTDOWN). The boss wave counter is shown as `Boss Wave #<x>` and the countdown as `Next boss: <M:SS>`, where `<M:SS>` is the remaining seconds formatted as whole minutes and two-digit seconds. Both values update continuously as the simulation runs.
 - REQ-UI-SPEED: The game speed controls in the header bar are buttons for 0×, 0.5×, 1×, 2×, and 4× speed. The currently active speed is shown as selected. All game simulation (production, movement, threat accumulation, wave timing) scales with the selected speed. 0× pauses the game.
+- REQ-UI-EXPAND-BUTTON: The header bar shows an asteroid expansion button captioned `Expand: <x> Blocks`, where `<x>` is the current expansion cost computed from `world.toml [expansion].cost_building_blocks_formula` at the current number of purchased expansions (REQ-EXP-COST). Clicking the button unlocks the next asteroid expansion (REQ-EXP-UNLOCK, REQ-GW-ASTEROID-EXPAND), spending that many building blocks from the global stock. The button is disabled when the player cannot currently afford the cost (consistent with REQ-UI-BUILD-DISABLED). The caption updates as the cost changes with each purchased expansion.
 - REQ-UI-WORLD-SIZE: The game world view occupies the full height below the header bar in the main column (75% of the screen width).
 - REQ-UI-PANEL-COLUMN: The side panel column occupies 25% of the screen width and the full screen height. It is divided into three equal-height panels stacked top to bottom: selected building panel (top), build button grid (middle), and blueprint panel (bottom).
 
 ### Game World
 
-- REQ-UI-SCROLL: The player scrolls the view horizontally across the scrollable area by pressing A (scroll left) and D (scroll right).
+- REQ-UI-SCROLL: The player scrolls the view horizontally across the scrollable area by pressing A (scroll left) and D (scroll right). The pan speed is not constant; it varies with the view's position per REQ-UI-SCROLL-SPEED.
+- REQ-UI-SCROLL-SPEED: The horizontal pan speed varies with position so the player crosses the empty middle of the world quickly while retaining fine control near the asteroid and near the front line. Two pan speeds are read from `world.toml [scroll]`: `pan_speed_slow_tiles_per_second` (the base speed, used while the view is over the asteroid and player buffer zone) and `pan_speed_fast_tiles_per_second` (the faster speed, used while the view is over the contest zone). Both are expressed in tiles per second and apply equally to the A and D scroll directions. The current pan speed is a function of the view's horizontal center X (REQ-GW-REGIONS defines the regions):
+  - **Flat regions:** while the view center is left of the contest zone (over the asteroid or player buffer zone) and outside any ramp band, the pan speed is the slow speed; while the view center is inside the contest zone and outside any ramp band, the pan speed is the fast speed.
+  - **Ramp bands:** a transition ramp band of width `world.toml [scroll].pan_ramp_band_width_tiles` tiles straddles each contest-zone boundary (the player defence stations on the left, the enemy defence stations on the right), centered on the boundary with half the band width on each side. While the view center is within a ramp band, the pan speed is linearly interpolated between the slow speed at the band's outer (non-contest-zone) edge and the fast speed at the band's inner (contest-zone) edge, by the view center's fractional position across the band. This produces smooth speed changes when entering and exiting the fast contest-zone range rather than an abrupt jump.
+  - **Narrow contest zone:** should the two ramp bands overlap (a contest zone narrower than the band width), each ramp is clamped at the contest-zone center so the bands do not cross; the fast plateau then reduces to a single point at the center and the peak speed there may be below the fast speed.
+
+  Because the contest-zone boundaries shift as the scrollable area grows with each push (REQ-GW-PUSH-EXPAND, REQ-GW-SCROLL-LIMIT), the ramp bands are recomputed from the current contest-zone boundaries. This is a presentation-only concern and does not affect the simulation, consistent with REQ-UI-NO-ZOOM.
 - REQ-UI-CONSTRUCTION-PROGRESS: Construction sites display the building's glyph centered on the footprint (same as an operational building). Below the glyph — or centered on the footprint if the building has no glyph — a construction progress percentage is shown (integer, e.g. `42%`), increasing from 0% to 100% as construction completes.
 - REQ-UI-PORT-GLYPH: Every output port of every building is indicated by a directional glyph drawn on the port's tile. The glyph is a `>` rotated to face the port's exit direction (`>` for East, `^` for North, `<` for West, `v` for South). It is drawn at the midpoint between the tile center and the tile edge that the port exits through (i.e. halfway from center toward the exit edge). The indicator is rendered for all building states: operational buildings, construction sites, and the builder-mode ghost. Buildings with multiple output ports (e.g. splitters) show one indicator per port.
 - REQ-UI-HP-BARS: All entities with HP — the HQ, player and enemy defence stations, and player and enemy ships — render an HP bar below them. The bar is always visible regardless of current HP. The bar's filled portion represents the fraction of current HP to maximum HP.
@@ -511,13 +521,17 @@ A separate executable target (`balancing`) that links against `lib` but contains
 
 ### UI
 
-- REQ-BAL-UI-WINDOW: On startup the tool displays a window containing a "Reload Config" button and a "Start All" button at the top (in that order, left to right), followed by a scrollable vertical list of arena widgets, one per arena defined in `balancing.toml`. Simulations do not start automatically on startup. All buttons and controls in the main window are disabled while an arena is being inspected (REQ-BAL-UI-INSPECT).
+- REQ-BAL-UI-WINDOW: On startup the tool displays a window containing a "Reload Config" button, a "Start All" button, and a "Log" button at the top (in that order, left to right), followed by a scrollable vertical list of arena widgets, one per arena defined in `balancing.toml`. Simulations do not start automatically on startup. All buttons and controls in the main window are disabled while an arena is being inspected (REQ-BAL-UI-INSPECT).
 - REQ-BAL-UI-RELOAD: The "Reload Config" button reloads all config files from disk (`balancing.toml`, `ships.toml`, `stations.toml`), stops any running simulations, and replaces the arena widget list with freshly created widgets from the reloaded config. The button is disabled while any arena simulation is currently running.
 - REQ-BAL-UI-START-ALL: The "Start All" button is placed above the scrollable arena list, to the right of the "Reload Config" button. Clicking it starts (or restarts) the simulation for every arena that is not currently running. The button is disabled when all arenas are currently running.
-- REQ-BAL-UI-WIDGET: Each arena widget displays the arena name, an "Inspect" button (to the right of the arena name), and two columns (one per team). Each column shows the team name as a header, then directly below the header the team's **accumulated threat level** — the sum, across the team's configured ship entries, of each entry's `count` multiplied by the threat cost (REQ-MOD-THREAT) of one ship of that entry computed from its level-independent module layout. Only ships contribute; the HQ and defence stations are excluded. This value is static: it is computed once from the full configured roster and does not change as ships are destroyed during the fight. Below the threat level, the column shows a list of entries. The HQ is always the first entry in each column. Below the HQ, ship types are listed, followed by defence stations (if any). Each entry uses the format `surviving/total TypeName` for ship entries and `surviving/total TypeName Llevel` for the HQ and defence station entries — for example `2/3 Fighter`, `1/1 HQ L1`, or `2/2 Enemy Station L3`. The surviving count updates live as the simulation progresses. When the fight ends, the winning team's name header is prefixed with `[WON]`.
+- REQ-BAL-UI-LOG: The "Log" button is placed in the header to the right of the "Start All" button. It is enabled whenever the main window's controls are enabled — including while simulations are running (it captures a live snapshot) — and, like all main window controls, is disabled only while an arena is being inspected (REQ-BAL-UI-WINDOW). Clicking it writes the current state of every arena to a file named `balancing_log.md` in the tool's current working directory, replacing (overwriting) any previous content of that file. The log captures, for every arena in `balancing.toml` order, exactly the information shown in that arena's widget (REQ-BAL-UI-WIDGET) at the moment the button is clicked. Each arena is written as its own section:
+  - A heading with the arena name followed by the arena's current state — `not started`, `running`, or `ended` (corresponding to the widget border colors of REQ-BAL-UI-WIDGET-BORDER). For an `ended` arena, the heading also includes the battle duration (REQ-BAL-UI-WIDGET), for example `ended, 42.3 s`.
+  - A markdown table with one column per team (team 1 left, team 2 right). Each team's column header shows the team name — prefixed with `[WON]` when that team won, matching REQ-BAL-UI-WIDGET — the team's accumulated threat level, and the team's remaining EHP percentage (REQ-BAL-UI-WIDGET).
+  - Below the header, each table row holds one of that team's entries, in the same order and text format as the widget (REQ-BAL-UI-WIDGET): the HQ first, then ship types, then defence stations, formatted `surviving/total TypeName` for ship entries and `surviving/total TypeName Llevel` for the HQ and defence station entries. When the two teams have different numbers of entries, the shorter column's remaining cells are left blank.
+- REQ-BAL-UI-WIDGET: Each arena widget displays the arena name, an "Inspect" button (to the right of the arena name), and two columns (one per team). Each column shows the team name as a header, then directly below the header the team's **accumulated threat level** — the sum, across the team's configured ship entries, of each entry's `count` multiplied by the threat cost (REQ-MOD-THREAT) of one ship of that entry computed from its level-independent module layout. Only ships contribute; the HQ and defence stations are excluded. This value is static: it is computed once from the full configured roster and does not change as ships are destroyed during the fight. Directly below the threat level, the column shows the team's **remaining EHP percentage** — the sum of the current HP of all of the team's ships and defence stations, divided by the sum of their maximum HP, expressed as a percentage rounded to a whole number. Maximum HP is the final per-entity maximum (REQ-MOD-STAT-CALC), so module HP bonuses such as armor plates are included. (The game has no damage mitigation, so effective HP equals raw HP.) The HQ is excluded from both sums. A destroyed ship or station contributes 0 to the numerator and its maximum HP to the denominator, so the value measures how much of the team's fielded durability remains: it starts at 100% and decreases as units take damage or are destroyed. Unlike the static threat level, this value updates live as the simulation progresses. If the team has neither ships nor defence stations (the denominator is 0), the percentage is shown as `n/a`. Below the EHP percentage, the column shows a list of entries. The HQ is always the first entry in each column. Below the HQ, ship types are listed, followed by defence stations (if any). Each entry uses the format `surviving/total TypeName` for ship entries and `surviving/total TypeName Llevel` for the HQ and defence station entries — for example `2/3 Fighter`, `1/1 HQ L1`, or `2/2 Enemy Station L3`. The surviving count updates live as the simulation progresses. When the fight ends, the winning team's name header is prefixed with `[WON]`. When the fight has ended, the widget also displays the arena's **battle duration** — an arena-level value (not per team) giving the game time the fight lasted, computed as the number of simulated ticks at completion multiplied by the simulation's fixed tick duration (the same tick-based simulation as the main game, REQ-BAL-SIM-ENV). This is game time, not wall-clock time, so it is independent of how fast the arena was simulated (non-inspected arenas run at maximum tick rate, REQ-BAL-SIM-SPEED). It is shown in seconds with one decimal place, for example `Duration: 42.3 s`. The battle duration is shown only for completed (ended) runs; it is not shown while the arena is not started or running.
 - REQ-BAL-UI-WIDGET-START: Each arena widget contains a "Start" button that starts the simulation for that arena. The button is disabled while the arena's simulation is running. When a finished arena's Start button is clicked, a fresh simulation is created and started (the widget resets to initial unit counts, the border returns to blue, and the previous results are replaced).
 - REQ-BAL-UI-WIDGET-BORDER: Each arena widget has a colored border indicating its state: grey when not yet started, blue while its simulation is running, and green when the fight has ended.
 - REQ-BAL-UI-INSPECT: Clicking an arena widget's "Inspect" button opens a new inspect window for that arena. Any previously open inspect window is closed first (its arena's simulation is aborted and its widget border returns to grey). The inspected arena is restarted with a fresh simulation that runs at controllable game speed with full rendering (REQ-BAL-SIM-SPEED). The arena widget updates live during inspection (surviving counts, border color, `[WON]` prefix) as it does for non-inspected arenas. Only one inspect window may be open at a time.
-- REQ-BAL-UI-INSPECT-WINDOW: The inspect window consists of three sections, top to bottom: a title bar area containing the arena name and game speed controls (same buttons as the main game: 0×, 0.5×, 1×, 2×, 4×, with Space to toggle pause — see REQ-UI-SPEED and REQ-UI-HOTKEYS), the arena view in the center, and an info panel at the bottom displaying the same team columns and entry format as the arena widget in the main window (REQ-BAL-UI-WIDGET), updated live.
+- REQ-BAL-UI-INSPECT-WINDOW: The inspect window consists of three sections, top to bottom: a title bar area containing the arena name and game speed controls (same buttons as the main game: 0×, 0.5×, 1×, 2×, 4×, with Space to toggle pause — see REQ-UI-SPEED and REQ-UI-HOTKEYS), the arena view in the center, and an info panel at the bottom displaying the same team columns and entry format as the arena widget in the main window (REQ-BAL-UI-WIDGET), updated live, including the arena's battle duration once the fight has ended (REQ-BAL-UI-WIDGET).
 - REQ-BAL-UI-INSPECT-VIEW: The arena view renders all tiles of the arena and displays ships, HQs, defence stations, and laser beams using the same visual elements and `visuals.toml` colors as the main game. Team 1 uses player visual styles; team 2 uses enemy visual styles. The view has a fixed zoom level — no zoom or scroll is possible. The tile size is derived so that the full arena (all tiles) fits within the view.
 - REQ-BAL-UI-INSPECT-CLOSE: Closing the inspect window (via the window's close button) aborts the inspected arena's simulation. The arena widget's border returns to grey and its surviving counts are left as they were at the moment of closing. All main window buttons and controls are re-enabled.

