SpawnActorFromClass — spawn a new Actor into the world

Cast ReturnValue to the specific class to access its properties.

LaunchCharacter — launch character with velocity

ACharacter::LaunchCharacter. Good for knockback, bouncing, jumppads.

BeginPlay

Fires once on actor spawn (after construction). Use for setup that needs other actors in the world to exist.

Event BeginPlay — fires once when actor is spawned or game starts

RestartPlayer — respawn a player at a PlayerStart

Call on GameMode. The controller's StartSpot or nearest PlayerStart is used.

NewObject — create a new UObject instance (non-Actor)

For non-Actor objects (UObjects). Actors must use SpawnActorFromClass instead. Outer is usually 'self' or GetTransientPackage().

Spawn Actor

Creates a new Actor instance at runtime. Pass a Class Reference + Transform + Owner. Use BeginSpawnActor for deferred init.

CreateWidget — create a UserWidget instance

Always pass a valid PlayerController as OwningPlayer. Cast the ReturnValue to your specific widget class.

Game subsystem: persistent game manager with auto-init

SETUP: Create Blueprint inheriting UGameInstanceSubsystem (or UWorldSubsystem for level-scoped). Override Initialize(Collection) to set up. Override Deinitialize to clean up. Add game variables here (Score, PlayTime, Settings). ACCESS FROM ANYWHERE: GetGameInstance → GetSubsystem(BP_GameSubsystem) → CastTo<BP_GameSubsystem> → access variables. WHY: Subsystems auto-create, auto-destroy, and don't need FindActor. Better than GameInstance for well-organized systems. UGameInstanceSubsystem persists across levels. UWorldSubsystem is recreated each level.

Enhanced Input system setup with Input Actions and Mapping Context

Setup: Create InputAction assets (IA_Move Axis2D, IA_Jump Digital). Create InputMappingContext (IMC_Default) mapping keys to IAs. BeginPlay: GetPlayerController → GetEnhancedInputLocalPlayerSubsystem → AddMappingContext(IMC_Default, 0). Bind: EnhancedInputAction IA_Move → Triggered pin → ActionValue → BreakVector2D → AddMovementInput.