diff --git a/bin/app/data/config/modules.toml b/bin/app/data/config/modules.toml
index cbcb62a..557926b 100644
--- a/bin/app/data/config/modules.toml
+++ b/bin/app/data/config/modules.toml
@@ -47,7 +47,7 @@ attack_rate_hz = 2.0
 
 [[module]]
 id = "railgun_m"
-unlock_at_station_level = 1
+unlock_at_station_level = 2
 surface_mask = [
     "OO",
     "OO"]
@@ -64,7 +64,7 @@ attack_rate_hz = 1.5
 
 [[module]]
 id = "railgun_l"
-unlock_at_station_level = 1
+unlock_at_station_level = 6
 unlock_requires = ["railgun_m"]
 surface_mask = [
     "OOO",
@@ -101,7 +101,7 @@ 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 = 1
@@ -110,7 +110,7 @@ glyph = "Rp"
 
 [module.repair]
 repair_rate_hz = 1
-repair_amount_hp = 12
+repair_amount_hp = 9
 repair_range_m = 80
 
 # -----------------------------------------------------------------------------
@@ -119,7 +119,7 @@ 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 = 1
@@ -133,7 +133,7 @@ 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 = 1
@@ -150,7 +150,7 @@ 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 = 1
@@ -163,7 +163,7 @@ 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 = 1
@@ -179,7 +179,7 @@ added_sensor_range_m = 50
 
 [[module]]
 id = "weapon_upgrade"
-unlock_at_station_level = -1
+unlock_at_station_level = 4
 surface_mask = [
     "OO",
     "OX",
@@ -195,7 +195,7 @@ multiplied_damage = 1.2
 
 [[module]]
 id = "weapon_primer"
-unlock_at_station_level = -1
+unlock_at_station_level = 4
 surface_mask = [
     "OO",
     "OX",
@@ -211,7 +211,7 @@ multiplied_attack_rate_hz = 1.2
 
 [[module]]
 id = "weapon_stabilizer"
-unlock_at_station_level = -1
+unlock_at_station_level = 3
 surface_mask = [
     "OO",
     "OX",
@@ -234,7 +234,7 @@ multiplied_attack_rate_hz = 0.8
 
 [[module]]
 id = "drone_bay"
-unlock_at_station_level = -1
+unlock_at_station_level = 5
 surface_mask = [
     "OO",
     "OO"]
@@ -246,7 +246,7 @@ glyph = "Db"
 
 [[module]]
 id = "drone_hangar"
-unlock_at_station_level = -1
+unlock_at_station_level = 9
 surface_mask = [
     "OOOOOO",
     "OOOOOO"]
diff --git a/bin/app/data/config/recipes.toml b/bin/app/data/config/recipes.toml
index 256bb1c..cea8dcb 100644
--- a/bin/app/data/config/recipes.toml
+++ b/bin/app/data/config/recipes.toml
@@ -142,8 +142,11 @@ duration_seconds = 1.5
 
 # Depth-3 chain (ore -> ingot -> plate -> block) is the factory's
 # doubling-time knob; see the block economy rules in progression_design.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}]
diff --git a/bin/app/data/config/ships.toml b/bin/app/data/config/ships.toml
index 8349a45..4fc7883 100644
--- a/bin/app/data/config/ships.toml
+++ b/bin/app/data/config/ships.toml
@@ -84,7 +84,7 @@ sensor_range_m = 200
 # mount medium hardware.
 [[ship]]
 id = "destroyer"
-unlock_at_station_level = -1
+unlock_at_station_level = 0
 layout = [
     "OXOXO",
     "OOOOO",
@@ -120,7 +120,7 @@ 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",
@@ -158,7 +158,8 @@ 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",
@@ -179,7 +180,7 @@ materials = [{item = "battlecruiser_hull", amount = 1}]
 production_time_seconds = 5
 
