diff --git a/src/run/crisis.ts b/src/run/crisis.ts
index c7248ca..9de1bb8 100644
--- a/src/run/crisis.ts
+++ b/src/run/crisis.ts
@@ -83,3 +83,23 @@ export function attemptNeutralize(
 export function isCrisisResolved(crisis: CrisisState): boolean {
   return crisis.resolved;
 }
+
+/** Calculate player damage per frame from active crisis */
+export function getCrisisPlayerDamage(crisis: CrisisState, deltaMs: number): number {
+  if (crisis.resolved || crisis.progress <= 0.3) return 0;
+  const deltaSec = deltaMs / 1000;
+  // Damage scales with how far above 30% threshold
+  return (crisis.progress - 0.3) * 0.7 * deltaSec;
+}
+
+/** Get visual tint for crisis overlay */
+export function getCrisisTint(crisis: CrisisState): { color: number; alpha: number } {
+  if (crisis.resolved || crisis.progress <= 0) {
+    return { color: 0x88ff88, alpha: 0 };
+  }
+  // Green toxic tint that intensifies with progress
+  return {
+    color: 0x88ff88,
+    alpha: Math.min(0.15, crisis.progress * 0.15),
+  };
+}
diff --git a/src/run/escalation.ts b/src/run/escalation.ts
new file mode 100644
index 0000000..e35f6e8
--- /dev/null
+++ b/src/run/escalation.ts
@@ -0,0 +1,48 @@
+/**
+ * Escalation Effects — how rising entropy changes the game world.
+ *
+ * GDD spec:
+ * "Entropy grows. Temperature fluctuates harder, chemical reactions become
+ *  more unstable, creatures more aggressive, NPCs more paranoid."
+ *
+ * Escalation (0.0 → 1.0) modifies:
+ * - Creature speed, aggro range, attack damage
+ * - Reaction instability (chance of unexpected side effects)
+ * - Environmental damage (toxic atmosphere)
+ */
+
+/** Multipliers and modifiers based on escalation level */
+export interface EscalationEffects {
+  /** Creature movement speed multiplier (1.0 → 1.5) */
+  creatureSpeedMultiplier: number;
+  /** Creature aggro detection range multiplier (1.0 → 1.8) */
+  creatureAggroRange: number;
+  /** Creature attack damage multiplier (1.0 → 1.6) */
+  creatureAttackMultiplier: number;
+  /** Reaction instability: chance 0–0.3 of unexpected side effects */
+  reactionInstability: number;
+  /** Environmental damage per second at current escalation */
+  environmentalDamage: number;
+}
+
+/**
+ * Calculate escalation effects from escalation level (0.0–1.0).
+ * All effects scale linearly from neutral to maximum.
+ */
+export function getEscalationEffects(escalation: number): EscalationEffects {
+  // Clamp to [0, 1]
+  const t = Math.max(0, Math.min(1, escalation));
+
+  return {
+    creatureSpeedMultiplier: lerp(1.0, 1.5, t),
+    creatureAggroRange: lerp(1.0, 1.8, t),
+    creatureAttackMultiplier: lerp(1.0, 1.6, t),
+    reactionInstability: lerp(0, 0.3, t),
+    environmentalDamage: t > 0.6 ? lerp(0, 0.5, (t - 0.6) / 0.4) : 0,
+  };
+}
+
+/** Linear interpolation */
+function lerp(a: number, b: number, t: number): number {
+  return a + (b - a) * t;
+}
diff --git a/src/scenes/GameScene.ts b/src/scenes/GameScene.ts
index 51d80b1..1531d06 100644
--- a/src/scenes/GameScene.ts
+++ b/src/scenes/GameScene.ts
@@ -52,9 +52,12 @@ import {
   createCrisisState,
   applyCrisisDamage,
   attemptNeutralize,
+  getCrisisPlayerDamage,
+  getCrisisTint,
   CHEMICAL_PLAGUE,
   type CrisisState,
 } from '../run/crisis';
+import { getEscalationEffects } from '../run/escalation';
 
 export class GameScene extends Phaser.Scene {
   private gameWorld!: GameWorld;
@@ -396,14 +399,26 @@ export class GameScene extends Phaser.Scene {
     // 9g. Crisis damage (if active)
     if (this.crisisState?.active) {
       applyCrisisDamage(this.crisisState, delta);
