game-developer

SKILL.md

Game Developer

Core Workflow

Analyze requirements — Identify genre, platforms, performance targets, multiplayer needs

Design architecture — Plan ECS/component systems, optimize for target platforms

Implement — Build core mechanics, graphics, physics, AI, networking

Optimize — Profile and optimize for 60+ FPS, minimize memory/battery usage

✅ Validation checkpoint: Run Unity Profiler or Unreal Insights; verify frame time ≤16 ms (60 FPS) before proceeding. Identify and resolve CPU/GPU bottlenecks iteratively.

Test — Cross-platform testing, performance validation, multiplayer stress tests

✅ Validation checkpoint: Confirm stable frame rate under stress load; run multiplayer latency/desync tests before shipping.

Reference Guide

Load detailed guidance based on context:

Topic
Reference
Load When

Unity Development
references/unity-patterns.md
Unity C#, MonoBehaviour, Scriptable Objects

Unreal Development
references/unreal-cpp.md
Unreal C++, Blueprints, Actor components

ECS & Patterns
references/ecs-patterns.md
Entity Component System, game patterns

Performance
references/performance-optimization.md
FPS optimization, profiling, memory

Networking
references/multiplayer-networking.md
Multiplayer, client-server, lag compensation

Constraints

MUST DO

Target 60+ FPS on all platforms

Use object pooling for frequent instantiation

Implement LOD systems for optimization

Profile performance regularly (CPU, GPU, memory)

Use async loading for resources

Implement proper state machines for game logic

Cache component references (avoid GetComponent in Update)

Use delta time for frame-independent movement

MUST NOT DO

Instantiate/Destroy in tight loops or Update()

Skip profiling and performance testing

Use string comparisons for tags (use CompareTag)

Allocate memory in Update/FixedUpdate loops

Ignore platform-specific constraints (mobile, console)

Use Find methods in Update loops

Hardcode game values (use ScriptableObjects/data files)

Output Templates

When implementing game features, provide:

Core system implementation (ECS component, MonoBehaviour, or Actor)

Associated data structures (ScriptableObjects, structs, configs)

Performance considerations and optimizations

Brief explanation of architecture decisions

Key Code Patterns

Object Pooling (Unity C#)

public class ObjectPool<T> where T : Component
{
    private readonly Queue<T> _pool = new();
    private readonly T _prefab;
    private readonly Transform _parent;

    public ObjectPool(T prefab, int initialSize, Transform parent = null)
    {
        _prefab = prefab;
        _parent = parent;
        for (int i = 0; i < initialSize; i++)
            Release(Create());
    }

    public T Get()
    {
        T obj = _pool.Count > 0 ? _pool.Dequeue() : Create();
        obj.gameObject.SetActive(true);
        return obj;
    }

    public void Release(T obj)
    {
        obj.gameObject.SetActive(false);
        _pool.Enqueue(obj);
    }

    private T Create() => Object.Instantiate(_prefab, _parent);
}

Component Caching (Unity C#)

public class PlayerController : MonoBehaviour
{
    // Cache all component references in Awake — never call GetComponent in Update
    private Rigidbody _rb;
    private Animator _animator;
    private PlayerInput _input;

    private void Awake()
    {
        _rb = GetComponent<Rigidbody>();
        _animator = GetComponent<Animator>();
        _input = GetComponent<PlayerInput>();
    }

    private void FixedUpdate()
    {
        // Use cached references; use deltaTime for frame-independence
        Vector3 move = _input.MoveDirection * (speed * Time.fixedDeltaTime);
        _rb.MovePosition(_rb.position + move);
    }
}

State Machine (Unity C#)

public abstract class State
{
    public abstract void Enter();
    public abstract void Tick(float deltaTime);
    public abstract void Exit();
}

public class StateMachine
{
    private State _current;

    public void TransitionTo(State next)
    {
        _current?.Exit();
        _current = next;
        _current.Enter();
    }

    public void Tick(float deltaTime) => _current?.Tick(deltaTime);
}

// Usage example
public class IdleState : State
{
    private readonly Animator _animator;
    public IdleState(Animator animator) => _animator = animator;
    public override void Enter() => _animator.SetTrigger("Idle");
    public override void Tick(float deltaTime) { /* poll transitions */ }
    public override void Exit() { }
}

Documentation
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