Actors & components

An Actor (AActor) is anything you can place or spawn in a level. Components are the reusable pieces of behavior/representation you compose onto actors. "Composition over inheritance" is the intended design: prefer adding components over deep actor class hierarchies.

When to use this skill

• Creating a new AActor or UActorComponent subclass.
• Setting up a component hierarchy (root + attached scene components) and choosing the root.
• Spawning actors (immediate or deferred) or adding/registering components at runtime.
• Wiring overlap/hit events, or deciding what runs in the constructor vs BeginPlay.
• Debugging "BeginPlay didn't run", "component has no transform / doesn't render", attachment problems, or "my runtime component does nothing".

Component types

UActorComponent is the base for all components. The three tiers, in increasing capability: