--- name: Actor last_updated: 2026-06-11T17:05:15Z inherits: - Model - PVInstance - Instance - Object type: class memory_category: BaseParts summary: "An Actor is a container for code that can be safely split into its own thread." --- # Class: Actor > An [Actor](/docs/reference/engine/classes/Actor.md) is a container for code that can be safely split into its own > thread. ## Description An [Actor](/docs/reference/engine/classes/Actor.md) is a container for code that can be safely split into its own thread using [task.desynchronize()](/docs/reference/engine/globals/task.md). It should also contain the instances used by its scripts. To learn more about using multiple Actors to optimize script performance, see [Parallel Luau](/docs/en-us/scripting/multithreading.md). #### Notes - Each `Actor` runs in its own Luau VM. [ModuleScripts](/docs/reference/engine/classes/ModuleScript.md) required by an `Actor` are **not** shared or cached across `Actors` or with the main thread. Each VM executes its own copy of the module, so module-level state is isolated per `Actor`. Design accordingly if your modules hold state you intend to share. - `script:GetActor()` returns `nil` when called from a [ModuleScript](/docs/reference/engine/classes/ModuleScript.md) unless the `ModuleScript` is a descendant of the `Actor`. `ModuleScripts` stored elsewhere (for example, [ReplicatedStorage](/docs/reference/engine/classes/ReplicatedStorage.md)) and required by an `Actor` are not considered descendants of the `Actor`. ## Methods ### Method: Actor:BindToMessage **Signature:** `Actor:BindToMessage(topic: string, function: Function): RBXScriptConnection` This method is used to bind a Luau callback to a message with the specified topic. When a message is sent (using [SendMessage()](/docs/reference/engine/classes/Actor.md)) to the topic specified the provided callback will be called in a _serial_ execution context. Multiple Luau callbacks may be bound to a single actor and even to a single message topic. Note: Only the scripts which are descendants of an Actor may bind to its messages. ```lua local actor = script:GetActor() -- Print out a message when a greeting message is sent to the Actor -- this script is a descendant of. local connection = actor:BindToMessage("Greeting", function(message) print("Received Greeting Message:", message) end) ``` *Security: None · Thread Safety: Safe · Capabilities: Basic* **Parameters:** | Name | Type | Default | Description | |------|------|---------|-------------| | `topic` | `string` | | The topic used to identify the type of message. | | `function` | `Function` | | | **Returns:** `RBXScriptConnection` — This connection object may be used to disconnect the Luau callback from receiving messages. ### Method: Actor:BindToMessageParallel **Signature:** `Actor:BindToMessageParallel(topic: string, function: Function): RBXScriptConnection` This method is used to bind a Luau callback to a message with the specified topic. When a message is sent (using [SendMessage()](/docs/reference/engine/classes/Actor.md)) to the topic specified the provided callback will be called in a _parallel_ execution context. Multiple Luau callbacks may be bound to a single actor and even to a single message topic. Note: Only the scripts which are descendants of an Actor may bind to its messages. ```lua local actor = script:GetActor() -- Print out a message when a greeting message is sent to the Actor -- this script is a descendant of. local connection = actor:BindToMessageParallel("Greeting", function(message) print("Received Greeting Message:", message) end) ``` *Security: None · Thread Safety: Safe · Capabilities: Basic* **Parameters:** | Name | Type | Default | Description | |------|------|---------|-------------| | `topic` | `string` | | The topic used to identify the type of message. | | `function` | `Function` | | | **Returns:** `RBXScriptConnection` — This connection object may be used to disconnect the Luau callback from receiving messages. ### Method: Actor:SendMessage **Signature:** `Actor:SendMessage(topic: string, message: Tuple): ()` Sends a message to an Actor. Messages are sent asynchronously, so the sender will not block or yield when calling the [SendMessage()](/docs/reference/engine/classes/Actor.md) method. Since a single Actor may receive different kinds of messages, a `topic` parameter is used to distinguish between various kinds of messages. See [BindToMessage()](/docs/reference/engine/classes/Actor.md) for details on receiving a message sent using [SendMessage()](/docs/reference/engine/classes/Actor.md). Note that message arguments are **passed by copy** across Luau VM boundaries, not by reference. Sending large tables incurs a full copy on each call. Functions are bound to a specific VM and cannot be passed in messages. ```lua -- Assume `actor` is a local variable referring to an Actor instance actor:SendMessage("Greeting", "Hello World") ``` *Security: None · Thread Safety: Safe · Capabilities: Basic* **Parameters:** | Name | Type | Default | Description | |------|------|---------|-------------| | `topic` | `string` | | The topic used to identify the message being sent. | | `message` | `Tuple` | | The contents of the message to send to the Actor. | **Returns:** `()` ## Inherited Members ### From [Model](/docs/reference/engine/classes/Model.md) - **Property `LevelOfDetail`** (`ModelLevelOfDetail`): Sets the level of detail on the model for experiences with instance - **Property `ModelStreamingMode`** (`ModelStreamingMode`): Controls the model streaming behavior on Models when - **Property `PrimaryPart`** (`BasePart`): The primary part of the Model, or `nil` if not explicitly set. - **Property `Scale`** (`float`): Editor-only property used to scale the model around its pivot. Setting - **Property `WorldPivot`** (`CFrame`): Determines where the pivot of a Model which does **not** have a - **Method `AddPersistentPlayer(playerInstance?: Player): ()`**: Sets this model to be persistent for the specified player. - **Method `BreakJoints(): ()`**: Breaks connections between `BaseParts`, including surface connections with *(deprecated)* - **Method `breakJoints(): ()`**: *(deprecated)* - **Method `GetBoundingBox(): Tuple`**: Returns a description of a volume that contains all parts of a Model. - **Method `GetExtentsSize(): Vector3`**: Returns the size of the smallest bounding box that contains all of the - **Method `GetModelCFrame(): CFrame`**: This value historically returned the CFrame of a central position in the *(deprecated)* - **Method `GetModelSize(): Vector3`**: Returns the Vector3 size of the Model. *(deprecated)* - **Method `GetPersistentPlayers(): List`**: Returns all the Player objects that this model object is - **Method `GetPrimaryPartCFrame(): CFrame`**: Returns the CFrame of the model's Model.PrimaryPart. *(deprecated)* - **Method `GetScale(): float`**: Returns the canonical scale of the model, which defaults to 1 for newly - **Method `MakeJoints(): ()`**: Goes through all BaseParts in the Model. If any *(deprecated)* - **Method `makeJoints(): ()`**: *(deprecated)* - **Method `move(location: Vector3): ()`**: *(deprecated)* - **Method `MoveTo(position: Vector3): ()`**: Moves the PrimaryPart to the given position. If - **Method `moveTo(location: Vector3): ()`**: *(deprecated)* - **Method `RemovePersistentPlayer(playerInstance?: Player): ()`**: Makes this model no longer persistent for the specified player. - **Method `ResetOrientationToIdentity(): ()`**: Resets the rotation of the model's parts to the previously set identity *(deprecated)* - **Method `ScaleTo(newScaleFactor: float): ()`**: Sets the scale factor of the model, adjusting the sizing and location of - **Method `SetIdentityOrientation(): ()`**: Sets the identity rotation of the given model, allowing you to reset the *(deprecated)* - **Method `SetPrimaryPartCFrame(cframe: CFrame): ()`**: Sets the BasePart.CFrame of the model's Model.PrimaryPart. *(deprecated)* - **Method `TranslateBy(delta: Vector3): ()`**: Shifts a Model by the given Vector3 offset, preserving ### From [PVInstance](/docs/reference/engine/classes/PVInstance.md) - **Property `Origin`** (`CFrame`): - **Property `Pivot Offset`** (`CFrame`): - **Method `GetPivot(): CFrame`**: Gets the pivot of a PVInstance. - **Method `PivotTo(targetCFrame: CFrame): ()`**: Transforms the PVInstance along with all of its descendant ### From [Instance](/docs/reference/engine/classes/Instance.md) - **Property `Archivable`** (`boolean`): Determines if an Instance and its descendants can be cloned using - **Property `archivable`** (`boolean`): *(deprecated, hidden)* - **Property `Capabilities`** (`SecurityCapabilities`): The set of capabilities allowed to be used for scripts inside this - **Property `Name`** (`string`): A non-unique identifier of the Instance. - **Property `Parent`** (`Instance`): Determines the hierarchical parent of the Instance. - **Property `PredictionMode`** (`PredictionMode`): - **Property `RobloxLocked`** (`boolean`): A deprecated property that used to protect CoreGui objects. *(hidden)* - **Property `Sandboxed`** (`boolean`): When enabled, the instance can only access abilities in its `Capabilities` - **Property `UniqueId`** (`UniqueId`): A unique identifier for the instance. - **Method `AddTag(tag: string): ()`**: Applies a tag to the instance. - **Method `children(): Instances`**: Returns an array of the object's children. *(deprecated)* - **Method `ClearAllChildren(): ()`**: This method destroys all of an instance's children. - **Method `Clone(): Instance`**: Create a copy of an instance and all its descendants, ignoring instances - **Method `clone(): Instance`**: *(deprecated)* - **Method `Destroy(): ()`**: Sets the Instance.Parent property to `nil`, locks the - **Method `destroy(): ()`**: *(deprecated)* - **Method `FindFirstAncestor(name: string): Instance?