-      // Crisis damages player slowly
-      if (this.crisisState.progress > 0.3) {
-        const crisisDmg = this.crisisState.progress * 0.5 * (delta / 1000);
+      const crisisDmg = getCrisisPlayerDamage(this.crisisState, delta);
+      if (crisisDmg > 0) {
         Health.current[this.playerEid] = Math.max(
           0,
           (Health.current[this.playerEid] ?? 0) - crisisDmg,
         );
       }
+      // Update crisis visual tint
+      const tint = getCrisisTint(this.crisisState);
+      this.crisisOverlay.setFillStyle(tint.color, tint.alpha);
+    }
+
+    // 9h. Environmental damage from high escalation
+    const escalationFx = getEscalationEffects(this.runState.escalation);
+    if (escalationFx.environmentalDamage > 0) {
+      const envDmg = escalationFx.environmentalDamage * (delta / 1000);
+      Health.current[this.playerEid] = Math.max(
+        0,
+        (Health.current[this.playerEid] ?? 0) - envDmg,
+      );
     }
 
     // 10. Health / death
@@ -493,8 +508,14 @@ export class GameScene extends Phaser.Scene {
     // Update phase indicator
     const phaseName = RUN_PHASE_NAMES_RU[this.runState.phase];
     const escalationPct = Math.round(this.runState.escalation * 100);
-    const crisisInfo = this.crisisState?.active ? ` | ЧУМА: ${Math.round(this.crisisState.progress * 100)}%` : '';
-    this.phaseText.setText(`${phaseName} | Эскалация: ${escalationPct}%${crisisInfo}`);
+    const crisisInfo = this.crisisState?.active
+      ? ` | ☠ ЧУМА: ${Math.round(this.crisisState.progress * 100)}%`
+      : this.runState.crisisResolved ? ' | ✓ Чума нейтрализована' : '';
+    const escFx = getEscalationEffects(this.runState.escalation);
+    const speedInfo = escFx.creatureSpeedMultiplier > 1.05
+      ? ` | Агрессия: ×${escFx.creatureAttackMultiplier.toFixed(1)}`
+      : '';
+    this.phaseText.setText(`${phaseName} | Энтропия: ${escalationPct}%${speedInfo}${crisisInfo}`);
 
     // Color phase text based on danger
     if (this.runState.phase >= RunPhase.Crisis) {
diff --git a/tests/escalation.test.ts b/tests/escalation.test.ts
new file mode 100644
index 0000000..83bb15c
--- /dev/null
+++ b/tests/escalation.test.ts
@@ -0,0 +1,147 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import type { RunState } from '../src/run/types';
+import { RunPhase, ESCALATION_RATE } from '../src/run/types';
+import { createRunState, advancePhase, updateEscalation } from '../src/run/state';
+import {
+  getEscalationEffects,
+  type EscalationEffects,
+} from '../src/run/escalation';
+import {
+  createCrisisState,
+  applyCrisisDamage,
+  attemptNeutralize,
+  isCrisisResolved,
+  getCrisisPlayerDamage,
+  getCrisisTint,
+  CHEMICAL_PLAGUE,
+} from '../src/run/crisis';
+
+// ─── Escalation Effects ──────────────────────────────────────────
+
+describe('Escalation Effects', () => {
+  it('at 0 escalation, all multipliers are 1.0', () => {
+    const fx = getEscalationEffects(0);
+    expect(fx.creatureSpeedMultiplier).toBe(1.0);
+    expect(fx.creatureAggroRange).toBe(1.0);
+    expect(fx.creatureAttackMultiplier).toBe(1.0);
+    expect(fx.reactionInstability).toBe(0);
+    expect(fx.environmentalDamage).toBe(0);
+  });
+
+  it('at 0.5 escalation, effects are moderate', () => {
+    const fx = getEscalationEffects(0.5);
+    expect(fx.creatureSpeedMultiplier).toBeGreaterThan(1.0);
+    expect(fx.creatureSpeedMultiplier).toBeLessThan(2.0);
+    expect(fx.creatureAggroRange).toBeGreaterThan(1.0);
+    expect(fx.creatureAttackMultiplier).toBeGreaterThan(1.0);
+    expect(fx.reactionInstability).toBeGreaterThan(0);
