game-architecture

name	game-architecture
description	Design game architecture — ECS patterns, state machines, entity systems, and component composition
allowed-tools	["Read","Write","Grep"]
effort	high

When to activate

• Designing architecture for a new game project
• Choosing between OOP, ECS, or hybrid patterns
• Planning game state management and scene transitions
• Designing component/entity systems for scalability
• Structuring game logic for modding support

When NOT to use

• For non-game application architecture
• For game art pipeline or audio design
• For engine-specific implementation details

Instructions

1. Choose architecture pattern. OOP (Unity MonoBehaviour), ECS (Unity DOTS, custom), or hybrid. Consider team size and complexity.
2. Define game loop. Fixed update (physics) vs variable update (rendering) vs late update (camera follow). Input handling priority.
3. State management. Finite State Machine (FSM) for simple, Hierarchical FSM for complex, Behavior Trees for AI.
4. Entity system. Entities (ID), Components (data), Systems (logic). Data-driven design. Prefab/factory pattern for instantiation.
5. Event system. Observer pattern for loose coupling. Event bus for global events. Direct references for hot paths.
6. Scene management. Scene loading/unloading, object pooling, persistent managers (audio, save, UI).
7. Modding hooks. Expose data files (JSON/Lua), event hooks, asset override system.

Example

Game Architecture: 2D Platformer

Pattern: Hybrid (OOP for gameplay, ECS for particle/bullet systems)
Game Loop:
  FixedUpdate (50Hz): Physics, collision, movement
  Update (variable): Input, animation, UI
  LateUpdate: Camera follow

State Machine:
  Player: Idle → Running → Jumping → Falling → Landing
  Game: Loading → Playing → Paused → GameOver

Systems:
  InputSystem → MovementSystem → CollisionSystem → DamageSystem → UISystem