game-development

You are working on a game development project. This skill teaches the PRINCIPLES of game development and directs you to the right sub-skill based on context.

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Platform Selection

| If the game targets... | Use Sub-Skill |

|------------------------|---------------|

| Web browsers (HTML5, WebGL) | game-development/web-games |

| Mobile (iOS, Android) | game-development/mobile-games |

| PC (Steam, Desktop) | game-development/pc-games |

| VR/AR headsets | game-development/vr-ar |

Dimension Selection

| If the game is... | Use Sub-Skill |

|-------------------|---------------|

| 2D (sprites, tilemaps) | game-development/2d-games |

| 3D (meshes, shaders) | game-development/3d-games |

Specialty Areas

| If you need... | Use Sub-Skill |

|----------------|---------------|

| GDD, balancing, player psychology | game-development/game-design |

| Multiplayer, networking | game-development/multiplayer |

| Visual style, asset pipeline, animation | game-development/game-art |

| Sound design, music, adaptive audio | game-development/game-audio |

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1. The Game Loop

Every game, regardless of platform, follows this pattern:

```

INPUT → Read player actions

UPDATE → Process game logic (fixed timestep)

RENDER → Draw the frame (interpolated)

```

Fixed Timestep Rule:

• Physics/logic: Fixed rate (e.g., 50Hz)
• Rendering: As fast as possible
• Interpolate between states for smooth visuals

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2. Pattern Selection Matrix

| Pattern | Use When | Example |

|---------|----------|---------|

| State Machine | 3-5 discrete states | Player: Idle→Walk→Jump |

| Object Pooling | Frequent spawn/destroy | Bullets, particles |

| Observer/Events | Cross-system communication | Health→UI updates |

| ECS | Thousands of similar entities | RTS units, particles |

| Command | Undo, replay, networking | Input recording |

| Behavior Tree | Complex AI decisions | Enemy AI |

Decision Rule: Start with State Machine. Add ECS only when performance demands.

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3. Input Abstraction

Abstract input into ACTIONS, not raw keys:

```

"jump" → Space, Gamepad A, Touch tap

"move" → WASD, Left stick, Virtual joystick

```

Why: Enables multi-platform, rebindable controls.

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4. Performance Budget (60 FPS = 16.67ms)

| System | Budget |

|--------|--------|

| Input | 1ms |

| Physics | 3ms |

| AI | 2ms |

| Game Logic | 4ms |

| Rendering | 5ms |

| Buffer | 1.67ms |

Optimization Priority:

1. Algorithm (O(n²) → O(n log n))
2. Batching (reduce draw calls)
3. Pooling (avoid GC spikes)
4. LOD (detail by distance)
5. Culling (skip invisible)

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5. AI Selection by Complexity

| AI Type | Complexity | Use When |

|---------|------------|----------|

| FSM | Simple | 3-5 states, predictable behavior |

| Behavior Tree | Medium | Modular, designer-friendly |

| GOAP | High | Emergent, planning-based |

| Utility AI | High | Scoring-based decisions |

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6. Collision Strategy

| Type | Best For |

|------|----------|

| AABB | Rectangles, fast checks |

| Circle | Round objects, cheap |

| Spatial Hash | Many similar-sized objects |

| Quadtree | Large worlds, varying sizes |

---

| Don't | Do |

|-------|-----|

| Update everything every frame | Use events, dirty flags |

| Create objects in hot loops | Object pooling |

| Cache nothing | Cache references |

| Optimize without profiling | Profile first |

| Mix input with logic | Abstract input layer |

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Example 1: "I want to make a browser-based 2D platformer"

→ Start with game-development/web-games for framework selection

→ Then game-development/2d-games for sprite/tilemap patterns

→ Reference game-development/game-design for level design

Example 2: "Mobile puzzle game for iOS and Android"

→ Start with game-development/mobile-games for touch input and stores

→ Use game-development/game-design for puzzle balancing

Example 3: "Multiplayer VR shooter"

→ game-development/vr-ar for comfort and immersion

→ game-development/3d-games for rendering

→ game-development/multiplayer for networking

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> Remember: Great games come from iteration, not perfection. Prototype fast, then polish.