+  });
+
+  it('at 1.0 escalation, effects are maximal', () => {
+    const fx = getEscalationEffects(1.0);
+    expect(fx.creatureSpeedMultiplier).toBe(1.5);
+    expect(fx.creatureAggroRange).toBe(1.8);
+    expect(fx.creatureAttackMultiplier).toBe(1.6);
+    expect(fx.reactionInstability).toBe(0.3);
+    expect(fx.environmentalDamage).toBeGreaterThan(0);
+  });
+
+  it('escalation clamps values correctly', () => {
+    const fx = getEscalationEffects(2.0); // over max
+    expect(fx.creatureSpeedMultiplier).toBe(1.5);
+
+    const fxNeg = getEscalationEffects(-1.0); // under min
+    expect(fxNeg.creatureSpeedMultiplier).toBe(1.0);
+  });
+});
+
+// ─── Crisis Damage ───────────────────────────────────────────────
+
+describe('Crisis Player Damage', () => {
+  it('no damage below 30% progress', () => {
+    const crisis = createCrisisState(CHEMICAL_PLAGUE);
+    crisis.progress = 0.2;
+    expect(getCrisisPlayerDamage(crisis, 1000)).toBe(0);
+  });
+
+  it('damage increases with progress above 30%', () => {
+    const crisis = createCrisisState(CHEMICAL_PLAGUE);
+    crisis.progress = 0.5;
+    const dmg = getCrisisPlayerDamage(crisis, 1000);
+    expect(dmg).toBeGreaterThan(0);
+  });
+
+  it('damage scales with delta time', () => {
+    const crisis = createCrisisState(CHEMICAL_PLAGUE);
+    crisis.progress = 0.8;
+    const dmg1 = getCrisisPlayerDamage(crisis, 1000);
+    const dmg2 = getCrisisPlayerDamage(crisis, 2000);
+    expect(dmg2).toBeCloseTo(dmg1 * 2, 1);
+  });
+
+  it('no damage when resolved', () => {
+    const crisis = createCrisisState(CHEMICAL_PLAGUE);
+    crisis.progress = 0.8;
+    crisis.resolved = true;
+    expect(getCrisisPlayerDamage(crisis, 1000)).toBe(0);
+  });
+});
+
+describe('Crisis Visual Tint', () => {
+  it('returns no tint at 0 progress', () => {
+    const crisis = createCrisisState(CHEMICAL_PLAGUE);
+    crisis.progress = 0;
+    const tint = getCrisisTint(crisis);
+    expect(tint.alpha).toBe(0);
+  });
+
+  it('returns tint at high progress', () => {
+    const crisis = createCrisisState(CHEMICAL_PLAGUE);
+    crisis.progress = 0.8;
+    const tint = getCrisisTint(crisis);
+    expect(tint.alpha).toBeGreaterThan(0);
+    expect(tint.color).toBeDefined();
+  });
+
+  it('returns no tint when resolved', () => {
+    const crisis = createCrisisState(CHEMICAL_PLAGUE);
+    crisis.progress = 0.8;
+    crisis.resolved = true;
+    const tint = getCrisisTint(crisis);
+    expect(tint.alpha).toBe(0);
+  });
+});
+
+// ─── Escalation-Phase Integration ────────────────────────────────
+
+describe('Escalation Integration', () => {
+  let state: RunState;
+
+  beforeEach(() => {
+    state = createRunState(1, 'alchemist');
+    state.phase = RunPhase.Escalation;
+  });
+
+  it('escalation grows steadily over time', () => {
+    // Simulate 30 seconds
+    for (let i = 0; i < 30; i++) {
+      updateEscalation(state, 1000);
+    }
+    expect(state.escalation).toBeCloseTo(ESCALATION_RATE * 30, 2);
+  });
+
+  it('effects scale linearly with escalation', () => {
+    updateEscalation(state, 100_000); // ~100 seconds
+    const fx = getEscalationEffects(state.escalation);
+    expect(fx.creatureSpeedMultiplier).toBeGreaterThan(1.0);
+    expect(fx.creatureAggroRange).toBeGreaterThan(1.0);
+  });
+
+  it('full escalation cycle reaches crisis threshold', () => {
+    // Simulate until threshold
+    for (let i = 0; i < 200; i++) {
+      updateEscalation(state, 1000);
+    }
+    expect(state.escalation).toBeGreaterThanOrEqual(CHEMICAL_PLAGUE.triggerThreshold);
+  });
+});