# GKComponent The abstract superclass for creating objects that add specific gameplay functionality to an entity. ``` class GKComponent ``` ## Overview [`GKComponent`](/documentation/GameplayKit/GKComponent) is the abstract superclass for custom component classes you create when building a game with Entity-Component architecture. In this architecture, an *entity* is an object relevant to the game, and a *component* is an object that handles specific aspects of an entity’s behavior in a general way. Because a component’s scope of functionality is limited, you can reuse the same component class for many different kinds of entities. You create components by subclassing [`GKComponent`](/documentation/GameplayKit/GKComponent) to implement reusable behavior. Then, you build game entities by creating [`GKEntity`](/documentation/GameplayKit/GKEntity) objects and using the [`addComponent(_:)`](/documentation/GameplayKit/GKEntity/addComponent(_:)) method to attach instances of your custom component classes. At runtime, a component-based game needs to dispatch periodic logic—from an update/render loop method such as (SpriteKit) or (SceneKit), or a (iOS) or (macOS) timer in a custom rendering engine—to each of its components. GameplayKit provides two mechanisms for dispatching updates: - Per-entity. Call each entity’s [`update(deltaTime:)`](/documentation/GameplayKit/GKEntity/update(deltaTime:)) method, which will then forward to the [`update(deltaTime:)`](/documentation/GameplayKit/GKComponent/update(deltaTime:)) method of each component. This option can be quickly implemented in games with a small number of entities and components. - Per-component. Use a [`GKComponentSystem`](/documentation/GameplayKit/GKComponentSystem) object to handle all instances of a specific component class. When you call a component system’s [`update(deltaTime:)`](/documentation/GameplayKit/GKComponentSystem/update(deltaTime:)) method, it forwards to the [`update(deltaTime:)`](/documentation/GameplayKit/GKComponent/update(deltaTime:)) method of all the component objects it manages. Because a component system needs no knowledge of your game’s entity/component hierarchy, this option works well for games with complex object graphs. For more information on Entity-Component architecture, read [Entities and Components](https://developer.apple.com/library/archive/documentation/General/Conceptual/GameplayKit_Guide/EntityComponent.html#//apple_ref/doc/uid/TP40015172-CH6) in [GameplayKit Programming Guide](https://developer.apple.com/library/archive/documentation/General/Conceptual/GameplayKit_Guide/index.html#//apple_ref/doc/uid/TP40015172). ## Topics ### Performing Periodic Updates [`- updateWithDeltaTime:`](/documentation/GameplayKit/GKComponent/update(deltaTime:)) Performs any custom periodic actions defined by the component subclass. ### Working with Entities [`entity`](/documentation/GameplayKit/GKComponent/entity) The entity that owns this component. [`- didAddToEntity`](/documentation/GameplayKit/GKComponent/didAddToEntity()) Notifies the component that it has been assigned to an entity. [`- willRemoveFromEntity`](/documentation/GameplayKit/GKComponent/willRemoveFromEntity()) Notifies the component that it has been removed from an entity. ## Relationships ### Conforms To [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) [`NSCoding`](/documentation/Foundation/NSCoding) [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`Hashable`](/documentation/Swift/Hashable) [`CVarArg`](/documentation/Swift/CVarArg) [`NSSecureCoding`](/documentation/Foundation/NSSecureCoding) [`Equatable`](/documentation/Swift/Equatable) [`NSCopying`](/documentation/Foundation/NSCopying) ### Inherited By [`GKSKNodeComponent`](/documentation/GameplayKit/GKSKNodeComponent) [`GKAgent`](/documentation/GameplayKit/GKAgent) [`GKSCNNodeComponent`](/documentation/GameplayKit/GKSCNNodeComponent) ### Inherits From [`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)