 [ship.health]
-hp = 2200
+hp = 2400
 
 [ship.movement]
 speed_mps = 20
@@ -200,7 +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",
@@ -242,7 +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",
@@ -286,7 +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",
diff --git a/bin/app/data/config/world.toml b/bin/app/data/config/world.toml
index cdac851..9424e09 100644
--- a/bin/app/data/config/world.toml
+++ b/bin/app/data/config/world.toml
@@ -1,7 +1,7 @@
 [world]
 height_tiles = 40
 refund_percentage = 100
-starting_building_blocks = 1000
+starting_building_blocks = 200
 scrap_despawn_seconds = 120
 scrap_per_threat = 0.25
 tile_size_m = 10
@@ -19,7 +19,9 @@ enemy_buffer_width_tiles = 20
 
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+# Flat until the escalating cost formula lands (progression_design.md
+# action item 4).
+cost_building_blocks = 400
 
 [push]
 push_expand_columns_tiles = 10
@@ -32,10 +34,13 @@ 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 (content_design.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
diff --git a/docs/content_design.md b/docs/content_design.md
index f72b8d7..d0f4609 100644
--- a/docs/content_design.md
+++ b/docs/content_design.md
@@ -458,8 +458,8 @@ verifies it empirically. Change the anchors first, re-derive stats second.
   time) as the *prior*; per-hull HP is the empirical trim knob for
   arena results (guns are shared across many hulls, so gun changes move
   many matchups at once — hull HP moves exactly one). Current values
-  after round-4 trims: drone 60, frigate 300, destroyer 550,
-  cruiser 1500, battlecruiser 2200, battleship 6300,
+  after round-5 trims: drone 60, frigate 300, destroyer 550,
+  cruiser 1500, battlecruiser 2400, battleship 6300,
   dreadnought/carrier 24000. (The capital hulls sit well above the
   15/threat prior while their guns sit below the DPS prior — the arena
   consistently prices big ships as tanks with taxed guns.)
@@ -473,10 +473,10 @@ verifies it empirically. Change the anchors first, re-derive stats second.
 - **TTK check:** a mirror cruiser duel (51 DPS vs 2140 EHP) lasts ~42 s —
   inside the 30–60 s parity-fight band implied by the 25-ship fleet
   target. Capital mirrors run longer (~90 s), deliberately.
-- **Repair ≈ 1 HP/s per threat:** repair_tool heals 12 HP × 1 Hz at 13
-  threat (arena round 1: at 2 HP/s-per-threat the escorted team won
-  flawlessly — in-combat sustain effectively removes enemy DPS and must
-  be priced like DPS, not like HP). Salvager: collection range 60 (was
+- **Repair ≈ 0.7 HP/s per threat:** repair_tool heals 9 HP × 1 Hz at 13
+  threat (nerfed 25 → 12 → 9: in-combat sustain effectively removes
+  enemy DPS and must be priced like DPS, not like HP — the escorted
+  team held a persistent +24% at 12). Salvager: collection range 60 (was
   a nonsensical 500, beyond any sensor), cargo 20, 0.5 collections/s.
   `scrap_despawn_seconds` raised 30 → 120: a capital kill drops
   hundreds of scrap collected one per cycle, so 30 s despawned nearly
@@ -517,6 +517,21 @@ DPS (17→14, 70→52 damage), armor 640→1000, repair 25→12, station range
 still win flawlessly in round 2, the range ladder (kiting) is the next
 suspect, ahead of further DPS cuts.
 
