unity-csharp-scripting

Unity C# Scripting (MonoBehaviour)

Write correct, idiomatic gameplay scripts in Unity 6. Get the lifecycle, component access, serialization, and coroutines right so behaviour is deterministic and the Inspector stays useful. Targets Unity 6.3 LTS (6000.3), C# / .NET Standard 2.1.

When to use

• Use when authoring or fixing a MonoBehaviour: choosing the right lifecycle callback, reading/caching components, exposing fields to the Inspector, or running timed logic with coroutines.
• Use when the project has *.cs files, an Assembly-CSharp or *.asmdef, and a ProjectSettings/ folder.

When not to use: moving rigidbodies / collision response → unity-physics; reading player input → unity-input-system; shared data assets / config → unity-scriptableobjects; Animator parameters → unity-animation. This skill owns the script lifecycle and C# plumbing, not those subsystems.

Core workflow

1. Pick the callback by purpose, not habit. Awake (cache references, runs once on load), OnEnable (subscribe to events), Start (init that depends on other objects' Awake), Update (per-frame logic/input polling), FixedUpdate (physics), LateUpdate (camera follow after movement), OnDisable/OnDestroy (unsubscribe/cleanup).
2. Cache component lookups in Awake — never call GetComponent every frame.
3. Expose tunables with [SerializeField] private, not public fields, so other code can't mutate them but designers can edit them in the Inspector.
4. Scale per-frame values by Time.deltaTime in Update (and Time.fixedDeltaTime semantics are automatic in FixedUpdate).
5. Use coroutines for time-sequenced logic (delays, tweens, "do X then wait then Y"); start them with StartCoroutine and stop them deterministically.
6. Verify in Play mode: check the Console for null-reference exceptions, confirm values in the Inspector update as expected, and watch the Profiler if Update is hot.

Patterns