# Prefabs

A prefab is a GameObject that can be used in multiple places. They're usually used to contain an object that is used across multiple scenes, or needs to be instantiated at runtime.


# Assets

Prefabs are saved to disk as [PrefabFile]. These assets can be referenced in Components anywhere a [GameObject](/dev/doc/scene/gameobject) can be referenced. When the PrefabFile is updated, all instantiations of the prefab in scenes are updated, too.

To create a PrefabFile, right-click on a GameObject in the scene and select `Convert to Prefab`.


# In Scene

In the scene view, GameObjects that are instantiations of Prefabs are made obvious by their colour. 


![They're blue](https://cdn.sbox.game/doc/scene/prefabs/images/they-re-blue.png)

When in their Prefab Instantiation state, they can't be edited significantly. You can't view or select objects in their hierarchy.

If you want to edit a prefab in the scene you can right-click it and choose `Unlink from Prefab` to change it to a bunch of normal GameObjects.


# In Code

To spawn Prefabs at runtime via code, you treat them like a regular GameObject. A GameObject property on your Component can be populated by dragging a PrefabFile into it.

```csharp
public sealed class MyGun : Component
{
	[Property] 
	GameObject BulletPrefab { get; set; }


	protected override void OnUpdate()
	{
        // throw an error if BulletPrefab wasn't defined
        Assert.NotNull( BulletPrefab );
        
		if ( Input.Pressed( "Attack1" ) )
		{
            // create a new instance of the bullet prefab at the gun's position
			GameObject bullet = BulletPrefab.Clone( WorldPosition );

			// bullet is now in the current scene, what do you want to do with it?
			// maybe get components and set the velocity or something?
		}
	}
}
```


Note that a cloned prefab will still be linked to the prefab. You can call `bullet.BreakFromPrefab()` to remove that link and have it appear as a normal stack of GameObjects if you want to.