diff --git a/src/app/main.cpp b/src/app/main.cpp
index 4b322a0..37d11a9 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -9,7 +9,6 @@
 #include "LogManager.h"
 #include "MainWindow.h"
 #include "Simulation.h"
-#include "VisualsLoader.h"
 
 int main(int argc, char *argv[])
 {
@@ -33,10 +32,9 @@ int main(int argc, char *argv[])
 	}
 
 	GameConfig config = ConfigLoader::loadFromDirectory(DOTA_FACTORY_CONFIG_DIR);
-	VisualsConfig visuals = VisualsLoader::load(std::string(DOTA_FACTORY_CONFIG_DIR) + "/visuals.toml");
-	std::unique_ptr<Simulation> sim = std::make_unique<Simulation>(config);
+	std::unique_ptr<Simulation> sim = std::make_unique<Simulation>(std::move(config));
 
-	MainWindow window(sim.get(), &config, &visuals);
+	MainWindow window(sim.get(), std::string(DOTA_FACTORY_CONFIG_DIR));
 	window.show();
 
 	const int ret = application.exec();
diff --git a/src/lib/config/GameConfig.h b/src/lib/config/GameConfig.h
index 5a22c30..a37e1cf 100644
--- a/src/lib/config/GameConfig.h
+++ b/src/lib/config/GameConfig.h
@@ -6,8 +6,8 @@
 #include "ShipsConfig.h"
 #include "StationsConfig.h"
 
-// Aggregate of all five simulation config files, loaded once at startup and
-// immutable for the rest of the game. See architecture.md "Config Loading".
+// Aggregate of all five simulation config files. Loaded at startup and reloaded
+// from disk on each game restart (REQ-CFG-RELOAD). See architecture.md "Config Loading".
 struct GameConfig
 {
     WorldConfig world;
diff --git a/src/lib/sim/Simulation.cpp b/src/lib/sim/Simulation.cpp
index 2486656..f561ca2 100644
--- a/src/lib/sim/Simulation.cpp
+++ b/src/lib/sim/Simulation.cpp
@@ -9,23 +9,23 @@
 #include "SurfaceMask.h"
 #include "WaveSystem.h"
 
-Simulation::Simulation(const GameConfig& config, unsigned int seed)
-    : m_config(config)
+Simulation::Simulation(GameConfig config, unsigned int seed)
+    : m_config(std::move(config))
     , m_rng(seed)
     , m_currentTick(0)
     , m_nextId(1)
-    , m_buildingBlocksStock(config.world.startingBuildingBlocks)
+    , m_buildingBlocksStock(m_config.world.startingBuildingBlocks)
     , m_gameOver(false)
     , m_hqId(kInvalidEntityId)
     , m_playerStation1Id(kInvalidEntityId)
     , m_playerStation2Id(kInvalidEntityId)
-    , m_beltSystem(config.world.beltSpeedTilesPerSecond)
+    , m_beltSystem(m_config.world.beltSpeedTilesPerSecond)
 {
     m_currentEnemyStationIds[0] = kInvalidEntityId;
     m_currentEnemyStationIds[1] = kInvalidEntityId;
 
     m_buildingSystem = std::make_unique<BuildingSystem>(
-        config,
+        m_config,
         m_beltSystem,
         [this]() { return allocateId(); },
         [this](int amount) { m_buildingBlocksStock += amount; },
@@ -39,13 +39,13 @@ Simulation::Simulation(const GameConfig& config, unsigned int seed)
             m_shipSystem->spawn(id, it->second.level, pos, /*isEnemy=*/false);
         },
         m_rng);
-    m_shipSystem  = std::make_unique<ShipSystem>(config, [this]() { return allocateId(); });
+    m_shipSystem  = std::make_unique<ShipSystem>(m_config, [this]() { return allocateId(); });
     m_scrapSystem = std::make_unique<ScrapSystem>([this]() { return allocateId(); });
-    m_waveSystem  = std::make_unique<WaveSystem>(config, m_rng);
-    m_combatSystem = std::make_unique<CombatSystem>(config);
+    m_waveSystem  = std::make_unique<WaveSystem>(m_config, m_rng);
+    m_combatSystem = std::make_unique<CombatSystem>(m_config);
 
     // Initialize blueprint unlock state.
-    for (const ShipDef& def : config.ships.ships)
+    for (const ShipDef& def : m_config.ships.ships)
     {
         BlueprintState state;
         state.unlocked = def.availableFromStart;
@@ -58,6 +58,17 @@ Simulation::Simulation(const GameConfig& config, unsigned int seed)
 
 Simulation::~Simulation() = default;
 
+const GameConfig& Simulation::config() const
+{
+    return m_config;
+}
+
+void Simulation::reset(GameConfig newConfig, unsigned int seed)
+{
+    m_config = std::move(newConfig);
+    reset(seed);
+}
+
 void Simulation::reset(unsigned int seed)
 {
     m_rng.seed(seed);
diff --git a/src/lib/sim/Simulation.h b/src/lib/sim/Simulation.h
index 828b61c..bd21a27 100644
--- a/src/lib/sim/Simulation.h
+++ b/src/lib/sim/Simulation.h
@@ -26,12 +26,17 @@ class WaveSystem;
 class Simulation
 {
 public:
-    explicit Simulation(const GameConfig& config, unsigned int seed = 0);
+    explicit Simulation(GameConfig config, unsigned int seed = 0);
     ~Simulation();
 
+    const GameConfig& config() const;
+
     // Reinitializes all simulation state as if constructed fresh.
     void reset(unsigned int seed = 0);
 