+**Arena round 5 results (2026-07-04, with fight durations) — combat
+pass converged:** durations validate the TTK anchor: drone mirror
+22.7 s, cruiser mirror 71.2 s, battleship mirror 94.6 s, most fights
+in the 22–72 s band; the destroyers-vs-dreadnought slugfest is the
+outlier at 214 s (extreme tank vs. chip damage — acceptable for the
+extreme case). Converged: mirrors 5–10%, swarm vs cruisers +15%,
+frigates vs battleship dropped to +13% on its own (confirming the
+noise-floor read — now inside band anyway), dreadnought at +3% knife
+edge, glass vs armored +10%, two-to-one 78%, station assault stable at
+44%. Two two-round signals actioned in round 6: mixed beat
+battlecruisers again (+20%, +18%) → battlecruiser hull 2200→2400;
+repair escort held +24% twice with all frigates surviving →
+repair_amount 12→9. Everything else is frozen; further refinement
+moves to real-game playtests.
+
 **Arena round 4 results (2026-07-04) and convergence policy:** mirrors
 at 0–3%; swarm vs cruisers +7%; glass vs armored resolved at +3% for
 armored (armor 1200 confirmed after four rounds of signal). Noise
@@ -565,6 +580,65 @@ breakable). Round-3 knob changes: stabilizer range ×1.5→×1.3, and
 per-hull HP trims — battlecruiser 2700→2500, battleship 7500→7000,
 dreadnought/carrier 15500→19000.
 
+### Pacing pass — first values
+
+The mapping between station levels and boss cycles: at the intended
+push cadence (first set around cycle 2–3, roughly one per cycle from
+mid on), the destroyed set's level ℓ is reached around cycle ℓ+2. So
+level 2 ≈ the mid boundary, level 6 ≈ mid-late, levels 8–9 ≈ capitals
+with enough cycles left to ramp voidsteel production before late.
+
+**Starting set** (`unlock_at_station_level = -1`), per the starting-set
+rule (exactly enough to reach the first push): drone, frigate,
+railgun_s, salvager. Note: the building_block recipe must carry an
+explicit `-1` — building blocks appear in no schematic's materials, so
+implicit unlocking can never reach it (fixed in this pass; it was
+silently locked).
+
+**Unlock ladder** (level → unlocks; ← marks `unlock_requires`):
+
+| 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, so the first push offers a
+full dialog with no artifacts competing. Level 2 is the quartz gate:
+cruiser and railgun_m are the first schematics whose chains reach
+quartz (the shortcut recipes' outputs only become implicitly unlocked
+alongside them, so they cannot drop early).
+
+**Threat rate** `2*x + 0.15*x*x`, tuned against the factory-size curve
+with roughly 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 | — |
+
+Below the player early, crossing at the late boundary, overwhelming by
+~24 — the endless-race shape from the progression rules. Typical wave
+at x=6 (30 s gap): ~520 threat ≈ two cruisers plus escorts; boss at
+x=15: ~3800 threat ≈ two and a half dreadnoughts.
+
+**Economy**: `starting_building_blocks` 1000 → 200 (minimal block loop
++ first shipyard ≈ 150, plus beginner slack); expansion cost 200 → 400
+flat (placeholder until the escalating formula, action item 4);
+`artifact_win_count` 3 → 5 with chance `0.05*x`: ~15–18 pushes in a
+winning run offer ~7 artifact options cumulatively, so winning takes
+choosing the artifact over a schematic five times — a real decision
+each time, and the win lands in the cycle 20–24 target window.
+
 ## Balancing targets (first pass, July 2026)
 
 The six root numbers for the balancing pass. Every derived value (threat
diff --git a/docs/progression_design.md b/docs/progression_design.md
index e6f755d..6e9fb17 100644
--- a/docs/progression_design.md
+++ b/docs/progression_design.md
@@ -373,9 +373,3 @@ in `requirements.md` and the git history). Still open:
    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`.
-6. **Verify the balancing arena end condition.** Arena round 1's
-   station-assault log showed the arena "(running)" with every ship on
-   both sides destroyed — per REQ-BAL-SIM-END the station-less team
-   should have lost the moment its last ship died. Round 2 ended
-   correctly, so it may only be a log-snapshot artifact; confirm, and
-   fix the end condition if it can genuinely idle in that state.