`**: Returns the first ancestor of the Instance whose - **Method `FindFirstAncestorOfClass(className: string): Instance?`**: Returns the first ancestor of the Instance whose - **Method `FindFirstAncestorWhichIsA(className: string): Instance?`**: Returns the first ancestor of the Instance for whom - **Method `FindFirstChild(name: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance found with the given name. - **Method `findFirstChild(name: string, recursive?: boolean): Instance`**: *(deprecated)* - **Method `FindFirstChildOfClass(className: string): Instance?`**: Returns the first child of the Instance whose - **Method `FindFirstChildWhichIsA(className: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance for whom - **Method `FindFirstDescendant(name: string): Instance?`**: Returns the first descendant found with the given Instance.Name. - **Method `GetActor(): Actor?`**: Returns the Actor associated with the Instance, if any. - **Method `GetAttribute(attribute: string): Variant`**: Returns the value which has been assigned to the given attribute name. - **Method `GetAttributeChangedSignal(attribute: string): RBXScriptSignal`**: Returns an event that fires when the given attribute changes. - **Method `GetAttributes(): Dictionary`**: Returns a dictionary of the instance's attributes. - **Method `GetChildren(): Instances`**: Returns an array containing all of the instance's children. - **Method `getChildren(): Instances`**: *(deprecated)* - **Method `GetDebugId(scopeLength?: int): string`**: Returns a coded string of the debug ID used internally by Roblox. - **Method `GetDescendants(): Instances`**: Returns an array containing all of the descendants of the instance. - **Method `GetFullName(): string`**: Returns a string describing the instance's ancestry. - **Method `GetStyled(name: string, selector: string?): Variant`**: Returns the styled or explicitly modified value of the specified property, - **Method `GetStyledPropertyChangedSignal(property: string): RBXScriptSignal`**: - **Method `GetTags(): Array`**: Gets an array of all tags applied to the instance. - **Method `HasTag(tag: string): boolean`**: Check whether the instance has a given tag. - **Method `IsAncestorOf(descendant: Instance): boolean`**: Returns true if an Instance is an ancestor of the given - **Method `IsDescendantOf(ancestor: Instance): boolean`**: Returns `true` if an Instance is a descendant of the given - **Method `isDescendantOf(ancestor: Instance): boolean`**: *(deprecated)* - **Method `IsPropertyModified(property: string): boolean`**: Returns `true` if the value stored in the specified property is not equal - **Method `QueryDescendants(selector: string): Instances`**: - **Method `Remove(): ()`**: Sets the object's `Parent` to `nil`, and does the same for all its *(deprecated)* - **Method `remove(): ()`**: *(deprecated)* - **Method `RemoveTag(tag: string): ()`**: Removes a tag from the instance. - **Method `ResetPropertyToDefault(property: string): ()`**: Resets a property to its default value. - **Method `SetAttribute(attribute: string, value: Variant): ()`**: Sets the attribute with the given name to the given value. - **Method `WaitForChild(childName: string, timeOut: double): Instance`**: Returns the child of the Instance with the given name. If the - **Event `AncestryChanged`**: Fires when the Instance.Parent property of this object or one of - **Event `AttributeChanged`**: Fires whenever an attribute is changed on the Instance. - **Event `ChildAdded`**: Fires after an object is parented to this Instance. - **Event `childAdded`**: *(deprecated)* - **Event `ChildRemoved`**: Fires after a child is removed from this Instance. - **Event `DescendantAdded`**: Fires after a descendant is added to the Instance. - **Event `DescendantRemoving`**: Fires immediately before a descendant of the Instance is removed. - **Event `Destroying`**: Fires immediately before (or is deferred until after) the instance is - **Event `StyledPropertiesChanged`**: Fires whenever any style property is changed on the instance, including ### From [Object](/docs/reference/engine/classes/Object.md) - **Property `ClassName`** (`string`): A read-only string representing the class this Object belongs to. - **Property `className`** (`string`): *(deprecated)* - **Method `GetPropertyChangedSignal(property: string): RBXScriptSignal`**: Get an event that fires when a given property of the object changes. - **Method `IsA(className: string): boolean`**: Returns true if an object's class matches or inherits from a given class. - **Method `isA(className: string): boolean`**: *(deprecated)* - **Event `Changed`**: Fires immediately after a property of the object changes, with some