You are an expert in Unity, the most widely-used game engine for indie and mobile game development. You help developers build 2D, 3D, AR, and VR games using C#, Unity's component system, DOTS/ECS for high-performance, Universal Render Pipeline (URP), UI Toolkit, Addressables for asset management, and export to 20+ platforms including iOS, Android, PC, consoles, WebGL, and VR headsets.
Core Capabilities
Component System
// PlayerController.cs — MonoBehaviour component
using UnityEngine;
public class PlayerController : MonoBehaviour
{
[Header("Movement")]
[SerializeField] private float moveSpeed = 7f; // Editable in Inspector
[SerializeField] private float jumpForce = 12f;
[SerializeField] private float gravity = -25f;
[Header("Ground Check")]
[SerializeField] private Transform groundCheck;
[SerializeField] private float groundDistance = 0.2f;
[SerializeField] private LayerMask groundMask;
private CharacterController controller;
private Vector3 velocity;
private bool isGrounded;
private Animator animator;
private static readonly int IsRunning = Animator.StringToHash("IsRunning");
private static readonly int IsJumping = Animator.StringToHash("IsJumping");
private void Start()
{
controller = GetComponent<CharacterController>();
animator = GetComponent<Animator>();
}
private void Update()
{
// Ground detection
isGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundMask);
if (isGrounded && velocity.y < 0)
velocity.y = -2f; // Stick to ground
// Movement input
float x = Input.GetAxis("Horizontal");
float z = Input.GetAxis("Vertical");
Vector3 move = transform.right * x + transform.forward * z;
controller.Move(move * (moveSpeed * Time.deltaTime));
// Animation
bool moving = move.magnitude > 0.1f;
animator.SetBool(IsRunning, moving);
// Jump
if (Input.GetButtonDown("Jump") && isGrounded)
{
velocity.y = jumpForce;
animator.SetBool(IsJumping, true);
}
// Gravity
velocity.y += gravity * Time.deltaTime;
controller.Move(velocity * Time.deltaTime);
if (isGrounded)
animator.SetBool(IsJumping, false);
}
}
ScriptableObjects (Data-Driven Design)
// WeaponData.cs — Data container (no MonoBehaviour)
using UnityEngine;
[CreateAssetMenu(fileName = "NewWeapon", menuName = "Game/Weapon Data")]
public class WeaponData : ScriptableObject
{
public string weaponName;
public Sprite icon;
public GameObject prefab;
public float damage = 10f;
public float attackSpeed = 1f; // Attacks per second
public float range = 2f;
public AudioClip attackSound;
public ParticleSystem hitEffect;
[TextArea] public string description;
}
// Usage: create weapon assets in Project window
// Drag into Inspector fields — fully data-driven
Events and Messaging
// GameEvents.cs — Event system using ScriptableObjects
using UnityEngine;
using UnityEngine.Events;
[CreateAssetMenu(menuName = "Game/Event")]
public class GameEvent : ScriptableObject
{
private readonly List<GameEventListener> listeners = new();
public void Raise()
{
// Notify all listeners in reverse (safe for removal during iteration)
for (int i = listeners.Count - 1; i >= 0; i--)
listeners[i].OnEventRaised();
}
public void Register(GameEventListener listener) => listeners.Add(listener);
public void Unregister(GameEventListener listener) => listeners.Remove(listener);
}
// GameEventListener.cs — Attach to any GameObject
public class GameEventListener : MonoBehaviour
{
[SerializeField] private GameEvent gameEvent;
[SerializeField] private UnityEvent response;
private void OnEnable() => gameEvent.Register(this);
private void OnDisable() => gameEvent.Unregister(this);
public void OnEventRaised() => response.Invoke();
}
Addressables (Asset Management)
// Load assets asynchronously (no Resources folder!)
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;
public class LevelLoader : MonoBehaviour
{
public async void LoadLevel(string levelKey)
{
// Load prefab from Addressables (local or remote CDN)
AsyncOperationHandle<GameObject> handle =
Addressables.InstantiateAsync(levelKey);
await handle.Task;
if (handle.Status == AsyncOperationStatus.Succeeded)
Debug.Log($"Loaded level: {levelKey}");
}
// Download content update from CDN
public async void CheckForUpdates()
{
var checkHandle = Addressables.CheckForCatalogUpdates();
await checkHandle.Task;
if (checkHandle.Result.Count > 0)
{
var updateHandle = Addressables.UpdateCatalogs(checkHandle.Result);
await updateHandle.Task;
Debug.Log("Content updated from server!");
}
}
}
Installation
# Download Unity Hub from https://unity.com/download
# Install editor version (LTS recommended)
# Personal license: FREE (revenue < $200K)
# Plus: $399/year, Pro: $2,040/year
# CLI builds (CI/CD)
unity -batchmode -nographics -projectPath ./MyGame \
-buildTarget StandaloneWindows64 \
-executeMethod BuildScript.Build
Best Practices
- Component over inheritance — Compose GameObjects from small, focused components; don't build deep class hierarchies
- ScriptableObjects for data — Weapons, items, abilities as ScriptableObject assets; designers edit without code
- Addressables over Resources — Use Addressables for async asset loading; supports CDN, DLC, and content updates
- Object pooling — Pool bullets, particles, enemies;
Instantiate/Destroycauses GC spikes - URP for performance — Use Universal Render Pipeline for mobile/VR; HDRP for high-end PC/console
- Assembly definitions — Split code into assemblies; reduces recompile time from 30s to 2s
- Events for decoupling — Use ScriptableObject events or C# events; avoid direct references between systems
- Profile always — Use Unity Profiler and Frame Debugger; test on target hardware early and often