src/balancing/ArenaSimulation.cpp

@@ -2,6 +2,8 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cmath>
+#include <string>
 
 #include <QVector2D>
 
@@ -86,12 +88,49 @@ ArenaSimulation::ArenaSimulation(const GameConfig& gameConfig,
 
     placeStructures();
     spawnShips();
+    computeTeamMaxEhp();
 
     m_shipSystem->triggerRallyDeparture();
 
     updateStatus();
 }
 
+std::string ArenaStatus::TeamStatus::ehpPercentText() const
+{
+    if (maxEhp <= 0.0)
+    {
+        return "n/a";
+    }
+    const int percent = static_cast<int>(std::lround(100.0 * currentEhp / maxEhp));
+    return std::to_string(percent) + "%";
+}
+
+void ArenaSimulation::computeTeamMaxEhp()
+{
+    m_teamMaxEhp[0] = 0.0;
+    m_teamMaxEhp[1] = 0.0;
+
+    // Ships contribute their full max HP.
+    m_admin.forEach<ShipIdentityComponent, FactionComponent, HealthComponent>(
+        [this](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
+               const FactionComponent& f, const HealthComponent& h)
+        {
+            m_teamMaxEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.maxHp);
+        });
+
+    // Defence stations contribute their full max HP; the HQ is excluded.
+    m_admin.forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+        [this](entt::entity e, const StationBodyComponent& /*sb*/,
+               const FactionComponent& f, const HealthComponent& h)
+        {
+            if (m_admin.hasAll<HqProxyComponent>(e))
+            {
+                return;
+            }
+            m_teamMaxEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.maxHp);
+        });
+}
+
 ArenaSimulation::~ArenaSimulation() = default;
 
 BuildingId ArenaSimulation::allocateBuildingId()
@@ -394,10 +433,13 @@ void ArenaSimulation::tickDeaths()
         });
 
     m_admin.forEach<StationBodyComponent, FactionComponent>(
-        [&team1HasUnits, &team2HasUnits](entt::entity /*e*/,
+        [this, &team1HasUnits, &team2HasUnits](entt::entity e,
                                           const StationBodyComponent& /*sb*/,
                                           const FactionComponent& f)
         {
+            // The HQ carries a StationBodyComponent but is not a defence station;
+            // its destruction is a separate end condition (REQ-BAL-SIM-END).
+            if (m_admin.hasAll<HqProxyComponent>(e)) { return; }
             if (f.isEnemy) { team2HasUnits = true; }
             else           { team1HasUnits = true; }
         });
@@ -476,12 +518,41 @@ void ArenaSimulation::updateStatus()
     ArenaStatus newStatus;
     newStatus.finished = m_finished;
     newStatus.winnerTeam = m_winnerTeam;
+    newStatus.durationSeconds = ticksToSeconds(m_currentTick);
+
+    // Live remaining HP of each team's ships and defence stations (HQ excluded);
+    // the EHP-percentage numerator (denominator is the fixed m_teamMaxEhp).
+    double currentEhp[2] = {0.0, 0.0};
+    m_admin.forEach<ShipIdentityComponent, FactionComponent, HealthComponent>(
+        [&currentEhp](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
+                      const FactionComponent& f, const HealthComponent& h)
+        {
+            if (h.hp > 0.0f)
+            {
+                currentEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.hp);
+            }
+        });
+    m_admin.forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+        [this, &currentEhp](entt::entity e, const StationBodyComponent& /*sb*/,
+                            const FactionComponent& f, const HealthComponent& h)
+        {
+            if (m_admin.hasAll<HqProxyComponent>(e))
+            {
+                return;
+            }
+            if (h.hp > 0.0f)
+            {
+                currentEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.hp);
+            }
+        });
 
     for (int ti = 0; ti < 2; ++ti)
     {
         ArenaStatus::TeamStatus& teamStatus = newStatus.teams[ti];
         teamStatus.name = m_arenaConfig.teams[ti].name;
         teamStatus.threatLevel = m_teamThreat[ti];
+        teamStatus.currentEhp = currentEhp[ti];
+        teamStatus.maxEhp = m_teamMaxEhp[ti];
 
         // HQ entry (always first).
         {

src/balancing/ArenaSimulation.h

@@ -44,12 +44,24 @@ struct ArenaStatus
     {
         std::string name;
         double threatLevel = 0.0;    // accumulated threat of the team's configured ships
+        // Remaining durability of the team's ships and defence stations (HQ
+        // excluded). currentEhp is summed live; maxEhp is the fixed full-HP
+        // baseline. See ehpPercentText() for the displayed value.
+        double currentEhp = 0.0;
+        double maxEhp = 0.0;
         std::vector<Entry> entries;  // HQ first, then ships, then stations
+
+        // Remaining EHP as a whole-number percentage ("NN%"), or "n/a" when the
+        // team has no ships or stations (maxEhp == 0).
+        std::string ehpPercentText() const;
     };
 
     TeamStatus teams[2];
     bool finished = false;
     int winnerTeam = -1;  // 0 or 1 when finished; -1 while running
+    // Game time the fight has lasted (simulated ticks * fixed tick duration).
+    // Meaningful once finished; the battle duration shown for completed runs.
+    double durationSeconds = 0.0;
 };
 
 class ArenaSimulation
@@ -82,6 +94,7 @@ private:
     BuildingId allocateBuildingId();
     void placeStructures();
     void spawnShips();
+    void computeTeamMaxEhp();
     void tick();
     void tickDeaths();
     void updateStatus();
@@ -115,6 +128,10 @@ private:
     // Static accumulated threat per team, computed once from the configured roster.
     double m_teamThreat[2] = {0.0, 0.0};
 
+    // Full-HP baseline per team (ships + defence stations, HQ excluded), computed
+    // once after spawning; the EHP-percentage denominator.
+    double m_teamMaxEhp[2] = {0.0, 0.0};
+
     std::vector<BeamFiredEvent> m_beamFiredEvents;
 
     mutable std::mutex m_statusMutex;

src/balancing/ArenaWidget.cpp

@@ -33,6 +33,9 @@ void ArenaWidget::buildLayout(const std::string& arenaName)
     m_titleLabel->setFont(titleFont);
     titleRow->addWidget(m_titleLabel);
 
+    m_durationLabel = new QLabel(this);
+    titleRow->addWidget(m_durationLabel);
+
     titleRow->addStretch();
 
     m_inspectButton = new QPushButton(tr("Inspect"), this);
@@ -63,6 +66,8 @@ void ArenaWidget::buildLayout(const std::string& arenaName)
     team1Layout->addWidget(m_team1Header);
     m_team1Threat = new QLabel(this);
     team1Layout->addWidget(m_team1Threat);
+    m_team1Ehp = new QLabel(this);
+    team1Layout->addWidget(m_team1Ehp);
     m_team1Content = new QLabel(this);
     team1Layout->addWidget(m_team1Content);
     team1Layout->addStretch();
@@ -75,6 +80,8 @@ void ArenaWidget::buildLayout(const std::string& arenaName)
     team2Layout->addWidget(m_team2Header);
     m_team2Threat = new QLabel(this);
     team2Layout->addWidget(m_team2Threat);
+    m_team2Ehp = new QLabel(this);
+    team2Layout->addWidget(m_team2Ehp);
     m_team2Content = new QLabel(this);
     team2Layout->addWidget(m_team2Content);
     team2Layout->addStretch();
@@ -99,13 +106,29 @@ void ArenaWidget::resetToGrey()
     setStyleSheet("ArenaWidget { border: 2px solid #999999; padding: 8px; }");
 }
 
+ArenaWidget::State ArenaWidget::getState() const
+{
+    if (m_wasFinished)
+    {
+        return State::Ended;
+    }
+    if (m_running)
+    {
+        return State::Running;
+    }
+    return State::NotStarted;
+}
+
 void ArenaWidget::updateStatus(const ArenaStatus& status)
 {
+    m_lastStatus = status;
+
     for (int ti = 0; ti < 2; ++ti)
     {
         const ArenaStatus::TeamStatus& team = status.teams[ti];
         QLabel* header = (ti == 0) ? m_team1Header : m_team2Header;
         QLabel* threat = (ti == 0) ? m_team1Threat : m_team2Threat;
+        QLabel* ehp = (ti == 0) ? m_team1Ehp : m_team2Ehp;
         QLabel* content = (ti == 0) ? m_team1Content : m_team2Content;
 
         if (status.finished && status.winnerTeam == ti)
@@ -118,6 +141,7 @@ void ArenaWidget::updateStatus(const ArenaStatus& status)
         }
 
         threat->setText(tr("Threat: %1").arg(QString::number(team.threatLevel, 'f', 0)));
+        ehp->setText(tr("EHP: %1").arg(QString::fromStdString(team.ehpPercentText())));
 
         QString lines;
         for (const ArenaStatus::Entry& entry : team.entries)
@@ -138,6 +162,10 @@ void ArenaWidget::updateStatus(const ArenaStatus& status)
         content->setText(lines);
     }
 
+    m_durationLabel->setText(status.finished
+        ? tr("Duration: %1 s").arg(QString::number(status.durationSeconds, 'f', 1))
+        : QString());
+
     if (status.finished && !m_wasFinished)
     {
         m_wasFinished = true;

src/balancing/ArenaWidget.h

@@ -14,21 +14,35 @@ class ArenaWidget : public QFrame
     Q_OBJECT
 
 public:
+    enum class State
+    {
+        NotStarted,
+        Running,
+        Ended
+    };
+
     ArenaWidget(int arenaIndex, const std::string& arenaName, QWidget* parent = nullptr);
 
     void updateStatus(const ArenaStatus& status);
     void startSimulation();
     void resetToGrey();
 
+    const ArenaStatus& getLastStatus() const { return m_lastStatus; }
+    State getState() const;
+
 private:
     void buildLayout(const std::string& arenaName);
 
     int m_arenaIndex;
+    ArenaStatus m_lastStatus;
     QLabel* m_titleLabel;
+    QLabel* m_durationLabel;
     QLabel* m_team1Header;
     QLabel* m_team2Header;
     QLabel* m_team1Threat;
     QLabel* m_team2Threat;
+    QLabel* m_team1Ehp;
+    QLabel* m_team2Ehp;
     QLabel* m_team1Content;
     QLabel* m_team2Content;
     QPushButton* m_inspectButton;

src/balancing/BalancingWindow.cpp

@@ -1,13 +1,70 @@
 #include "BalancingWindow.h"
 
+#include <algorithm>
+
+#include <QFile>
 #include <QHBoxLayout>
 #include <QMessageBox>
+#include <QTextStream>
 #include <QVBoxLayout>
 
 #include "ConfigLoader.h"
 #include "InspectWindow.h"
 #include "VisualsLoader.h"
 
+namespace
+{
+    // Escapes characters that would break a markdown table cell.
+    QString escapeCell(const QString& text)
+    {
+        QString escaped = text;
+        escaped.replace("|", "\\|");
+        return escaped;
+    }
+
+    QString stateText(ArenaWidget::State state)
+    {
+        switch (state)
+        {
+            case ArenaWidget::State::NotStarted:
+                return QStringLiteral("not started");
+            case ArenaWidget::State::Running:
+                return QStringLiteral("running");
+            case ArenaWidget::State::Ended:
+                return QStringLiteral("ended");
+        }
+        return QString();
+    }
+
+    // Team column header: "[WON] Name — threat N", matching the arena widget.
+    QString teamHeaderCell(const ArenaStatus& status, int teamIndex)
+    {
+        const ArenaStatus::TeamStatus& team = status.teams[teamIndex];
+        QString header = QString::fromStdString(team.name);
+        if (status.finished && status.winnerTeam == teamIndex)
+        {
+            header = QStringLiteral("[WON] ") + header;
+        }
+        header += QStringLiteral(" - threat %1").arg(QString::number(team.threatLevel, 'f', 0));
+        header += QStringLiteral(" - EHP %1").arg(QString::fromStdString(team.ehpPercentText()));
+        return escapeCell(header);
+    }
+
+    // Single entry line: "surviving/total DisplayName [L<level>]", matching the arena widget.
+    QString entryCell(const ArenaStatus::Entry& entry)
+    {
+        QString cell = QString("%1/%2 %3")
+                           .arg(entry.surviving)
+                           .arg(entry.total)
+                           .arg(QString::fromStdString(entry.displayName));
+        if (entry.level.has_value())
+        {
+            cell += QStringLiteral(" L%1").arg(entry.level.value());
+        }
+        return escapeCell(cell);
+    }
+}
+
 BalancingWindow::BalancingWindow(const BalancingConfig& balancingConfig,
                                  GameConfig gameConfig,
                                  const std::string& configDir,
@@ -31,13 +88,16 @@ BalancingWindow::BalancingWindow(const BalancingConfig& balancingConfig,
     QHBoxLayout* buttonRow = new QHBoxLayout();
     m_reloadButton = new QPushButton(tr("Reload Config"), this);
     m_startAllButton = new QPushButton(tr("Start All"), this);
+    m_logButton = new QPushButton(tr("Log"), this);
     buttonRow->addWidget(m_reloadButton);
     buttonRow->addWidget(m_startAllButton);
+    buttonRow->addWidget(m_logButton);
     buttonRow->addStretch();
     mainLayout->addLayout(buttonRow);
 
     connect(m_reloadButton, &QPushButton::clicked, this, &BalancingWindow::reloadConfig);
     connect(m_startAllButton, &QPushButton::clicked, this, &BalancingWindow::startAll);
+    connect(m_logButton, &QPushButton::clicked, this, &BalancingWindow::writeLog);
 