+    // Reloads config then reinitializes all simulation state.
+    void reset(GameConfig newConfig, unsigned int seed = 0);
+
     // Advances the simulation by one tick. Tick order per architecture.md §Tick Order.
     void tick();
 
@@ -83,7 +88,7 @@ private:
     // Award a random blueprint drop (REQ-DEF-BLUEPRINT-DROP) and emit the event.
     void awardBlueprintDrop();
 
-    const GameConfig& m_config;
+    GameConfig m_config;
     std::mt19937 m_rng;
 
     Tick     m_currentTick;
diff --git a/src/ui/MainWindow.cpp b/src/ui/MainWindow.cpp
index 7a608cc..2af7d88 100644
--- a/src/ui/MainWindow.cpp
+++ b/src/ui/MainWindow.cpp
@@ -8,15 +8,18 @@
 #include <QVBoxLayout>
 
 #include "BuildButtonGrid.h"
+#include "ConfigLoader.h"
 #include "GameWorldView.h"
 #include "HeaderBar.h"
 #include "SelectedBuildingPanel.h"
 #include "Simulation.h"
 #include "Tick.h"
+#include "VisualsLoader.h"
 
-MainWindow::MainWindow(Simulation* sim, const GameConfig* config,
-                       const VisualsConfig* visuals, QWidget* parent)
+MainWindow::MainWindow(Simulation* sim, const std::string& configDir, QWidget* parent)
     : QWidget(parent)
+    , m_configDir(configDir)
+    , m_visuals(VisualsLoader::load(configDir + "/visuals.toml"))
     , m_sim(sim)
 {
     setWindowTitle("Dota Factory");
@@ -24,15 +27,15 @@ MainWindow::MainWindow(Simulation* sim, const GameConfig* config,
 
     m_headerBar = new HeaderBar(this);
 
-    m_gameWorldView = new GameWorldView(sim, config, visuals, this);
+    m_gameWorldView = new GameWorldView(sim, &sim->config(), &m_visuals, this);
 
     m_bottomPanel = new QWidget(this);
     QHBoxLayout* bottomLayout = new QHBoxLayout(m_bottomPanel);
     bottomLayout->setContentsMargins(0, 0, 0, 0);
     bottomLayout->setSpacing(0);
 
-    m_selectedBuildingPanel = new SelectedBuildingPanel(sim, config, m_bottomPanel);
-    m_buildButtonGrid       = new BuildButtonGrid(config, m_bottomPanel);
+    m_selectedBuildingPanel = new SelectedBuildingPanel(sim, &sim->config(), m_bottomPanel);
+    m_buildButtonGrid       = new BuildButtonGrid(&sim->config(), m_bottomPanel);
 
     bottomLayout->addWidget(m_selectedBuildingPanel, 1);
     bottomLayout->addWidget(m_buildButtonGrid,       1);
@@ -128,7 +131,20 @@ void MainWindow::onEscapeMenuRequested()
     QAbstractButton* clicked = box.clickedButton();
     if (clicked == restartBtn)
     {
-        m_sim->reset();
+        try
+        {
+            GameConfig newConfig = ConfigLoader::loadFromDirectory(m_configDir);
+            VisualsConfig newVisuals = VisualsLoader::load(m_configDir + "/visuals.toml");
+            m_visuals = std::move(newVisuals);
+            m_sim->reset(std::move(newConfig));
+        }
+        catch (const std::exception& e)
+        {
+            QMessageBox::critical(this, "Config Error",
+                QString("Failed to reload config:\n%1").arg(e.what()));
+            m_gameWorldView->setGameSpeed(prevSpeed);
+            return;
+        }
         m_gameWorldView->resetForNewGame();
     }
     else if (clicked == quitBtn)
@@ -159,7 +175,19 @@ void MainWindow::onGameOver()
 
     if (box.clickedButton() == restartBtn)
     {
-        m_sim->reset();
+        try
+        {
+            GameConfig newConfig = ConfigLoader::loadFromDirectory(m_configDir);
+            VisualsConfig newVisuals = VisualsLoader::load(m_configDir + "/visuals.toml");
+            m_visuals = std::move(newVisuals);
+            m_sim->reset(std::move(newConfig));
+        }
+        catch (const std::exception& e)
+        {
+            QMessageBox::critical(this, "Config Error",
+                QString("Failed to reload config:\n%1").arg(e.what()));
+            return;
+        }
         m_gameWorldView->resetForNewGame();
     }
     else
diff --git a/src/ui/MainWindow.h b/src/ui/MainWindow.h
index 563c7fe..77df407 100644
--- a/src/ui/MainWindow.h
+++ b/src/ui/MainWindow.h
@@ -1,8 +1,9 @@
 #pragma once
 
+#include <string>
+
 #include <QWidget>
 
-#include "GameConfig.h"
 #include "Tick.h"
 #include "VisualsConfig.h"
 
@@ -18,8 +19,7 @@ class MainWindow : public QWidget
     Q_OBJECT
 
 public:
-    MainWindow(Simulation* sim, const GameConfig* config,
-               const VisualsConfig* visuals, QWidget* parent = nullptr);
+    MainWindow(Simulation* sim, const std::string& configDir, QWidget* parent = nullptr);
 
 protected:
     void resizeEvent(QResizeEvent* event) override;
@@ -32,6 +32,8 @@ private slots:
 private:
     void layoutPanels();
 
+    std::string            m_configDir;
+    VisualsConfig          m_visuals;
     Simulation*            m_sim;
     GameWorldView*         m_gameWorldView;
     HeaderBar*             m_headerBar;