SetTimerByEvent — set timer that fires a custom event delegate

K2_SetTimerDelegate. Safer than FunctionName version. Create delegate from custom event.

Delegate

A type-safe function pointer used by Event Dispatchers and bindings. Bind, broadcast, unbind.

Event Dispatcher binding has wrong parameter types

Why: You're binding a function to an Event Dispatcher (Delegate), but the function's parameters don't match the dispatcher's expected signature '{expected}'. You passed '{got}'. Fix: Either: (a) change your function's input parameter types to match the dispatcher (open the function → My Blueprint → Inputs section → match types one-by-one), or (b) bind a DIFFERENT function whose signature already matches. The Details panel of the Bind Event node shows the expected signature.

Blueprint function vs custom event vs macro: when to use each

BLUEPRINT FUNCTION: - Has its own execution context, can have inputs/outputs/return value. - Cannot have Delay, Timeline, or latent nodes inside. - Best for: pure logic, calculations, data transformation. - Can be overridden in child BPs (if not pure). CUSTOM EVENT: - Lives in event graph, can be called like a function. - CAN have Delay, Timeline, latent nodes. - Can be Replicated (Server/Client/Multicast). - No return value. Best for: triggered behavior, RPC calls. MACRO: - Inlined at call site — like a code template. - CAN have multiple exec inputs AND outputs. - CAN contain latent nodes. - Best for: reusable flow patterns (e.g. 'IsValidAndCast' check-and-cast pattern). PURE FUNCTION: checked 'Pure' — no exec pins, evaluated on demand. Best for getters.

Possess — make a Controller possess a Pawn

Event Dispatcher: create, bind, and call with custom data

SETUP: In your BP, create an Event Dispatcher (e.g. 'OnPlayerDied') in the My Blueprint panel. BIND (in another BP): Get reference to actor → Bind Event to OnPlayerDied → connect a Custom Event as the target. CALL (in owning BP): Call OnPlayerDied (appears as a pink node) → this broadcasts to all bound listeners. Key: Event Dispatchers are called with 'Call <DispatcherName>' (not 'Broadcast'). Binding is done via 'Bind Event to <DispatcherName>' which has an 'Event' exec-like pin.

string

string

RetriggerableDelay — delay that resets if triggered again

UKismetSystemLibrary::RetriggerableDelay. Latent.

Health and damage system with ApplyDamage and EventAnyDamage

Dealing damage: Event → ApplyDamage(TargetActor, BaseDamage, InstigatorController, DamageCauser, DamageTypeClass). Receiving: EventAnyDamage → Damage output → Subtract_FloatFloat(CurrentHealth, Damage) → FClamp(Result, 0, MaxHealth) → SET CurrentHealth → Branch(CurrentHealth <= 0) → True: DestroyActor. Initialize CurrentHealth=MaxHealth in BeginPlay.

Enhanced Input BindAction — bind an Input Action to a Blueprint function (UE5 new input)

UE5 Enhanced Input replaces legacy BindAxis/BindAction. In BP: use 'Enhanced Action Events' category nodes (IA_ nodes appear automatically). ETriggerEvent: Started (pressed), Triggered (held), Completed (released). Input Action outputs: 'Action Value' (InputActionValue struct) and typed output.