     m_scrollArea = new QScrollArea(this);
     m_scrollArea->setWidgetResizable(true);
@@ -255,6 +315,7 @@ void BalancingWindow::setMainControlsEnabled(bool enabled)
 {
     m_reloadButton->setEnabled(enabled);
     m_startAllButton->setEnabled(enabled);
+    m_logButton->setEnabled(enabled);
     for (ArenaEntry& entry : m_arenas)
     {
         for (QPushButton* btn : entry.widget->findChildren<QPushButton*>())
@@ -291,4 +352,58 @@ void BalancingWindow::updateButtons()
 
     m_reloadButton->setEnabled(!anyRunning);
     m_startAllButton->setEnabled(!allRunning);
+    m_logButton->setEnabled(true);
+}
+
+void BalancingWindow::writeLog()
+{
+    QFile file(QStringLiteral("balancing_log.md"));
+    if (!file.open(QIODevice::WriteOnly | QIODevice::Truncate | QIODevice::Text))
+    {
+        QMessageBox::warning(this, tr("Log Failed"),
+            tr("Could not open balancing_log.md for writing."));
+        return;
+    }
+
+    QTextStream out(&file);
+    out.setCodec("UTF-8");
+
+    out << "# Balancing Log\n";
+
+    for (const ArenaEntry& entry : m_arenas)
+    {
+        const ArenaStatus& status = entry.widget->getLastStatus();
+        const ArenaWidget::State state = entry.widget->getState();
+
+        QString stateSuffix = stateText(state);
+        if (state == ArenaWidget::State::Ended)
+        {
+            stateSuffix += QStringLiteral(", %1 s")
+                .arg(QString::number(status.durationSeconds, 'f', 1));
+        }
+
+        out << "\n## Arena: " << QString::fromStdString(entry.config.name)
+            << "  (" << stateSuffix << ")\n\n";
+
+        out << "| " << teamHeaderCell(status, 0) << " | "
+            << teamHeaderCell(status, 1) << " |\n";
+        out << "|---|---|\n";
+
+        const std::size_t rowCount = std::max(status.teams[0].entries.size(),
+                                              status.teams[1].entries.size());
+        for (std::size_t row = 0; row < rowCount; ++row)
+        {
+            QString leftCell;
+            if (row < status.teams[0].entries.size())
+            {
+                leftCell = entryCell(status.teams[0].entries[row]);
+            }
+            QString rightCell;
+            if (row < status.teams[1].entries.size())
+            {
+                rightCell = entryCell(status.teams[1].entries[row]);
+            }
+            out << "| " << leftCell << " | " << rightCell << " |\n";
+        }
+    }
 }

src/balancing/BalancingWindow.h

@@ -46,6 +46,7 @@ private slots:
     void pollStatuses();
     void reloadConfig();
     void startAll();
+    void writeLog();
 
 private:
     void startArena(int index);
@@ -72,6 +73,7 @@ private:
     unsigned int m_nextSeed;
     QPushButton* m_reloadButton;
     QPushButton* m_startAllButton;
+    QPushButton* m_logButton;
     QScrollArea* m_scrollArea;
     QTimer* m_pollTimer;
 

src/balancing/InspectWindow.cpp

@@ -52,6 +52,9 @@ InspectWindow::InspectWindow(ArenaSimulation* sim, const GameConfig* config,
         nameLabel->setFont(nameFont);
         headerLayout->addWidget(nameLabel);
 
+        m_durationLabel = new QLabel(header);
+        headerLayout->addWidget(m_durationLabel);
+
         headerLayout->addStretch();
 
         const char* labels[] = { "0x", "0.5x", "1x", "2x", "10x" };
@@ -93,6 +96,8 @@ InspectWindow::InspectWindow(ArenaSimulation* sim, const GameConfig* config,
         team1Layout->addWidget(m_team1Header);
         m_team1Threat = new QLabel(infoPanel);
         team1Layout->addWidget(m_team1Threat);
+        m_team1Ehp = new QLabel(infoPanel);
+        team1Layout->addWidget(m_team1Ehp);
         m_team1Content = new QLabel(infoPanel);
         team1Layout->addWidget(m_team1Content);
         team1Layout->addStretch();
@@ -104,6 +109,8 @@ InspectWindow::InspectWindow(ArenaSimulation* sim, const GameConfig* config,
         team2Layout->addWidget(m_team2Header);
         m_team2Threat = new QLabel(infoPanel);
         team2Layout->addWidget(m_team2Threat);
+        m_team2Ehp = new QLabel(infoPanel);
+        team2Layout->addWidget(m_team2Ehp);
         m_team2Content = new QLabel(infoPanel);
         team2Layout->addWidget(m_team2Content);
         team2Layout->addStretch();
@@ -198,11 +205,16 @@ void InspectWindow::pollStatus()
 
 void InspectWindow::updateInfoPanel(const ArenaStatus& status)
 {
+    m_durationLabel->setText(status.finished
+        ? tr("Duration: %1 s").arg(QString::number(status.durationSeconds, 'f', 1))
+        : QString());
+
     for (int ti = 0; ti < 2; ++ti)
     {
         const ArenaStatus::TeamStatus& team = status.teams[ti];
         QLabel* header  = (ti == 0) ? m_team1Header  : m_team2Header;
         QLabel* threat  = (ti == 0) ? m_team1Threat  : m_team2Threat;
+        QLabel* ehp     = (ti == 0) ? m_team1Ehp     : m_team2Ehp;
         QLabel* content = (ti == 0) ? m_team1Content  : m_team2Content;
 
         if (status.finished && status.winnerTeam == ti)
@@ -215,6 +227,7 @@ void InspectWindow::updateInfoPanel(const ArenaStatus& status)
         }
 
         threat->setText(tr("Threat: %1").arg(QString::number(team.threatLevel, 'f', 0)));
+        ehp->setText(tr("EHP: %1").arg(QString::fromStdString(team.ehpPercentText())));
 
         QString lines;
         for (const ArenaStatus::Entry& entry : team.entries)

src/balancing/InspectWindow.h

@@ -54,10 +54,13 @@ private:
     ArenaView*         m_arenaView;
 
     std::vector<QPushButton*> m_speedButtons;
+    QLabel* m_durationLabel;
     QLabel* m_team1Header;
     QLabel* m_team2Header;
     QLabel* m_team1Threat;
     QLabel* m_team2Threat;
+    QLabel* m_team1Ehp;
+    QLabel* m_team2Ehp;
     QLabel* m_team1Content;
     QLabel* m_team2Content;
     QTimer* m_pollTimer;

src/lib/config/ConfigLoader.cpp

@@ -278,8 +278,8 @@ WorldConfig ConfigLoader::loadWorld(const std::string& path)
     cfg.regions.contestZoneWidth_tiles  = static_cast<int>(requireInt(tbl["regions"]["contest_zone_width_tiles"],  file, "regions.contest_zone_width_tiles"));
     cfg.regions.enemyBufferWidth_tiles  = static_cast<int>(requireInt(tbl["regions"]["enemy_buffer_width_tiles"],  file, "regions.enemy_buffer_width_tiles"));
 
-    cfg.expansion.columnsPerExpansion_tiles = static_cast<int>(requireInt(tbl["expansion"]["columns_per_expansion_tiles"], file, "expansion.columns_per_expansion_tiles"));
-    cfg.expansion.costBuildingBlocks        = static_cast<int>(requireInt(tbl["expansion"]["cost_building_blocks"],        file, "expansion.cost_building_blocks"));
+    cfg.expansion.columnsPerExpansion_tiles   = static_cast<int>(requireInt(tbl["expansion"]["columns_per_expansion_tiles"], file, "expansion.columns_per_expansion_tiles"));
+    cfg.expansion.costBuildingBlocksFormula   = requireFormula(tbl["expansion"]["cost_building_blocks_formula"],            file, "expansion.cost_building_blocks_formula");
 
     cfg.push.pushExpandColumns_tiles = static_cast<int>(requireInt(tbl["push"]["push_expand_columns_tiles"], file, "push.push_expand_columns_tiles"));
     cfg.push.bossAdvanceSeconds = requireDouble(tbl["push"]["boss_advance_seconds"], file, "push.boss_advance_seconds");
@@ -305,6 +305,10 @@ WorldConfig ConfigLoader::loadWorld(const std::string& path)
     cfg.artifacts.artifactChanceFormula = requireFormula(tbl["artifacts"]["artifact_chance_formula"], file, "artifacts.artifact_chance_formula");
     cfg.artifacts.artifactWinCount      = static_cast<int>(requireInt(tbl["artifacts"]["artifact_win_count"], file, "artifacts.artifact_win_count"));
 
+    cfg.scroll.panSpeedSlow_tps       = requireDouble(tbl["scroll"]["pan_speed_slow_tiles_per_second"], file, "scroll.pan_speed_slow_tiles_per_second");
+    cfg.scroll.panSpeedFast_tps       = requireDouble(tbl["scroll"]["pan_speed_fast_tiles_per_second"], file, "scroll.pan_speed_fast_tiles_per_second");
+    cfg.scroll.panRampBandWidth_tiles = static_cast<int>(requireInt(tbl["scroll"]["pan_ramp_band_width_tiles"], file, "scroll.pan_ramp_band_width_tiles"));
+
     return cfg;
 }
 

src/lib/config/WorldConfig.h

@@ -14,8 +14,8 @@ struct WorldRegions
 // Asteroid expansion (REQ-EXP-UNLOCK, REQ-EXP-COST).
 struct WorldExpansion
 {
-    int columnsPerExpansion_tiles;
-    int costBuildingBlocks;
+    int     columnsPerExpansion_tiles;
+    Formula costBuildingBlocksFormula;  // cost in building blocks; x = expansions already purchased
 };
 
 // Push effects (REQ-PSH-*, REQ-WAV-BOSS-ADVANCE).
@@ -53,6 +53,14 @@ struct WorldArtifacts
     int     artifactWinCount;
 };
 
+// View pan speed (REQ-UI-SCROLL-SPEED). Presentation-only; the simulation ignores these.
+struct WorldScroll
+{
+    double panSpeedSlow_tps;        // tiles/s, used outside the contest zone
+    double panSpeedFast_tps;        // tiles/s, used inside the contest zone
+    int    panRampBandWidth_tiles;  // full width of the ramp band straddling each contest-zone boundary
+};
+
 struct WorldConfig
 {
     int heightTiles;                    // REQ-GW-HEIGHT
@@ -73,4 +81,5 @@ struct WorldConfig
     WorldWaves waves;
     WorldTargeting targeting;
     WorldArtifacts artifacts;
+    WorldScroll scroll;
 };

src/lib/eventsystem/event/CMakeLists.txt

@@ -3,6 +3,7 @@ SET(HDRS
 	${CMAKE_CURRENT_SOURCE_DIR}/TracePrintRequestedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/TickAdvancedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/BuildingBlocksChangedEvent.h
+	${CMAKE_CURRENT_SOURCE_DIR}/ExpansionCostChangedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/EntitySelectedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/GameSpeedChangedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/BossWaveUpdatedEvent.h
@@ -30,6 +31,7 @@ SET(HDRS
 	${CMAKE_CURRENT_SOURCE_DIR}/BeamFiredEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/DebugDrawToggledEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/CommandRequestedEvent.h
+	${CMAKE_CURRENT_SOURCE_DIR}/PlayerCommandsAppliedEvent.h
 	PARENT_SCOPE
 )
 

src/lib/eventsystem/event/ExpansionCostChangedEvent.h

@@ -0,0 +1,17 @@
+#ifndef EXPANSION_COST_CHANGED_EVENT_H
+#define EXPANSION_COST_CHANGED_EVENT_H
+
+#include "Event.h"
+
+// Fired when the current asteroid-expansion cost changes (REQ-EXP-COST): once at
+// startup and again after each expansion is purchased. Carries the cost in
+// building blocks so the header Expand button can update its caption/enabled
+// state (REQ-UI-EXPAND-BUTTON).
+class ExpansionCostChangedEvent : public Event
+{
+public:
+	explicit ExpansionCostChangedEvent(int cost) : cost(cost) {}
+	const int cost;
+};
+
+#endif   // EXPANSION_COST_CHANGED_EVENT_H

src/lib/eventsystem/event/PlayerCommandsAppliedEvent.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "Event.h"
+
+// Emitted by GameWorldView once per frame after queued player commands have been
+// drained and applied to the simulation. It lets presentation widgets refresh
+// even while the game is paused (no tick advances, so no TickAdvancedEvent), for
+// example so a shipyard's layout preview appears immediately after its schematic
+// is chosen. It is a UI notification only and never feeds back into the command
+// queue, so it has no effect on replay recording or determinism.
+class PlayerCommandsAppliedEvent : public Event
+{
+};

src/lib/sim/BuildingSystem.cpp

@@ -24,6 +24,7 @@ BuildingSystem::BuildingSystem(const GameConfig& config,
     , m_spawnShip(std::move(spawnShip))
     , m_isItemUnlocked(std::move(isItemUnlocked))
     , m_rng(rng)
+    , m_asteroidWidth_tiles(config.world.regions.asteroidWidth_tiles)
 {
 }
 
@@ -281,7 +282,7 @@ bool BuildingSystem::bodyCellsWithinWorldBounds(const std::vector<QPoint>& bodyC
                                                 QPoint anchor) const
 {
     const int heightTiles = m_config.world.heightTiles;
-    const int leftEdgeX   = -m_config.world.regions.asteroidWidth_tiles;
+    const int leftEdgeX   = -m_asteroidWidth_tiles;
     for (const QPoint& cell : bodyCells)
     {
         const QPoint worldCell = anchor + cell;

src/lib/sim/BuildingSystem.h

@@ -59,6 +59,11 @@ public:
     bool isPlacementValid(BuildingType type, QPoint anchor,
                           Rotation rotation) const;
 
+    // Sets the current buildable asteroid width in tiles. Grows the left
+    // placement bound as the player unlocks asteroid expansions (REQ-EXP-UNLOCK).
+    // Defaults to world.regions.asteroid_width_tiles at construction.
+    void setAsteroidWidth_tiles(int widthTiles) { m_asteroidWidth_tiles = widthTiles; }
+
     // Remove a building or construction site by id.  Returns the refund in
     // building blocks (floor(cost * refundPercentage / 100)).  Returns 0 for
     // unknown ids.
@@ -179,6 +184,7 @@ private:
                        const std::optional<ShipLayoutConfig>&)> m_spawnShip;
     std::function<bool(const std::string&)>        m_isItemUnlocked;
     std::mt19937&                                  m_rng;
+    int                                            m_asteroidWidth_tiles;
 
     std::vector<Building>           m_buildings;
     std::deque<ConstructionSite>    m_constructionQueue;

src/lib/sim/Command.h

@@ -35,6 +35,7 @@ enum class CommandKind
     SetSplitterFilters,
     ClearBeltTiles,
     ApplySchematicChoice,
+    ExpandAsteroid,
     Reset
 };
 
@@ -129,6 +130,14 @@ struct ApplySchematicChoiceCommand : Command
     int choiceIndex = 0;
 };
 
+// Unlocks the next asteroid expansion (REQ-EXP-UNLOCK). Carries no payload: the
+// simulation derives the cost and column count from its own expansion counter
+// and config, so a recorded command replays identically.
+struct ExpandAsteroidCommand : Command
+{
+    ExpandAsteroidCommand() : Command(CommandKind::ExpandAsteroid) {}
+};
+
 // Restart boundary: reinitializes the simulation with a fresh seed and, if
 // config is set, a reloaded config (GameConfig is move-only, so it is carried by
 // shared_ptr and moved into the sim on apply). A null config keeps the current

src/lib/sim/Simulation.cpp

@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cmath>
 
 #include "AiSystem.h"
 #include "Command.h"
@@ -132,6 +133,7 @@ void Simulation::reset(unsigned int seed)
     m_nextDepartureTick        = secondsToTicks(m_config.world.departureIntervalSeconds);
     m_nextBuildingId                   = 1;
     m_buildingBlocksStock      = m_config.world.startingBuildingBlocks;
+    m_expansionsPurchased      = 0;
     m_gameOver                      = false;
     m_isWon                         = false;
     m_artifactCount                 = 0;
@@ -275,6 +277,9 @@ void Simulation::apply(const Command& command)
     case CommandKind::ApplySchematicChoice:
         applySchematicChoice(static_cast<const ApplySchematicChoiceCommand&>(command).choiceIndex);
         break;
+    case CommandKind::ExpandAsteroid:
+        tryExpandAsteroid();
+        break;
     case CommandKind::Reset:
     {
         const ResetCommand& c = static_cast<const ResetCommand&>(command);
@@ -993,6 +998,7 @@ unsigned long long Simulation::computeStateChecksum() const
     hasher.append(m_gameOver);
     hasher.append(m_isWon);
     hasher.append(m_artifactCount);
+    hasher.append(m_expansionsPurchased);
 
     // WaveSystem scalar state, reached through existing accessors.
     hasher.append(threatLevel());
@@ -1100,6 +1106,31 @@ int Simulation::buildingBlocksStock() const
     return m_buildingBlocksStock;
 }
 
+int Simulation::currentAsteroidWidth_tiles() const
+{
+    return m_config.world.regions.asteroidWidth_tiles
+        + m_expansionsPurchased * m_config.world.expansion.columnsPerExpansion_tiles;
+}
+
+int Simulation::currentExpansionCost() const
+{
+    const double cost = m_config.world.expansion.costBuildingBlocksFormula.evaluate(
+        static_cast<double>(m_expansionsPurchased));
+    return static_cast<int>(std::floor(cost));
+}
+
+void Simulation::tryExpandAsteroid()
+{
+    const int cost = currentExpansionCost();
+    if (m_buildingBlocksStock < cost)
+    {
+        return;
+    }
+    m_buildingBlocksStock -= cost;
+    ++m_expansionsPurchased;
+    m_buildingSystem->setAsteroidWidth_tiles(currentAsteroidWidth_tiles());
+}
+
 bool Simulation::isGameOver() const
 {
     return m_gameOver;

src/lib/sim/Simulation.h

@@ -72,6 +72,12 @@ public:
     // The seed this run was (re)initialized with; written to the replay header.
     unsigned int getSeed()        const;
     int    buildingBlocksStock()  const;
+    // Current asteroid width in tiles = base width + purchased expansions
+    // (REQ-EXP-UNLOCK, REQ-GW-ASTEROID-EXPAND).
+    int    currentAsteroidWidth_tiles() const;
+    // Building block cost of the next expansion, floored to an integer
+    // (REQ-EXP-COST); x = number of expansions already purchased.
+    int    currentExpansionCost()  const;
     bool   isGameOver()           const;
     bool   isWon()                const;
     int    artifactCount()        const;
@@ -136,6 +142,11 @@ private:
     // Clears the pending choices after application.
     void applySchematicChoice(int choiceIndex);
 
+    // Unlocks one asteroid expansion if affordable (REQ-EXP-UNLOCK): checks the
+    // current cost against the stock, deducts it, increments the expansion
+    // counter, and widens the buildable asteroid. No-op if blocks are short.
+    void tryExpandAsteroid();
+
     // Mutable subsystem accessors; same chokepoint rule as the mutators above.
     BuildingSystem&       buildingsMutable();
     BeltSystem&           beltsMutable();
@@ -165,6 +176,7 @@ private:
     Tick     m_nextDepartureTick;
     BuildingId m_nextBuildingId;
     int      m_buildingBlocksStock;
+    int      m_expansionsPurchased = 0;  // REQ-EXP-COST formula variable x
     bool     m_gameOver    = false;
     bool     m_isWon       = false;
     int      m_artifactCount = 0;

src/lib/sim/ThreatCostCalculator.cpp

@@ -30,6 +30,7 @@ double computeMaterialThreat(const ThreatCostTable& table,
     return total;
 }
 
+// Returns true if every input of the recipe has a resolved threat value.
 bool allInputsResolved(const RecipeDef& recipe,
                        const std::map<std::string, double>& resolved)
 {
@@ -43,15 +44,18 @@ bool allInputsResolved(const RecipeDef& recipe,
     return true;
 }
 
-double computeRecipeThreat(const RecipeDef& recipe,
-                           const std::map<std::string, double>& resolved)
+// Computes the raw recipe threat (duration + sum of input threats × amounts),
+// divided by the output amount to get the per-unit threat.
+double computeRecipeThreatPerUnit(const RecipeDef& recipe,
+                                  int outputAmount,
+                                  const std::map<std::string, double>& resolved)
 {
     double threat = recipe.durationSeconds;
     for (const RecipeIngredient& input : recipe.inputs)
     {
         threat += resolved.at(input.item) * input.amount;
     }
-    return threat;
+    return threat / static_cast<double>(outputAmount);
 }
 
 }  // namespace
@@ -69,118 +73,259 @@ ThreatCostTable computeThreatCostTable(const GameConfig& config)
         ? 1.0 / config.world.scrapPerThreat
         : 0.0;
 
-    // Build lookup: output item → non-reprocessing recipes and reprocessing recipes.
-    std::map<std::string, std::vector<RecipeRef>> nonReprocessingRecipes;
+    // -------------------------------------------------------------------------
+    // Build per-item recipe lookup tables.
+    // -------------------------------------------------------------------------
+
+    // Items that have at least one non-reprocessing recipe that does NOT consume
+    // scrap — these items' scrap-consuming recipes are excluded from threat
+    // computation (REQ-THREAT-ITEM: scrap-consuming recipes are a fallback only).
+    std::set<std::string> scrapFreeItems;
+
+    // nonReprocessingRecipes: item → all eligible non-reprocessing (recipe, output)
+    // pairs. Scrap-consuming recipes are collected here temporarily; they are
+    // filtered out per item after we know which items have a scrap-free producer.
+    struct EligiblePair
+    {
+        const RecipeDef* recipe;
+        int outputAmount;
+        bool consumesScrap;
+    };
+    std::map<std::string, std::vector<EligiblePair>> nonReprocessingCandidates;
+
+    // reprocessingRecipes: item → all reprocessing-recipe refs (probability
+    // values are raw from config; we normalize them per-recipe below).
     std::map<std::string, std::vector<RecipeRef>> reprocessingRecipes;
 
     for (const RecipeDef& recipe : config.recipes.recipes)
     {
         if (recipe.building == BuildingType::ReprocessingPlant)
         {
+            // Compute the total weight across all outputs of this reprocessing recipe
+            // so we can normalize each output's probability.
+            double totalWeight = 0.0;
+            for (const RecipeOutput& out : recipe.outputs)
+            {
+                totalWeight += out.probability.value_or(1.0);
+            }
+            if (totalWeight <= 0.0)
+            {
+                continue;
+            }
+
             for (const RecipeOutput& out : recipe.outputs)
             {
                 RecipeRef ref;
                 ref.recipe = &recipe;
                 ref.outputItem = out.item;
                 ref.outputAmount = out.amount;
-                ref.probability = out.probability.value_or(1.0);
+                ref.probability = out.probability.value_or(1.0) / totalWeight;
                 reprocessingRecipes[out.item].push_back(ref);
             }
         }
         else
         {
+            // Check whether this non-reprocessing recipe consumes scrap.
+            bool consumesScrap = false;
+            for (const RecipeIngredient& input : recipe.inputs)
+            {
+                if (input.item == "scrap")
+                {
+                    consumesScrap = true;
+                    break;
+                }
+            }
+
             for (const RecipeOutput& out : recipe.outputs)
             {
-                RecipeRef ref;
-                ref.recipe = &recipe;
-                ref.outputItem = out.item;
-                ref.outputAmount = out.amount;
-                ref.probability = 1.0;
-                nonReprocessingRecipes[out.item].push_back(ref);
+                if (!consumesScrap)
+                {
+                    scrapFreeItems.insert(out.item);
+                }
+
+                EligiblePair pair;
+                pair.recipe = &recipe;
+                pair.outputAmount = out.amount;
+                pair.consumesScrap = consumesScrap;
+                nonReprocessingCandidates[out.item].push_back(pair);
             }
         }
     }
 
-    // Collect all item names that need resolving.
-    std::set<std::string> unresolved;
-    for (const std::pair<const std::string, std::vector<RecipeRef>>& entry : nonReprocessingRecipes)
+    // Filter nonReprocessingCandidates: for items that have at least one
+    // scrap-free producer, drop their scrap-consuming recipes.
+    // Build the final per-item list of (recipe, outputAmount) pairs eligible
+    // for the max-across-recipes rule (REQ-THREAT-ITEM).
+    std::map<std::string, std::vector<std::pair<const RecipeDef*, int>>> eligibleRecipes;
+    for (std::map<std::string, std::vector<EligiblePair>>::const_iterator it =
+             nonReprocessingCandidates.begin();
+         it != nonReprocessingCandidates.end();
+         ++it)
     {
-        unresolved.insert(entry.first);
-    }
-    for (const std::pair<const std::string, std::vector<RecipeRef>>& entry : reprocessingRecipes)
-    {
-        unresolved.insert(entry.first);
+        const std::string& item = it->first;
+        const std::vector<EligiblePair>& candidates = it->second;
+        bool hasScrapFree = (scrapFreeItems.find(item) != scrapFreeItems.end());
+
+        for (const EligiblePair& candidate : candidates)
+        {
+            if (candidate.consumesScrap && hasScrapFree)
+            {
+                // Scrap-consuming recipe excluded: item has a scrap-free producer.
+                continue;
+            }
+            eligibleRecipes[item].emplace_back(candidate.recipe, candidate.outputAmount);
+        }
     }
 
-    // Iteratively resolve non-reprocessing items.
-    bool progress = true;
-    while (progress)
+    // -------------------------------------------------------------------------
+    // Resolution: seed resolved map with scrap, then alternate the
+    // non-reprocessing pass and the reprocessing pass to a fixpoint.
+    // Fix (8): iterate until neither pass makes progress, rather than running
+    // the reprocessing pass once at the end.
+    // -------------------------------------------------------------------------
+
+    std::map<std::string, double>& resolved = table.itemThreat;
+    resolved["scrap"] = table.scrapThreat;
+
+    // Non-reprocessing resolution pass.
+    // Fix (9): commit an item only when EVERY eligible recipe for it is
+    // computable, not just the first one that resolves. This ensures a shallow
+    // shortcut recipe cannot undercut a deeper base recipe by resolving earlier.
+    auto runNonReprocessingPass = [&](bool requireAllRecipes) -> bool
     {
-        progress = false;
-        std::set<std::string> newlyResolved;
-        for (const std::string& item : unresolved)
+        bool progress = false;
+        std::map<std::string, double> newValues;
+
+        for (std::map<std::string, std::vector<std::pair<const RecipeDef*, int>>>::const_iterator
+                 it = eligibleRecipes.begin();
+             it != eligibleRecipes.end();
+             ++it)
         {
-            std::map<std::string, std::vector<RecipeRef>>::const_iterator it =
-                nonReprocessingRecipes.find(item);
-            if (it == nonReprocessingRecipes.end())
+            const std::string& item = it->first;
+            if (resolved.find(item) != resolved.end())
             {
                 continue;
             }
 
+            const std::vector<std::pair<const RecipeDef*, int>>& pairs = it->second;
+
+            bool allComputable = true;
             double maxThreat = -1.0;
-            for (const RecipeRef& ref : it->second)
+            for (const std::pair<const RecipeDef*, int>& pair : pairs)
             {
-                if (allInputsResolved(*ref.recipe, table.itemThreat))
+                if (!allInputsResolved(*pair.first, resolved))
                 {
-                    double threat = computeRecipeThreat(*ref.recipe, table.itemThreat);
-                    if (threat > maxThreat)
+                    allComputable = false;
+                    if (requireAllRecipes)
                     {
-                        maxThreat = threat;
+                        break;
                     }
+                    // In fallback mode: skip this recipe but continue gathering
+                    // the computable subset.
+                    continue;
+                }
+                double threat = computeRecipeThreatPerUnit(*pair.first, pair.second, resolved);
+                if (threat > maxThreat)
+                {
+                    maxThreat = threat;
                 }
             }
 
