Pawn and Character

Possess-able actor classes. A Controller (APlayerController or AAIController) possesses a Pawn to drive it.

APawn

Minimal possess-able actor. Has no built-in movement, mesh, or input — bring your own.

| When to use | Vehicles, spaceships, custom physics-driven actors |

ACharacter

ACharacter extends APawn with:

• CapsuleComponent (root, collision)
• CharacterMovementComponent (CMC) — full kinematic locomotion with Walking / Falling / Swimming / Flying / Custom modes
• SkeletalMeshComponent (visual)
• Network-replicated movement with prediction + server reconciliation

| When to use | Bipeds, animals, anything that walks/runs/jumps |

CharacterMovementComponent

Properties worth knowing:

Property	Effect
MaxWalkSpeed / MaxAcceleration	Ground locomotion
JumpZVelocity	Jump impulse
GravityScale	1.0 default; physics volume can override
AirControl	0–1 lateral control while falling
bUseControllerDesiredRotation / bOrientRotationToMovement	Character faces input vs faces controller
CrouchedHalfHeight	Capsule size while crouched
MaxStepHeight	Auto-step-up threshold
WalkableFloorAngle	Steep slope cutoff
NavAgentProps	Used by AI nav system

Input wiring (Enhanced Input)

void AMyChar::SetupPlayerInputComponent(UInputComponent* Input)
{
    UEnhancedInputComponent* EI = Cast<UEnhancedInputComponent>(Input);
    EI->BindAction(MoveAction, ETriggerEvent::Triggered, this, &AMyChar::HandleMove);
    EI->BindAction(JumpAction, ETriggerEvent::Started, this, &ACharacter::Jump);
}

Controllers

Controller	Use
APlayerController	Local + remote players; per-player UI, input, camera
AAIController	NPCs; usually wraps a UBlackboardComponent + UBehaviorTreeComponent

Possession: PlayerController->Possess(MyPawn).

Network movement

Character movement is client-predicted with server reconciliation out of the box. The client simulates locally and sends moves to the server; the server validates and corrects.

• Set Replicates = true on the Character
• Set Replicate Movement = true
• Custom velocity changes that aren't via the CMC must be replicated manually

Common subclasses

• Player Characters — extend ACharacter, add cameras, abilities, inventory
• AI Characters — extend ACharacter + AAIController + BehaviorTree
• Vehicles — extend APawn + UChaosVehicleMovementComponent
• Spectators — use ASpectatorPawn

Gotchas

• Capsule radius must clear navmesh agent radius or AI can't path to the same spots as the player.
• Crouching changes the capsule height which can pop the camera — bind the camera to a SpringArmComponent to smooth it.
• Replicated movement requires the server's Character to have bReplicates = true AND bReplicateMovement = true.