> For the complete documentation index, see [llms.txt](https://cardstock-studio.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cardstock-studio.gitbook.io/docs/design/prefabs.md).
# Prefabs
**Prefabs** are a powerful way to reuse content multiple areas while retaining a single source of truth, where a change on the "Prefab" will update all Templates, Decks, and Books which use it. Instances of the Prefab can be overridden, retaining shared content while overriding specific values as needed, such as changing a color, or toggling layers in the prefab on or off.
***
## Create a Prefab
Right click any Layer that you want to turn into a Prefab, and choose "Create Prefab". This should be done after you've set up the Layer and children how you'd like — though you can update it later.
***
## Use a Prefab
In a Template or Book, click the "Add Layer" button, and choose "Prefabs", then the Prefab you'd like to add.
In your Layer stack, the Prefab will have a "\[PREFAB]" label on the right indicating it is a Prefab. The main "Prefab" layer is a placeholder, while the content IN the Prefab is a child of that.
{% hint style="info" %}
You can link prefab component values to a Variable, or use with Conditionals. However, making a Layer into a Prefab will strip those from the Prefab object itself, since other Tempaltes and use cases will not have the same Variables and Conditionals set up.
{% endhint %}
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## Overriding Values
Any change to any Layer or paremeter in the Components is an "Override". These changes will persist even when the Prefab is updated.
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## Applying Overrides
You can apply overrides to the prefab itself — doing so will affect all uses of the Prefabs in any other Template or Book.
To do this, select the "\[PREFAB]" layer. If changes have been made, you'll see information about that with the option to "Revert" or "Apply Overrides".
Reverting will remove the changes you've implemented. Otherwise, you can Apply Overrides to set your changes to all instances of the Prefab.
***
## Editing Prefabs
Click the "Prefabs" button in the top menu, and select the prefab you'd like to edit.
The Prefab view is similar to a Template, but without the card background. Add new Layers & Components, or make any adjustments. Any changes will be represented in all instnaces of the Prefab which aren't overriding the values.
---
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