+            if (requireAllRecipes && !allComputable)
+            {
+                continue;
+            }
             if (maxThreat >= 0.0)
             {
-                table.itemThreat[item] = maxThreat;
-                newlyResolved.insert(item);
-                progress = true;
+                newValues[item] = maxThreat;
             }
         }
-        for (const std::string& item : newlyResolved)
-        {
-            unresolved.erase(item);
-        }
-    }
 
-    // Resolve reprocessing-only items.
-    for (const std::string& item : unresolved)
+        for (std::map<std::string, double>::const_iterator it = newValues.begin();
+             it != newValues.end();
+             ++it)
+        {
+            resolved[it->first] = it->second;
+            progress = true;
+        }
+        return progress;
+    };
+
+    // Reprocessing pass: resolve items produced exclusively by reprocessing.
+    // Items that also have a non-reprocessing recipe are skipped here (they are
+    // covered by the non-reprocessing pass or do not need the reprocessing path).
+    auto runReprocessingPass = [&]() -> bool
     {
-        std::map<std::string, std::vector<RecipeRef>>::const_iterator it =
-            reprocessingRecipes.find(item);
-        if (it == reprocessingRecipes.end())
+        bool progress = false;
+        for (std::map<std::string, std::vector<RecipeRef>>::const_iterator it =
+                 reprocessingRecipes.begin();
+             it != reprocessingRecipes.end();
+             ++it)
         {
-            continue;
-        }
-
-        for (const RecipeRef& ref : it->second)
-        {
-            int scrapPerCycle = 0;
-            for (const RecipeIngredient& input : ref.recipe->inputs)
+            const std::string& item = it->first;
+            if (resolved.find(item) != resolved.end())
             {
-                scrapPerCycle += input.amount;
+                continue;
+            }
+            // Reprocessing defines an item's threat only when nothing else
+            // produces it (REQ-THREAT-ITEM).
+            if (scrapFreeItems.find(item) != scrapFreeItems.end())
+            {
+                continue;
+            }
+            // Also skip items covered by eligible (non-reprocessing) recipes.
+            if (eligibleRecipes.find(item) != eligibleRecipes.end())
+            {
+                continue;
             }
 
-            double threat = (table.scrapThreat * scrapPerCycle
-                             + ref.recipe->durationSeconds) / ref.probability;
-            std::map<std::string, double>::iterator existing = table.itemThreat.find(item);
-            if (existing == table.itemThreat.end() || threat > existing->second)
+            for (const RecipeRef& ref : it->second)
             {
-                table.itemThreat[item] = threat;
+                // Sum all scrap inputs for this reprocessing recipe.
+                int scrapPerCycle = 0;
+                for (const RecipeIngredient& input : ref.recipe->inputs)
+                {
+                    scrapPerCycle += input.amount;
+                }
+
+                double threat = (table.scrapThreat * scrapPerCycle
+                                 + ref.recipe->durationSeconds) / ref.probability;
+
+                std::map<std::string, double>::iterator existing = resolved.find(item);
+                if (existing == resolved.end() || threat > existing->second)
+                {
+                    resolved[item] = threat;
+                    progress = true;
+                }
             }
         }
+        return progress;
+    };
+
+    // Main fixpoint loop: alternate non-reprocessing and reprocessing passes
+    // until neither makes any progress (fix 8).
+    bool anyProgress = true;
+    while (anyProgress)
+    {
+        anyProgress = runNonReprocessingPass(true);
+        anyProgress = runReprocessingPass() || anyProgress;
     }
 
+    // Deadlock fallback: if any items remain unresolved due to recipe cycles,
+    // fall back to committing with the max over the currently computable subset
+    // of recipes (fix 9, deadlock guard — same approach as threat_report.py's
+    // require_all_recipes=False mode).
+    anyProgress = true;
+    while (anyProgress)
+    {
+        anyProgress = runNonReprocessingPass(false);
+        anyProgress = runReprocessingPass() || anyProgress;
+    }
+
+    // Remove the sentinel scrap entry — scrapThreat is already stored on the
+    // table struct; having it in itemThreat would confuse callers iterating items.
+    resolved.erase("scrap");
+
     return table;
 }
 

src/test/ConfigLoaderTest.cpp

@@ -76,6 +76,8 @@ TEST_CASE("ConfigLoader loads the committed bin/config/ configs end-to-end", "[c
     REQUIRE(cfg.world.regions.playerBufferWidth_tiles == 10);
     REQUIRE(cfg.world.regions.enemyBufferWidth_tiles == 15);
     REQUIRE(cfg.world.expansion.columnsPerExpansion_tiles == 10);
+    REQUIRE(cfg.world.expansion.costBuildingBlocksFormula.evaluate(0) == Approx(400.0));
+    REQUIRE(cfg.world.expansion.costBuildingBlocksFormula.evaluate(1) == Approx(800.0));
     REQUIRE(cfg.world.push.bossAdvanceSeconds == Approx(60.0));
     REQUIRE(cfg.world.orbitFactor == Approx(0.8));
     REQUIRE(cfg.world.rallyOrbitRadius_tiles == Approx(5.0));
@@ -186,7 +188,7 @@ contest_zone_width_tiles = 30
 
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20
@@ -237,7 +239,7 @@ enemy_buffer_width_tiles = 15
 
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20
@@ -284,7 +286,7 @@ enemy_buffer_width_tiles = 15
 
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20

src/test/ThreatCostCalculatorTest.cpp

@@ -107,3 +107,62 @@ TEST_CASE("ThreatCostCalculator: unknown ship returns zero", "[threat]")
     double threat = calculateShipThreatCost(table, cfg, "nonexistent_ship", {});
     CHECK(threat == Approx(0.0));
 }
+
+// Fix 6: scrap-consuming recipes are a fallback only.
+// iron_ingot has a scrap-free smelter recipe, so the scrap_iron recipe must
+// be excluded. iron_ingot threat must not be inflated by the scrap path.
+TEST_CASE("ThreatCostCalculator: scrap-consuming recipe excluded when scrap-free recipe exists", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    // scrap_iron recipe: duration=1.0, 1 scrap (threat=1.0) -> 1 iron_ingot.
+    // That would give 1.0 + 1.0*1 = 2.0 per unit — but it must be excluded
+    // because the scrap-free iron_ingot smelter recipe (threat=4.0) exists.
+    // iron_ingot threat stays at 4.0.
+    CHECK(table.itemThreat.at("iron_ingot") == Approx(4.0));
+
+    // The pure reprocessing-only item (advanced_alloy) must still be resolved
+    // via the reprocessing path.
+    CHECK(table.itemThreat.count("advanced_alloy") == 1u);
+}
+
+// Fix 7: per-unit item threat divides by output amount.
+// dual_wire: assembler, 1 iron_ore -> 2 dual_wire, duration 3.0.
+// Per-unit threat = (3.0 + iron_ore(1.0)*1) / 2 = 4.0 / 2 = 2.0.
+TEST_CASE("ThreatCostCalculator: per-unit division by output amount", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    CHECK(table.itemThreat.at("dual_wire") == Approx(2.0));
+}
+
+// Fix 8: fixpoint resolution — items downstream of reprocessing-only items
+// must be resolved after the reprocessing pass re-enables the non-reprocessing
+// pass.
+// downstream_product: assembler, 1 advanced_alloy -> 1, duration 2.0.
+// advanced_alloy = 80.0 (reprocessing-only).
+// downstream_product = 2.0 + 80.0*1 = 82.0.
+TEST_CASE("ThreatCostCalculator: downstream-of-reprocessing item resolves via fixpoint", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    CHECK(table.itemThreat.at("advanced_alloy") == Approx(80.0));
+    CHECK(table.itemThreat.at("downstream_product") == Approx(82.0));
+}
+
+// Fix 9: max rule across staggered recipes — item is committed only once
+// every eligible recipe for it is computable.
+// staggered_item has two recipes:
+//   cheap:     1 iron_ore (1.0) + 1.0 s  = 2.0  (resolves early)
+//   expensive: 1 circuit_board (28.0) + 1.0 s = 29.0  (resolves later)
+// expected threat = max(2.0, 29.0) = 29.0, not 2.0.
+TEST_CASE("ThreatCostCalculator: staggered recipes committed only when all computable", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    CHECK(table.itemThreat.at("staggered_item") == Approx(29.0));
+}

src/ui/GameWorldView.cpp

@@ -39,6 +39,7 @@
 #include "FactionComponent.h"
 #include "GameOverEvent.h"
 #include "HealthComponent.h"
+#include "HqProxyComponent.h"
 #include "PositionComponent.h"
 #include "RepairBehavior.h"
 #include "SalvageScrapBehavior.h"
@@ -59,8 +60,10 @@
 #include "BuilderModeExitedEvent.h"
 #include "BlueprintModeExitedEvent.h"
 #include "BuildingBlocksChangedEvent.h"
+#include "ExpansionCostChangedEvent.h"
 #include "GameSpeedChangedEvent.h"
 #include "SchematicChoicesAvailableEvent.h"
+#include "PlayerCommandsAppliedEvent.h"
 #include "TickAdvancedEvent.h"
 
 namespace
@@ -211,6 +214,7 @@ void GameWorldView::onFrame()
         // Drain queued player commands once per frame, before the tick batch. This
         // runs even at 0x so a paused player sees placed construction sites
         // immediately, while staying deterministic (see docs/replay_design.md).
+        const bool commandsApplied = m_commandManager.hasPending();
         m_commandManager.drain();
 
         // A drained Reset reinitialized the simulation; reset the view to match.
@@ -220,6 +224,17 @@ void GameWorldView::onFrame()
             resetForNewGame();
         }
 
+        // Notify presentation widgets that queued commands were applied, so a
+        // paused player still sees the effect (e.g. a shipyard's layout preview
+        // after picking a schematic) even though no tick advances. UI-only: this
+        // does not touch the command queue or simulation, so replay recording
+        // and determinism are unaffected.
+        if (commandsApplied)
+        {
+            EventManager::getInstance()->sendEventImmediately(
+                std::make_shared<PlayerCommandsAppliedEvent>());
+        }
+
         const int ticks = m_tickDriver.advance(
             static_cast<double>(elapsed), m_gameSpeedMultiplier);
         for (int i = 0; i < ticks; ++i)
@@ -257,7 +272,9 @@ void GameWorldView::onFrame()
 
     // Apply held scroll
     {
-        const float delta = kScrollSpeedTilesPerSec
+        // Pan speed depends on where the view is centered (REQ-UI-SCROLL-SPEED).
+        const float viewCenterX = m_scrollXTiles + viewportWidthTiles() / 2.0f;
+        const float delta = panSpeedTilesPerSecondAt(viewCenterX)
             * static_cast<float>(elapsed) / 1000.0f;
         const float scrollBefore = m_scrollXTiles;
         if (m_scrollLeft)  { m_scrollXTiles -= delta; }
@@ -276,6 +293,7 @@ void GameWorldView::onFrame()
     {
         const Tick newTick      = m_sim->currentTick();
         const int  newBlocks    = m_sim->buildingBlocksStock();
+        const int  newExpCost   = m_sim->currentExpansionCost();
         const int  newBoss      = m_sim->bossWaveCounter();
         const Tick newCountdown = m_sim->bossCountdownTicks();
 
@@ -291,6 +309,12 @@ void GameWorldView::onFrame()
             EventManager::getInstance()->sendEventImmediately(
                 std::make_shared<BuildingBlocksChangedEvent>(newBlocks));
         }
+        if (newExpCost != m_lastExpansionCost)
+        {
+            m_lastExpansionCost = newExpCost;
+            EventManager::getInstance()->sendEventImmediately(
+                std::make_shared<ExpansionCostChangedEvent>(newExpCost));
+        }
         if (newBoss != m_lastBossCounter || newCountdown != m_lastBossCountdown)
         {
             m_lastBossCounter   = newBoss;
@@ -435,7 +459,7 @@ QRect GameWorldView::viewportRect() const
 
 float GameWorldView::asteroidLeftEdge() const
 {
-    float leftX = -static_cast<float>(m_config->world.regions.asteroidWidth_tiles);
+    float leftX = -static_cast<float>(m_sim->currentAsteroidWidth_tiles());
     for (const Building& b : m_sim->buildings().allBuildings())
     {
         for (const QPoint& cell : b.bodyCells)
@@ -466,6 +490,39 @@ float GameWorldView::enemyStationRightEdge() const
     return rightX;
 }
 
