diff --git a/game/README.md b/game/README.md
index bb9ef12..5ca6960 100644
--- a/game/README.md
+++ b/game/README.md
@@ -46,5 +46,7 @@ metadata is retained; reserved ledges and glide lifts do not become solid surfac
 Walk with A/D or left/right arrows, or a gamepad stick/D-pad. Holding the same
 direction for 0.4 seconds accelerates from 150.5 to 258 px/s (3.5 to 6 m/s).
 F2 shows speed, hold time, position and the 28×76 player body. The hero currently
-uses the idle atlas pose; animation switching is delivered by #31. Jump, slopes
-and ladders follow in their own issues.
+uses the idle atlas pose on the ground; full animation switching is delivered by #31.
+Space/K or gamepad A/Cross jumps, with about 52px tap height and 96px held height,
+0.1s coyote time and 0.12s buffering. Landing uses the drawn landing pose; falls
+of at least 152px use the four-frame hard landing. Slopes and ladders follow separately.
diff --git a/game/src/player/body.ts b/game/src/player/body.ts
index 4b03a29..a94e933 100644
--- a/game/src/player/body.ts
+++ b/game/src/player/body.ts
@@ -1,4 +1,5 @@
 import type { Box, Geometry } from '../stage/collision';
+import { GRAVITY } from './jump';
 export const BODY_WIDTH = 28;
 export const BODY_HEIGHT = 76;
 export interface Body { x: number; y: number; vx: number; vy: number; grounded: boolean }
@@ -19,7 +20,7 @@ export function stepBody(body: Body, geometry: Geometry[], dt: number) {
       body.x = wall.x + wall.w + 14; body.vx = 0;
     }
   }
-  body.vy = Math.min(900, body.vy + 1200 * dt);
+  body.vy = Math.min(900, body.vy + GRAVITY * dt);
   let nextY = body.y + body.vy * dt;
   body.grounded = false;
   for (const world of geometry) {
diff --git a/game/src/player/jump.test.ts b/game/src/player/jump.test.ts
new file mode 100644
index 0000000..5abc28b
--- /dev/null
+++ b/game/src/player/jump.test.ts
@@ -0,0 +1,52 @@
+import { describe, expect, it } from 'vitest';
+import { jump, jumpState, landing } from './jump';
+import { stepBody, type Body } from './body';
+import type { Geometry } from '../stage/collision';
+const floor: Geometry = { walk: [[[0, 500], [1000, 500]]], slide: [], oneWay: [], solid: [],
+  climb: [], noGo: [], hazard: [], interact: [], spawn: [], ledge: [], glideLift: [] };
+const body = (): Body => ({ x: 100, y: 500, vx: 0, vy: 0, grounded: true });
+const dt = 1 / 120;
+
+describe('controlled jump', () => {
+  const height = (releaseAt: number) => {
+    const b = body(), state = jumpState(b.y);
+    for (let i = 0; i < 160; i++) {
+      jump(b, state, i < releaseAt, dt);
+      const grounded = b.grounded;
+      stepBody(b, [floor], dt); landing(b, state, grounded, dt);
+    }
+    expect(b.y).toBe(500); expect(b.grounded).toBe(true);
+    return state.height;
+  };
+  it('gives about 52px on tap and 96px held, with intermediate control', () => {
+    expect(height(2)).toBeCloseTo(52, -1);
+    expect(height(120)).toBeCloseTo(96, 0);
+    expect(height(25)).toBeGreaterThan(65); expect(height(25)).toBeLessThan(96);
+  });
+  it('allows coyote jumps for 0.1s but rejects later presses', () => {
+    for (const [wait, accepted] of [[9, true], [14, false]] as const) {
+      const b = body(), state = jumpState(b.y); jump(b, state, false, dt); b.grounded = false;
+      for (let i = 0; i < wait; i++) jump(b, state, false, dt);
+      jump(b, state, true, dt); expect(b.vy < 0).toBe(accepted);
+    }
+  });
+  it('buffers a press just before landing, expires it, and never repeats a held jump', () => {
+    for (const [wait, accepted] of [[8, true], [16, false]] as const) {
+      const b = { ...body(), grounded: false }, state = jumpState(500);
+      jump(b, state, true, dt);
+      for (let i = 0; i < wait; i++) jump(b, state, true, dt);
+      b.grounded = true; jump(b, state, true, dt); expect(b.vy < 0).toBe(accepted);
+    }
+    const b = body(), state = jumpState(500); let launches = 0;
+    for (let i = 0; i < 240; i++) {
+      jump(b, state, true, dt); if (b.vy === -485) launches++;
+      const grounded = b.grounded; stepBody(b, [floor], dt); landing(b, state, grounded, dt);
+    }
+    expect(launches).toBe(1);
+  });
+  it('selects the hard landing after a fall of at least two body heights', () => {
+    const b = body(), state = jumpState(300);
+    landing(b, state, false, dt); expect(state.hard).toBe(true); expect(state.landing).toBe(4 / 12);
+    state.peak = 450; landing(b, state, false, dt); expect(state.hard).toBe(false);
+  });
+});
diff --git a/game/src/player/jump.ts b/game/src/player/jump.ts
new file mode 100644
index 0000000..834b6e0
--- /dev/null
+++ b/game/src/player/jump.ts
@@ -0,0 +1,40 @@
+import type { Body } from './body';
+export const COYOTE = 0.1;
+export const BUFFER = 0.12;
+export const GRAVITY = 1200;
+export const TAP_HEIGHT = 52;
+export const HOLD_HEIGHT = 96;
+export const JUMP_SPEED = 485; // Semi-implicit 120Hz integration reaches about 96px.
+export interface Jump {
+  coyote: number; buffer: number; wasDown: boolean; active: boolean;
+  origin: number; peak: number; height: number; landing: number; hard: boolean;
+}
+export const jumpState = (y: number): Jump => ({ coyote: 0, buffer: 0, wasDown: false, active: false,
+  origin: y, peak: y, height: 0, landing: 0, hard: false });
+
+export function jump(body: Body, state: Jump, down: boolean, dt: number) {
+  state.coyote = body.grounded ? COYOTE : Math.max(0, state.coyote - dt);
+  state.buffer = down && !state.wasDown ? BUFFER : Math.max(0, state.buffer - dt);
+  state.wasDown = down;
+  if (state.buffer > 1e-9 && state.coyote > 1e-9) {
+    body.vy = -JUMP_SPEED; body.grounded = false;
+    state.coyote = 0; state.buffer = 0; state.active = true;
+    state.origin = body.y; state.peak = body.y; state.height = 0; state.landing = 0;
+  }
+  if (!down && state.active && body.vy < 0) {
+    // Early releases share a 52px minimum rise; later releases stop at their current height.
+    const remainingRise = Math.max(0, TAP_HEIGHT - (state.origin - body.y));
+    body.vy = Math.max(body.vy, -Math.sqrt(2 * GRAVITY * remainingRise));
+  }
+}
+
+export function landing(body: Body, state: Jump, wasGrounded: boolean, dt: number) {
+  state.landing = Math.max(0, state.landing - dt);
+  state.peak = Math.min(state.peak, body.y);
+  if (state.active) state.height = Math.max(state.height, state.origin - body.y);
+  if (!wasGrounded && body.grounded) {
+    state.hard = body.y - state.peak >= 152; // Two body heights; tune with the route playtest.
+    state.landing = state.hard ? 4 / 12 : 2 / 12;
+    state.active = false; state.peak = body.y;
+  }
+}
diff --git a/game/src/player/player.ts b/game/src/player/player.ts
index 3f560f6..a7ae3d7 100644
--- a/game/src/player/player.ts
+++ b/game/src/player/player.ts
@@ -2,6 +2,7 @@ import Phaser from 'phaser';
 import type { CollisionChunk } from '../stage/collision';
 import { BODY_HEIGHT, BODY_WIDTH, overlaps, stepBody, type Body } from './body';
 import { horizontal, move, movement } from './movement';
+import { jump, jumpState, landing } from './jump';
 
 export class Player {
   readonly body: Body;
@@ -13,11 +14,13 @@ export class Player {
   private showDebug = false;
   private lastSpeed = 0;
   private spawn;
+  private air;
   constructor(private scene: Phaser.Scene, private chunks: CollisionChunk[]) {
     this.spawn = chunks.flatMap(c => c.world.spawn).find(p => p.kind === 'player') ?? { x: 120, y: 461 };
     this.body = { x: this.spawn.x, y: this.spawn.y, vx: 0, vy: 0, grounded: true };
+    this.air = jumpState(this.body.y);
     this.sprite = scene.add.sprite(this.body.x, this.body.y, 'hero-move', 'idle-00').setOrigin(0.5, 1).setDepth(100);
-    this.keys = scene.input.keyboard!.addKeys('A,D,LEFT,RIGHT') as Record<string, Phaser.Input.Keyboard.Key>;
+    this.keys = scene.input.keyboard!.addKeys('A,D,LEFT,RIGHT,SPACE,K') as Record<string, Phaser.Input.Keyboard.Key>;
     this.debug = scene.add.graphics().setDepth(10001);
     this.label = scene.add.text(20, 80, '', { fontFamily: 'monospace', fontSize: '18px', backgroundColor: '#17242d' })
       .setScrollFactor(0).setDepth(10002).setVisible(false);
@@ -29,24 +32,34 @@ export class Player {
     const pad = this.scene.input.gamepad?.getAll().find(p => p.connected);
     const axis = horizontal(this.keys.A.isDown || this.keys.LEFT.isDown, this.keys.D.isDown || this.keys.RIGHT.isDown,
       pad?.leftStick.x, pad?.left, pad?.right);
+    const jumpDown = this.keys.SPACE.isDown || this.keys.K.isDown || !!pad?.A;
     // Substeps keep wall and floor contacts stable during slow rendered frames.
     let remaining = Math.min(milliseconds / 1000, 0.1);
     while (remaining > 1e-9) {
       const dt = Math.min(remaining, 1 / 120);
       move(this.motion, axis, dt); this.body.vx = this.motion.vx;
+      jump(this.body, this.air, jumpDown, dt);
+      const wasGrounded = this.body.grounded;
       stepBody(this.body, this.chunks.map(c => c.world), dt);
+      landing(this.body, this.air, wasGrounded, dt);
       this.motion.vx = this.body.vx;
       remaining -= dt;
     }
     if (this.body.y > 900 || this.chunks.some(c => c.world.noGo.some(box => overlaps(this.body, box)))) {
       Object.assign(this.body, { x: this.spawn.x, y: this.spawn.y, vx: 0, vy: 0, grounded: true });
       this.motion = movement();
+      this.air = jumpState(this.body.y);
     }
+    const pose = this.air.landing > 0 ? this.air.hard
+      ? `hard-landing-${String(Math.min(3, Math.floor((4 / 12 - this.air.landing) * 12))).padStart(2, '0')}`
+      : 'jump-08' : !this.body.grounded ? this.body.vy < 0 ? 'jump-02' : 'fall-00' : null;
+    if (pose && this.scene.textures.get('hero-air').has(pose)) this.sprite.setTexture('hero-air', pose);
+    else this.sprite.setTexture('hero-move', 'idle-00');
     this.sprite.setPosition(Math.round(this.body.x), Math.round(this.body.y)).setFlipX(this.motion.facing < 0);
     if (axis) this.lastSpeed = Math.abs(this.body.vx);
     this.debug.clear();
     if (this.showDebug) this.debug.lineStyle(2, 0xffffff).strokeRect(this.body.x - BODY_WIDTH / 2,
       this.body.y - BODY_HEIGHT, BODY_WIDTH, BODY_HEIGHT);
-    this.label.setText(`vx ${this.body.vx.toFixed(1)} px/s | last ${this.lastSpeed.toFixed(1)} (${(this.lastSpeed / 43).toFixed(2)} m/s)\nheld ${this.motion.held.toFixed(2)}s | x ${this.body.x.toFixed(1)} y ${this.body.y.toFixed(1)}`);
+    this.label.setText(`vx ${this.body.vx.toFixed(1)} px/s | last ${this.lastSpeed.toFixed(1)} (${(this.lastSpeed / 43).toFixed(2)} m/s)\nheld ${this.motion.held.toFixed(2)}s | x ${this.body.x.toFixed(1)} y ${this.body.y.toFixed(1)}\njump ${this.air.height.toFixed(1)}px | landing ${this.air.hard ? 'hard' : 'normal'}`);
   }
 }