+namespace
+{
+    // Linearly blend from valueAt0 (for x <= x0) to valueAt1 (for x >= x1), clamped
+    // outside [x0, x1]. A zero- or negative-width band collapses to a hard step at x1.
+    float lerpClamped(float valueAt0, float valueAt1, float x0, float x1, float x)
+    {
+        if (x1 <= x0) { return x < x1 ? valueAt0 : valueAt1; }
+        const float t = std::max(0.0f, std::min(1.0f, (x - x0) / (x1 - x0)));
+        return valueAt0 + (valueAt1 - valueAt0) * t;
+    }
+}
+
+float GameWorldView::panSpeedTilesPerSecondAt(float viewCenterXTiles) const
+{
+    // Slow near the asteroid/player buffer, fast across the contest zone, with a
+    // linear ramp straddling each contest-zone boundary (REQ-UI-SCROLL-SPEED). The
+    // contest zone spans from the player buffer's right edge to the enemy stations,
+    // the latter tracked live so the ramp follows the front line as it is pushed.
+    const float slow = static_cast<float>(m_config->world.scroll.panSpeedSlow_tps);
+    const float fast = static_cast<float>(m_config->world.scroll.panSpeedFast_tps);
+    const float half = static_cast<float>(m_config->world.scroll.panRampBandWidth_tiles) / 2.0f;
+    const float leftEdge  = static_cast<float>(m_config->world.regions.playerBufferWidth_tiles);
+    const float rightEdge = enemyStationRightEdge();
+
+    // Rising ramp at the left boundary (slow -> fast) and falling ramp at the right
+    // boundary (fast -> slow); their minimum yields flat-slow outside, flat-fast in
+    // the middle, and — if the bands overlap in a narrow contest zone — a single peak
+    // below the fast speed where the two ramps cross.
+    const float leftRamp  = lerpClamped(slow, fast, leftEdge  - half, leftEdge  + half, viewCenterXTiles);
+    const float rightRamp = lerpClamped(fast, slow, rightEdge - half, rightEdge + half, viewCenterXTiles);
+    return std::min(leftRamp, rightRamp);
+}
+
 void GameWorldView::clampScroll()
 {
     const float leftBound  = asteroidLeftEdge();
@@ -549,6 +606,41 @@ BuildingId GameWorldView::siteAtTile(QPoint tile) const
 }
 
 
+std::vector<BuildingId> GameWorldView::buildingsInBox(QPoint cornerA, QPoint cornerB) const
+{
+    const int x0 = std::min(cornerA.x(), cornerB.x());
+    const int y0 = std::min(cornerA.y(), cornerB.y());
+    const int x1 = std::max(cornerA.x(), cornerB.x());
+    const int y1 = std::max(cornerA.y(), cornerB.y());
+
+    std::vector<BuildingId> ids;
+    for (const Building& b : m_sim->buildings().allBuildings())
+    {
+        for (const QPoint& cell : b.bodyCells)
+        {
+            if (cell.x() >= x0 && cell.x() <= x1
+             && cell.y() >= y0 && cell.y() <= y1)
+            {
+                ids.push_back(b.id);
+                break;
+            }
+        }
+    }
+    for (const ConstructionSite& s : m_sim->buildings().allSites())
+    {
+        for (const QPoint& cell : s.bodyCells)
+        {
+            if (cell.x() >= x0 && cell.x() <= x1
+             && cell.y() >= y0 && cell.y() <= y1)
+            {
+                ids.push_back(s.id);
+                break;
+            }
+        }
+    }
+    return ids;
+}
+
 std::optional<QVector2D> GameWorldView::entityPosition(entt::entity entity) const
 {
     if (!m_sim->admin().isValid(entity) || !m_sim->admin().hasAll<PositionComponent>(entity))
@@ -816,16 +908,19 @@ void GameWorldView::drawBuildings(QPainter& painter)
                           port.direction, bv.outline);
         }
 
-        bool selected = false;
-        for (BuildingId selId : m_selectedBuildingIds)
+        // HP bar below the HQ footprint; the HQ's HP lives on its proxy entity.
+        if (b.type == BuildingType::Hq)
         {
-            if (selId == b.id) { selected = true; break; }
-        }
-        if (selected)
-        {
-            painter.setPen(QPen(m_visuals->overlays.selectedOutline, 2));
-            painter.setBrush(Qt::NoBrush);
-            painter.drawRect(bboxRect.adjusted(-1, -1, 1, 1));
+            m_sim->admin().forEach<HqProxyComponent, FactionComponent, HealthComponent>(
+                [&](entt::entity /*e*/, const HqProxyComponent& /*hq*/,
+                    const FactionComponent& f, const HealthComponent& h)
+                {
+                    if (h.maxHp > 0.0f)
+                    {
+                        drawHpBar(painter, bboxRect.left(), bboxRect.bottom() + 1.0,
+                                  bboxRect.width(), h.hp / h.maxHp, f.isEnemy);
+                    }
+                });
         }
     }
 
@@ -850,20 +945,6 @@ void GameWorldView::drawBuildings(QPainter& painter)
         painter.setBrush(Qt::NoBrush);
         painter.drawRect(bboxRect);
 
-        bool selected = false;
-        for (BuildingId selId : m_selectedBuildingIds)
-        {
-            if (selId == s.id) { selected = true; break; }
-        }
-        if (selected)
-        {
-            painter.setOpacity(1.0);
-            painter.setPen(QPen(m_visuals->overlays.selectedOutline, 2));
-            painter.setBrush(Qt::NoBrush);
-            painter.drawRect(bboxRect.adjusted(-1, -1, 1, 1));
-            painter.setOpacity(0.5);
-        }
-
         const BuildingDef* siteDef = findBuildingDef(s.type);
         if (siteDef)
         {
@@ -908,6 +989,42 @@ void GameWorldView::drawBuildings(QPainter& painter)
         }
     }
     painter.setOpacity(1.0);
+
+    // Selection highlights are drawn last, after every building and construction
+    // site fill, so a selected building surrounded by neighbours keeps its outline:
+    // the highlight sits 1px outside the footprint (into adjacent tiles), and drawing
+    // it inline would let later-drawn neighbours overpaint it with their body fill.
+    drawSelectionHighlights(painter);
+}
+
+void GameWorldView::drawSelectionHighlights(QPainter& painter)
+{
+    painter.setPen(QPen(m_visuals->overlays.selectedOutline, 2));
+    painter.setBrush(Qt::NoBrush);
+
+    for (BuildingId selId : m_selectedBuildingIds)
+    {
+        std::optional<QPoint> anchor;
+        std::optional<QSize>  footprint;
+
+        if (const Building* b = m_sim->buildings().findBuilding(selId))
+        {
+            anchor    = b->anchor;
+            footprint = b->footprint;
+        }
+        else if (const ConstructionSite* s = m_sim->buildings().findSite(selId))
+        {
+            anchor    = s->anchor;
+            footprint = s->footprint;
+        }
+        if (!anchor.has_value() || !footprint.has_value()) { continue; }
+
+        const QPointF tl = tileToWidget(*anchor);
+        const QRectF  bboxRect(tl.x(), tl.y(),
+            footprint->width()  * static_cast<qreal>(tilePx()),
+            footprint->height() * static_cast<qreal>(tilePx()));
+        painter.drawRect(bboxRect.adjusted(-1, -1, 1, 1));
+    }
 }
 
 void GameWorldView::drawBeltItems(QPainter& painter)
@@ -985,14 +1102,8 @@ void GameWorldView::drawStations(QPainter& painter)
             // HP bar below footprint.
             if (h.maxHp > 0.0f)
             {
-                const float fraction = std::max(0.0f, h.hp / h.maxHp);
-                const qreal barH  = static_cast<qreal>(tilePx()) * 0.12;
-                const qreal barY  = bboxRect.bottom() + 1.0;
-                const qreal barW  = bboxRect.width();
-                painter.fillRect(QRectF(bboxRect.left(), barY, barW, barH),
-                                 QColor(60, 60, 60));
-                painter.fillRect(QRectF(bboxRect.left(), barY, barW * static_cast<qreal>(fraction), barH),
-                                 f.isEnemy ? QColor(200, 60, 60) : QColor(60, 200, 60));
+                drawHpBar(painter, bboxRect.left(), bboxRect.bottom() + 1.0,
+                          bboxRect.width(), h.hp / h.maxHp, f.isEnemy);
             }
         });
 }
@@ -1038,18 +1149,24 @@ void GameWorldView::drawShips(QPainter& painter)
 
             if (h.maxHp > 0.0f)
             {
-                const float fraction = std::max(0.0f, h.hp / h.maxHp);
                 const qreal barW = static_cast<qreal>(fwd) * 2.0;
-                const qreal barH = static_cast<qreal>(tilePx()) * 0.12;
                 const qreal barX = center.x() - static_cast<qreal>(fwd);
                 const qreal barY = center.y() + static_cast<qreal>(fwd) + 1.0;
-                painter.fillRect(QRectF(barX, barY, barW, barH), QColor(60, 60, 60));
-                painter.fillRect(QRectF(barX, barY, barW * static_cast<qreal>(fraction), barH),
-                                 fac.isEnemy ? QColor(200, 60, 60) : QColor(60, 200, 60));
+                drawHpBar(painter, barX, barY, barW, h.hp / h.maxHp, fac.isEnemy);
             }
         });
 }
 
+void GameWorldView::drawHpBar(QPainter& painter, qreal left, qreal top, qreal width,
+                              float fraction, bool isEnemy)
+{
+    const qreal barH = static_cast<qreal>(tilePx()) * 0.12;
+    const float clamped = std::max(0.0f, fraction);
+    painter.fillRect(QRectF(left, top, width, barH), QColor(60, 60, 60));
+    painter.fillRect(QRectF(left, top, width * static_cast<qreal>(clamped), barH),
+                     isEnemy ? QColor(200, 60, 60) : QColor(60, 200, 60));
+}
+
 void GameWorldView::drawDebugSensorRanges(QPainter& painter)
 {
     painter.setBrush(Qt::NoBrush);
@@ -1215,8 +1332,28 @@ void GameWorldView::drawOverlays(QPainter& painter)
         }
     }
 
-    // Demolish hover tint
-    if (m_demolishMode && m_demolishHoverBuildingId != kInvalidBuildingId)
+    // Demolish tint: while dragging a demolish box, tint every covered
+    // building/site (REQ-BLD-DEMOLISH-BOX); otherwise tint the hovered one.
+    if (m_demolishMode && m_boxSelecting)
+    {
+        for (BuildingId id : buildingsInBox(m_boxStartTile, m_boxCurrentTile))
+        {
+            const Building* b = m_sim->buildings().findBuilding(id);
+            if (b && b->type == BuildingType::Hq) { continue; }
+            const std::vector<QPoint>* cells = nullptr;
+            const ConstructionSite* s = nullptr;
+            if (b) { cells = &b->bodyCells; }
+            else if ((s = m_sim->buildings().findSite(id))) { cells = &s->bodyCells; }
+            if (cells)
+            {
+                for (const QPoint& cell : *cells)
+                {
+                    painter.fillRect(tileRect(cell), m_visuals->overlays.demolishTint);
+                }
+            }
+        }
+    }
+    else if (m_demolishMode && m_demolishHoverBuildingId != kInvalidBuildingId)
     {
         const Building* b = m_sim->buildings().findBuilding(m_demolishHoverBuildingId);
         if (b)
@@ -1510,24 +1647,11 @@ void GameWorldView::mousePressEvent(QMouseEvent* event)
     }
     else if (m_demolishMode)
     {
-        BuildingId hovered = buildingAtTile(tile);
-		if (hovered == kInvalidBuildingId)
-		{
-			hovered = siteAtTile(tile);
-		}
-        if (hovered != kInvalidBuildingId)
-        {
-            const Building* b = m_sim->buildings().findBuilding(hovered);
-            const bool isProtected = b && b->type == BuildingType::Hq;
-            if (!isProtected)
-            {
-                std::shared_ptr<DemolishCommand> command =
-                    std::make_shared<DemolishCommand>();
-                command->id = hovered;
-                enqueueCommand(command);
-                m_demolishHoverBuildingId = kInvalidBuildingId;
-            }
-        }
+        // Start a demolish box drag; a plain click resolves as a 1x1 box on
+        // release (REQ-BLD-DEMOLISH-CLICK, REQ-BLD-DEMOLISH-BOX).
+        m_boxSelecting   = true;
+        m_boxStartTile   = tile;
+        m_boxCurrentTile = tile;
     }
     else
     {
@@ -1615,6 +1739,7 @@ void GameWorldView::mouseMoveEvent(QMouseEvent* event)
     else if (m_demolishMode)
     {
         m_demolishHoverBuildingId = buildingAtTile(tile);
+        if (m_boxSelecting) { m_boxCurrentTile = tile; }
     }
     else if (m_boxSelecting)
     {
@@ -1636,44 +1761,33 @@ void GameWorldView::mouseReleaseEvent(QMouseEvent* event)
     {
         m_boxSelecting = false;
 
-        const int x0 = std::min(m_boxStartTile.x(), m_boxCurrentTile.x());
-        const int y0 = std::min(m_boxStartTile.y(), m_boxCurrentTile.y());
-        const int x1 = std::max(m_boxStartTile.x(), m_boxCurrentTile.x());
-        const int y1 = std::max(m_boxStartTile.y(), m_boxCurrentTile.y());
+        const std::vector<BuildingId> boxIds =
+            buildingsInBox(m_boxStartTile, m_boxCurrentTile);
 
-        std::vector<BuildingId> boxSel;
-        for (const Building& b : m_sim->buildings().allBuildings())
+        if (m_demolishMode)
         {
-            for (const QPoint& cell : b.bodyCells)
+            // Demolish every covered building/site; the HQ is protected
+            // (REQ-BLD-DEMOLISH, REQ-BLD-DEMOLISH-BOX).
+            for (BuildingId id : boxIds)
             {
-                if (cell.x() >= x0 && cell.x() <= x1
-                 && cell.y() >= y0 && cell.y() <= y1)
-                {
-                    boxSel.push_back(b.id);
-                    break;
-                }
-            }
-        }
-        for (const ConstructionSite& s : m_sim->buildings().allSites())
-        {
-            for (const QPoint& cell : s.bodyCells)
-            {
-                if (cell.x() >= x0 && cell.x() <= x1
-                 && cell.y() >= y0 && cell.y() <= y1)
-                {
-                    boxSel.push_back(s.id);
-                    break;
-                }
+                const Building* b = m_sim->buildings().findBuilding(id);
+                if (b && b->type == BuildingType::Hq) { continue; }
+                std::shared_ptr<DemolishCommand> command =
+                    std::make_shared<DemolishCommand>();
+                command->id = id;
+                enqueueCommand(command);
             }
+            m_demolishHoverBuildingId = kInvalidBuildingId;
+            return;
         }
 
         if (!(event->modifiers() & Qt::ControlModifier))
         {
-            m_selectedBuildingIds = boxSel;
+            m_selectedBuildingIds = boxIds;
         }
         else
         {
-            for (BuildingId id : boxSel)
+            for (BuildingId id : boxIds)
             {
                 bool found = false;
                 for (BuildingId sel : m_selectedBuildingIds)
@@ -1827,6 +1941,7 @@ void GameWorldView::resetForNewGame()
     m_prevNonZeroSpeed  = 1.0;
     m_lastTick          = Tick(-1);
     m_lastBlocks        = -1;
+    m_lastExpansionCost = -1;
     m_lastBossCounter   = -1;
     m_lastBossCountdown = Tick(-1);
     m_lastArtifactCount = -1;

src/ui/GameWorldView.h

@@ -115,10 +115,13 @@ private:
 
     void drawTiles(QPainter& painter);
     void drawBuildings(QPainter& painter);
+    void drawSelectionHighlights(QPainter& painter);
     void drawStations(QPainter& painter);
     void drawBeltItems(QPainter& painter);
     void drawScrap(QPainter& painter);
     void drawShips(QPainter& painter);
+    void drawHpBar(QPainter& painter, qreal left, qreal top, qreal width,
+                   float fraction, bool isEnemy);
     void drawDebugSensorRanges(QPainter& painter);
     void drawDebugTargetLines(QPainter& painter);
     void drawDebugOverlay(QPainter& painter);
@@ -137,12 +140,17 @@ private:
 
     float    asteroidLeftEdge() const;
     float    enemyStationRightEdge() const;
+    // Horizontal pan speed at a given view-center X, in tiles/s (REQ-UI-SCROLL-SPEED).
+    float    panSpeedTilesPerSecondAt(float viewCenterXTiles) const;
     void     clampScroll();
 
     bool     isValidPlacement(BuildingType type, QPoint anchor, Rotation rot) const;
     const BuildingDef* findBuildingDef(BuildingType type) const;
     BuildingId buildingAtTile(QPoint tile) const;
     BuildingId siteAtTile(QPoint tile) const;
+    // Ids of all buildings and construction sites whose footprint intersects
+    // the tile box spanned by the two (unordered) corner tiles.
+    std::vector<BuildingId> buildingsInBox(QPoint cornerA, QPoint cornerB) const;
     QVector2D  widgetToWorld(QPoint widgetPt) const;
 
     void     drawPortGlyph(QPainter& painter, QPoint bodyTile,
@@ -173,7 +181,6 @@ private:
     // Beam lifetime in game ticks so beams freeze with the simulation when
     // paused or slowed, instead of fading on wall-clock time (REQ-SHP-FIRING-BEAM).
     static constexpr Tick    kBeamLifetimeTicks      = secondsToTicks(0.3);
-    static constexpr float   kScrollSpeedTilesPerSec = 10.0f;
 
     Simulation*          m_sim;
     const GameConfig*    m_config;
@@ -226,6 +233,7 @@ private:
 
     Tick m_lastTick          = Tick(-1);
     int  m_lastBlocks        = -1;
+    int  m_lastExpansionCost = -1;
     int  m_lastBossCounter   = -1;
     Tick m_lastBossCountdown = Tick(-1);
     int  m_lastArtifactCount = -1;

src/ui/HeaderBar.cpp

@@ -8,6 +8,8 @@
 #include <QPushButton>
 #include <QSignalMapper>
 
+#include "Command.h"
+#include "CommandRequestedEvent.h"
 #include "EventManager.h"
 #include "SpeedChangeRequestedEvent.h"
 #include "Tick.h"
@@ -32,6 +34,17 @@ HeaderBar::HeaderBar(QWidget* parent)
     layout->addStretch();
     layout->addWidget(m_bossLabel);
 
+    // Asteroid expansion button, to the left of the speed buttons (REQ-UI-HEADER,
+    // REQ-UI-EXPAND-BUTTON). Caption/enabled state are set on the first
+    // ExpansionCostChangedEvent; clicking requests an ExpandAsteroidCommand.
+    m_expandButton = new QPushButton(tr("Expand"), this);
+    layout->addWidget(m_expandButton);
+    connect(m_expandButton, &QPushButton::clicked, this, []() {
+        EventManager::getInstance()->sendEventImmediately(
+            std::make_shared<CommandRequestedEvent>(
+                std::make_shared<ExpandAsteroidCommand>()));
+    });
+
     const char* labels[] = { "0x", "0.5x", "1x", "2x", "10x" };
     QSignalMapper* mapper = new QSignalMapper(this);
     for (int i = 0; i < kSpeedCount; ++i)
@@ -67,7 +80,21 @@ void HeaderBar::handleEvent(std::shared_ptr<const TickAdvancedEvent> event)
 
 void HeaderBar::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event)
 {
+    m_blocks = event->blocks;
     m_blocksLabel->setText(tr("Blocks: %1").arg(event->blocks));
+    updateExpandButton();
+}
+
+void HeaderBar::handleEvent(std::shared_ptr<const ExpansionCostChangedEvent> event)
+{
+    m_expansionCost = event->cost;
+    updateExpandButton();
+}
+
+void HeaderBar::updateExpandButton()
+{
+    m_expandButton->setText(tr("Expand: %1 Blocks").arg(m_expansionCost));
+    m_expandButton->setEnabled(m_blocks >= m_expansionCost);
 }
 
 void HeaderBar::handleEvent(std::shared_ptr<const GameSpeedChangedEvent> event)

src/ui/HeaderBar.h

@@ -8,6 +8,7 @@
 #include "BossWaveUpdatedEvent.h"
 #include "BuildingBlocksChangedEvent.h"
 #include "EventHandler.h"
+#include "ExpansionCostChangedEvent.h"
 #include "GameSpeedChangedEvent.h"
 #include "Tick.h"
 #include "TickAdvancedEvent.h"
@@ -18,6 +19,7 @@ class QPushButton;
 class HeaderBar : public QWidget,
                   public CombinedEventHandler<TickAdvancedEvent,
                                               BuildingBlocksChangedEvent,
+                                              ExpansionCostChangedEvent,
                                               GameSpeedChangedEvent,
                                               BossWaveUpdatedEvent,
                                               ArtifactCountChangedEvent>
@@ -34,16 +36,25 @@ private slots:
 private:
     void handleEvent(std::shared_ptr<const TickAdvancedEvent> event) override;
     void handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event) override;
+    void handleEvent(std::shared_ptr<const ExpansionCostChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const GameSpeedChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const BossWaveUpdatedEvent> event) override;
     void handleEvent(std::shared_ptr<const ArtifactCountChangedEvent> event) override;
 
+    // Refreshes the Expand button caption and enabled state from the current
+    // expansion cost and building block stock (REQ-UI-EXPAND-BUTTON).
+    void updateExpandButton();
+
     QLabel*                  m_timeLabel;
     QLabel*                  m_blocksLabel;
     QLabel*                  m_artifactsLabel;
     QLabel*                  m_bossLabel;
+    QPushButton*             m_expandButton;
     std::vector<QPushButton*> m_speedButtons;
 
+    int                      m_blocks        = 0;
+    int                      m_expansionCost = 0;
+
     static const double kSpeeds[];
     static const int    kSpeedCount;
 };

src/ui/SelectedBuildingPanel.cpp

@@ -33,6 +33,7 @@
 #include "ItemType.h"
 #include "LayoutDialogRequestedEvent.h"
 #include "ModulesConfig.h"
+#include "PlayerCommandsAppliedEvent.h"
 #include "RecipeSelectionDialog.h"
 #include "RecipeSelectionRequestedEvent.h"
 #include "Rotation.h"
@@ -294,38 +295,12 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
         }
         m_recipeSelectButton->show();
 
-        if (type == BuildingType::Shipyard && !recipeId.empty())
-        {
-            const ShipDef* sDef = findShipDef(recipeId);
-            if (sDef && !sDef->layout.empty())
-            {
-                ShipLayoutConfig layout;
-                if (shipLayout.has_value())
-                {
-                    layout = *shipLayout;
-                }
-                m_layoutPreview->setShipAndLayout(
-                    sDef->layout, layout, &m_config->modules.modules);
-                m_layoutPreview->show();
-                m_configureLayoutBtn->show();
-            }
-            else
-            {
-                m_layoutPreview->hide();
-                m_configureLayoutBtn->hide();
-            }
-        }
-        else
-        {
-            m_layoutPreview->hide();
-            m_configureLayoutBtn->hide();
-        }
+        updateShipyardLayoutWidgets(type, recipeId, shipLayout);
     }
     else
     {
         m_recipeSelectButton->hide();
-        m_layoutPreview->hide();
-        m_configureLayoutBtn->hide();
+        updateShipyardLayoutWidgets(type, recipeId, shipLayout);
     }
 
     // Belt "Clear" removes items from a live belt tile; a construction site has
@@ -363,32 +338,7 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
 
     if (m_singleIsSite)
     {
-        QString progress;
-        if (s->completesAt == 0)
-        {
-            progress = tr("Queued");
-        }
-        else
-        {
-            const BuildingDef* def = nullptr;
-            for (const BuildingDef& d : m_config->buildings.buildings)
-            {
-                if (d.type == s->type) { def = &d; break; }
-            }
-            if (def && def->constructionTimeSeconds > 0)
-            {
-                const Tick duration = secondsToTicks(def->constructionTimeSeconds);
-                const Tick elapsed  = m_sim->currentTick() - (s->completesAt - duration);
-                const int pct = static_cast<int>(
-                    std::max(Tick(0), std::min(duration, elapsed)) * 100 / duration);
-                progress = tr("%1% complete").arg(pct);
-            }
-            else
-            {
-                progress = tr("Building...");
-            }
-        }
-        m_buffersLabel->setText(progress);
+        refreshSiteProgress(s);
     }
     else
     {
@@ -396,6 +346,36 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
     }
 }
 
+void SelectedBuildingPanel::refreshSiteProgress(const ConstructionSite* s)
+{
+    QString progress;
+    if (s->completesAt == 0)
+    {
+        progress = tr("Queued");
+    }
+    else
+    {
+        const BuildingDef* def = nullptr;
+        for (const BuildingDef& d : m_config->buildings.buildings)
+        {
+            if (d.type == s->type) { def = &d; break; }
+        }
+        if (def && def->constructionTimeSeconds > 0)
+        {
+            const Tick duration = secondsToTicks(def->constructionTimeSeconds);
+            const Tick elapsed  = m_sim->currentTick() - (s->completesAt - duration);
+            const int pct = static_cast<int>(
+                std::max(Tick(0), std::min(duration, elapsed)) * 100 / duration);
+            progress = tr("%1% complete").arg(pct);
+        }
+        else
+        {
+            progress = tr("Building...");
+        }
+    }
+    m_buffersLabel->setText(progress);
+}
+
 void SelectedBuildingPanel::refreshBuffers(const Building* b)
 {
     const RecipeDef* recipe  = findRecipe(b);
@@ -530,15 +510,38 @@ void SelectedBuildingPanel::refreshBuffers(const Building* b)
 
     m_buffersLabel->setText(bufText);
 
-    if (b->type == BuildingType::Shipyard && shipDef && !shipDef->layout.empty())
+    // The recipe/schematic is applied via a queued command that only drains on a
+    // later frame, so the per-tick refresh must own the shipyard preview and the
+    // Configure Layout button's visibility; otherwise they stay hidden until the
+    // building is re-selected (which re-runs buildSingle).
+    updateShipyardLayoutWidgets(b->type, b->recipeId, b->shipLayout);
+}
+
+void SelectedBuildingPanel::updateShipyardLayoutWidgets(
+    BuildingType type,
+    const std::string& recipeId,
+    const std::optional<ShipLayoutConfig>& shipLayout)
+{
+    const ShipDef* shipDef = (type == BuildingType::Shipyard)
+        ? findShipDef(recipeId)
+        : nullptr;
+
+    if (shipDef && !shipDef->layout.empty())
     {
         ShipLayoutConfig layout;
-        if (b->shipLayout.has_value())
+        if (shipLayout.has_value())
         {
-            layout = *b->shipLayout;
+            layout = *shipLayout;
         }
         m_layoutPreview->setShipAndLayout(
             shipDef->layout, layout, &m_config->modules.modules);
+        m_layoutPreview->show();
+        m_configureLayoutBtn->show();
+    }
+    else
+    {
+        m_layoutPreview->hide();
+        m_configureLayoutBtn->hide();
     }
 }
 
@@ -563,6 +566,21 @@ const ShipDef* SelectedBuildingPanel::findShipDef(const std::string& id) const
 }
 
 void SelectedBuildingPanel::handleEvent(std::shared_ptr<const TickAdvancedEvent> /*event*/)
+{
+    refreshSelectionDisplay(RefreshReason::PeriodicTick);
+}
+
+void SelectedBuildingPanel::handleEvent(
+    std::shared_ptr<const PlayerCommandsAppliedEvent> /*event*/)
+{
+    // Player commands (e.g. choosing a shipyard schematic) are applied by a
+    // queued drain, not synchronously. When the game is paused no tick advances,
+    // so TickAdvancedEvent never fires; refresh here too, otherwise the panel
+    // would not reflect the change until the next tick or a re-selection.
+    refreshSelectionDisplay(RefreshReason::CommandApplied);
+}
+
+void SelectedBuildingPanel::refreshSelectionDisplay(RefreshReason reason)
 {
     if (m_selectedEntity.has_value())
     {
@@ -587,7 +605,18 @@ void SelectedBuildingPanel::handleEvent(std::shared_ptr<const TickAdvancedEvent>
     const ConstructionSite* s = m_sim->buildings().findSite(m_singleBuildingId);
     if (s)
     {
-        rebuild();
+        // A periodic tick only advances construction progress, so update just the
+        // progress label. Rebuilding every tick would hide/re-show all widgets and
+        // cancel any in-progress click on the recipe button. An applied command
+        // may have changed the site's recipe/layout, so rebuild in that case.
+        if (reason == RefreshReason::CommandApplied)
+        {
+            rebuild();
+        }
+        else
+        {
+            refreshSiteProgress(s);
+        }
         return;
     }
     buildEmpty();
@@ -647,9 +676,11 @@ void SelectedBuildingPanel::onSelectRecipeClicked()
         return;
     }
     // The emit is synchronous: MainWindow pauses the game, runs the modal
-    // selection dialog, applies the chosen recipe/schematic, and restores the
-    // speed before this returns. rebuild() then refreshes the button caption,
-    // tooltip, preview, and buffers for the new selection.
+    // selection dialog, and restores the speed before this returns. The chosen
+    // recipe/schematic is only *enqueued* as a command, though, and drains on a
+    // later frame -- so this rebuild() still sees the old recipe. The per-tick
+    // refreshBuffers() path picks up the new schematic (and shows the layout
+    // preview + Configure Layout button) once the command has been applied.
     EventManager::getInstance()->sendEventImmediately(
         std::make_shared<RecipeSelectionRequestedEvent>(m_singleBuildingId));
     rebuild();

src/ui/SelectedBuildingPanel.h

@@ -16,6 +16,7 @@
 #include "EntitySelectedEvent.h"
 #include "EventHandler.h"
 #include "GameConfig.h"
+#include "PlayerCommandsAppliedEvent.h"
 #include "RecipesConfig.h"
 #include "SelectionChangedEvent.h"
 #include "ShipLayout.h"
@@ -33,6 +34,7 @@ class QVBoxLayout;
 
 class SelectedBuildingPanel : public QWidget,
                                public CombinedEventHandler<TickAdvancedEvent,
+                                                           PlayerCommandsAppliedEvent,
                                                            EntitySelectedEvent,
                                                            SelectionChangedEvent,
                                                            DebugDrawToggledEvent>
@@ -46,6 +48,7 @@ public:
 
 private:
     void handleEvent(std::shared_ptr<const TickAdvancedEvent> event) override;
+    void handleEvent(std::shared_ptr<const PlayerCommandsAppliedEvent> event) override;
     void handleEvent(std::shared_ptr<const EntitySelectedEvent> event) override;
     void handleEvent(std::shared_ptr<const SelectionChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const DebugDrawToggledEvent> event) override;
@@ -56,7 +59,18 @@ private slots:
     void onSplitterFilterChanged();
 
 private:
+    // Why the selection display is being refreshed. A periodic tick only needs a
+    // lightweight content update (e.g. a construction site's progress label),
+    // whereas an applied player command may have changed the configuration and
+    // needs a full structural rebuild.
+    enum class RefreshReason
+    {
+        PeriodicTick,
+        CommandApplied
+    };
+
     void onSelectionChanged(const std::vector<BuildingId>& ids);
+    void refreshSelectionDisplay(RefreshReason reason);
     void rebuild();
     void hideAllWidgets();
     void clearContent();
@@ -64,6 +78,10 @@ private:
     void buildSingle(BuildingId id);
     void buildMulti(const std::vector<BuildingId>& ids);
     void refreshBuffers(const Building* b);
+    void refreshSiteProgress(const ConstructionSite* s);
+    void updateShipyardLayoutWidgets(BuildingType type,
+                                     const std::string& recipeId,
+                                     const std::optional<ShipLayoutConfig>& shipLayout);
     void buildSplitterFilters(const std::optional<BeltSystem::SplitterInfo>& info);
     const RecipeDef* findRecipe(const Building* b) const;
     const ShipDef*   findShipDef(const std::string& id) const;

tools/threat_report.py

@@ -0,0 +1,263 @@
+#!/usr/bin/env python3
+"""Report threat values, ship costs, ratios, and belt feasibility.
+
+Reads recipes.toml, ships.toml, modules.toml, and world.toml and prints:
+
+  1. Item threats — production-seconds per item unit, resolved
+     recursively over the recipe tree (REQ-THREAT-ITEM):
+       - non-reprocessing recipe: (duration + sum(input threat * qty))
+         divided by the output amount, so threat is per unit;
+       - multiple recipes: the maximum across them;
+       - recipes consuming scrap participate only if no scrap-free
+         recipe produces the item (fallback rule);
+       - reprocessing-only items: (scrap threat * scrap per cycle
+         + duration) / normalized probability (REQ-THREAT-ITEM).
+     Scrap threat is the constant 1 / world.scrap_per_threat
+     (REQ-THREAT-SCRAP).
+  2. Module contributions — material threat + production time per
+     module instance (the amount a module adds to a ship's threat).
+  3. Ship threats — hull-only and fitted with default_modules (the
+     loadout enemy waves spawn with, REQ-WAV-DEFAULT-MODULES).
+  4. Producer:consumer ratios — buildings of the input recipe needed
+     per building of the consuming recipe at 100% throughput.
+  5. Belt feasibility — input demand in items/s per building vs. the
+     single-belt cap (belt_speed_mps / tile_size_m, in items/s).
+
+NOTE: the semantics described above — per-unit division, scrap fallback
+rule, fixpoint resolution including reprocessing, and the commit-all-
+recipes max rule — are implemented in both this script and in
+src/lib/sim/ThreatCostCalculator.cpp. The two should produce identical
+values for any given config.
+
+Usage (from the repository root or anywhere else):
+
+    python dota_factory/tools/threat_report.py
+    python dota_factory/tools/threat_report.py --config-dir path/to/config
+
+By default the config directory is resolved relative to this script
+(../bin/app/data/config). Requires the 'toml' package on Python < 3.11
+(pip install --user toml); on 3.11+ the standard tomllib is used.
+"""
+
+import argparse
+import os
+import sys
+
+
+def load_toml(path):
+    try:
+        import tomllib
+        with open(path, "rb") as fh:
+            return tomllib.load(fh)
+    except ImportError:
+        import toml
+        return toml.load(path)
+
+
+def consumes_scrap(recipe):
+    return any(inp["item"] == "scrap" for inp in recipe.get("inputs", []))
+
+
+def recipe_threat_per_unit(recipe, output, item_threat):
+    threat = recipe["duration_seconds"]
+    for inp in recipe.get("inputs", []):
+        if inp["item"] not in item_threat:
+            return None
+        threat += item_threat[inp["item"]] * inp["amount"]
+    return threat / output["amount"]
+
+
+def resolve_items(recipes, scrap_threat):
+    """Return {item: threat} resolved per REQ-THREAT-ITEM."""
+    non_repro = [r for r in recipes if r["building"] != "reprocessing_plant"]
+    repro = [r for r in recipes if r["building"] == "reprocessing_plant"]
+
+    # Items with at least one scrap-free producer: their scrap-consuming
+    # recipes never participate (fallback rule).
+    scrap_free_items = set()
+    for recipe in non_repro:
+        if not consumes_scrap(recipe):
+            for output in recipe.get("outputs", []):
+                scrap_free_items.add(output["item"])
+
+    def eligible(recipe, output):
+        if consumes_scrap(recipe) and output["item"] in scrap_free_items:
+            return False
+        return True
+
+    item_threat = {"scrap": scrap_threat}
+
+    # All eligible (recipe, output) pairs per item: the max rule requires
+    # committing an item only once EVERY eligible recipe for it is
+    # computable — otherwise a shallow shortcut recipe that resolves one
+    # pass earlier than the base path would win and underprice the item.
+    recipes_per_item = {}
+    for recipe in non_repro:
+        for output in recipe.get("outputs", []):
+            if eligible(recipe, output):
+                recipes_per_item.setdefault(output["item"], []).append(
+                    (recipe, output))
+
+    def resolve_pass(require_all_recipes=True):
+        progress = False
+        best = {}
+        for item, pairs in recipes_per_item.items():
+            if item in item_threat:
+                continue
+            threats = [recipe_threat_per_unit(r, o, item_threat)
+                       for r, o in pairs]
+            if require_all_recipes and any(t is None for t in threats):
+                continue
+            threats = [t for t in threats if t is not None]
+            if threats:
+                best[item] = max(threats)
+        for item, threat in best.items():
+            item_threat[item] = threat
+            progress = True
+        return progress
+
+    def repro_pass():
+        progress = False
+        for recipe in repro:
+            scrap_per_cycle = sum(inp["amount"]
+                                  for inp in recipe.get("inputs", []))
+            total_weight = sum(out.get("probability", 1.0)
+                               for out in recipe.get("outputs", []))
+            for output in recipe.get("outputs", []):
+                # Reprocessing defines an item's threat only when nothing
+                # else produces it (REQ-THREAT-ITEM).
+                if output["item"] in item_threat:
+                    continue
+                if output["item"] in scrap_free_items:
+                    continue
+                probability = output.get("probability", 1.0) / total_weight
+                if probability <= 0.0:
+                    continue
+                item_threat[output["item"]] = (
+                    (scrap_threat * scrap_per_cycle
+                     + recipe["duration_seconds"]) / probability)
+                progress = True
+        return progress
+
+    # Iterate to a fixpoint: items downstream of reprocessing-only items
+    # (e.g. capital parts built from voidsteel) need another recipe pass
+    # after the reprocessing pass has resolved their inputs.
+    progress = True
+    while progress:
+        progress = resolve_pass()
+        progress = repro_pass() or progress
+
+    # Deadlock guard: if recipe cycles keep items waiting on each other,
+    # fall back to committing with the computable subset of recipes.
+    progress = True
+    while progress:
+        progress = resolve_pass(require_all_recipes=False)
+        progress = repro_pass() or progress
+
+    return item_threat
+
+
+def material_threat(materials, item_threat, missing):
+    total = 0.0
+    for material in materials:
+        if material["item"] in item_threat:
+            total += item_threat[material["item"]] * material["amount"]
+        else:
+            missing.add(material["item"])
+    return total
+
+
+def main():
+    default_dir = os.path.normpath(os.path.join(
+        os.path.dirname(os.path.abspath(__file__)),
+        "..", "bin", "app", "data", "config"))
+    parser = argparse.ArgumentParser(
+        description="Report threat values, ship costs, ratios, and belt"
+                    " feasibility from the config files.")
+    parser.add_argument("--config-dir", default=default_dir,
+                        help="directory containing the config toml files"
+                             " (default: %(default)s)")
+    args = parser.parse_args()
+
+    recipes = load_toml(os.path.join(args.config_dir, "recipes.toml"))["recipe"]
+    ships = load_toml(os.path.join(args.config_dir, "ships.toml"))["ship"]
+    modules = load_toml(os.path.join(args.config_dir, "modules.toml"))["module"]
+    world = load_toml(os.path.join(args.config_dir, "world.toml"))["world"]
+
+    scrap_per_threat = world.get("scrap_per_threat", 0.0)
+    scrap_threat = 1.0 / scrap_per_threat if scrap_per_threat > 0 else 0.0
+    belt_cap = world["belt_speed_mps"] / world["tile_size_m"]  # items/s
+
+    item_threat = resolve_items(recipes, scrap_threat)
+    missing = set()
+
+    print("scrap_per_threat = {}  =>  threat(scrap) = {:.2f}".format(
+        scrap_per_threat, scrap_threat))
+    print()
+
+    print("== item threats (production-seconds per unit) ==")
+    for item in sorted(item_threat):
+        if item != "scrap":
+            print("  {:24s} {:10.2f}".format(item, item_threat[item]))
+
+    print()
+    print("== module contributions (materials + production time) ==")
+    module_contribution = {}
+    for module in modules:
+        contribution = (material_threat(module["materials"], item_threat, missing)
+                        + module["production_time_seconds"])
+        module_contribution[module["id"]] = contribution
+        print("  {:24s} {:10.2f}".format(module["id"], contribution))
+
+    print()
+    print("== ship threats (hull-only / fitted with default_modules) ==")
+    for ship in ships:
+        hull = (material_threat(ship["schematic"]["materials"], item_threat, missing)
+                + ship["schematic"]["production_time_seconds"])
+        fitted = hull
+        for placed in ship.get("default_modules", []):
+            fitted += module_contribution.get(placed["type"], 0.0)
+        print("  {:16s} hull {:9.2f}   fitted {:9.2f}".format(
+            ship["id"], hull, fitted))
+
+    print()
+    print("== producer:consumer ratios (producing buildings per consuming"
+          " building) ==")
+    producers = {}  # item -> [(recipe id, items/s per building)]
+    for recipe in recipes:
+        if recipe["building"] == "reprocessing_plant":
+            continue
+        for output in recipe.get("outputs", []):
+            rate = output["amount"] / recipe["duration_seconds"]
+            producers.setdefault(output["item"], []).append((recipe["id"], rate))
+    for recipe in recipes:
+        for inp in recipe.get("inputs", []):
+            need = inp["amount"] / recipe["duration_seconds"]
+            for producer_id, supply in producers.get(inp["item"], []):
+                print("  {:20s} -> {:24s} {:6.3f}".format(
+                    producer_id, recipe["id"], need / supply))
+
+    print()
+    print("== belt feasibility (input demand items/s per building,"
+          " cap {:.2f}/s) ==".format(belt_cap))
+    over = False
+    for recipe in recipes:
+        for inp in recipe.get("inputs", []):
+            rate = inp["amount"] / recipe["duration_seconds"]
+            if rate > belt_cap:
+                print("  OVER: {} <- {}: {:.2f}/s".format(
+                    recipe["id"], inp["item"], rate))
+                over = True
+    if not over:
+        print("  all input demands under the single-belt cap")
+
+    if missing:
+        print()
+        for item in sorted(missing):
+            print("WARNING: no threat value for material '{}'".format(item))
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())