# Stronghold Expansion Modules

Expansion Modules are "buildings" that can be added to one of your [Strongholds](../core-nft-player-assets/strongholds) "expansion pads" to unlock additional functionality inside the Mech.Game ecosystem.&#x20;

1 expansion pad can facilitate/hold 1 expansion module.

Here you can see a level 3 stronghold with 3 expansion pads used up and 4 pads still open:

<figure><img src="https://2189901203-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FySNjOQdhO6R687cGq3KU%2Fuploads%2FJE9uG1tNPQhhnPImQhwK%2FStronghold-forge-yard-office.png?alt=media&#x26;token=d6b5a954-897f-4f32-a9b3-c65c7816874d" alt=""><figcaption></figcaption></figure>

Each Expansion Module is an NFT item that can be owned and used by a player in the game or sold or traded on the marketplace.

There are different types of expansion modules and each of them provide different functionality or access in the game.  As the game progresses more expansion modules with even more functionality will be released.

As a player you will have the ability to mix and match whatever modules give you the desired outcome inside mech.game.  The only restriction is the number of expansion pads your stronghold has available.

Here are the expansion modules currently available:

#### Forge Expansion Module

<figure><img src="https://2189901203-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FySNjOQdhO6R687cGq3KU%2Fuploads%2FLKFdn2PYTgLowEJpcbUY%2FForge.png?alt=media&#x26;token=0a16b97a-4c9b-4f5c-b1bc-e6125adfaad1" alt=""><figcaption><p>Forge Expansion Pad</p></figcaption></figure>

The Forge is everybody's favorite expansion module because when you have one installed on your stronghold, it unlocks the ability to "forge" (create) new mechs from a blueprint and other resources.

#### Leasing Office Expansion Module

<figure><img src="https://2189901203-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FySNjOQdhO6R687cGq3KU%2Fuploads%2FlrC7cowMd7tKoxlEXubi%2FRam_Rend.png?alt=media&#x26;token=46444cbe-e97e-4d90-ba5e-9c48cc9af255" alt=""><figcaption><p>Leasing Office Expansion Pad</p></figcaption></figure>

The leasing office provides additional functionality for those NFT owners/players who want to rent/lease out a significant number of Mechs to scholars in exchange for a profit share.

All mech.game NFT owners can rent out a few mechs straight without the need for the leasing office, however some players own LARGE numbers of mechs and if they want to rent them all out they need a Leasing office to unlock that functionality.

#### Construction Yard Expansion Module

<figure><img src="https://2189901203-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FySNjOQdhO6R687cGq3KU%2Fuploads%2FXP2W1YJIglso8dJZFA7v%2FConyard.png?alt=media&#x26;token=864a802d-2120-43ab-ba34-ef22d53d8820" alt=""><figcaption></figcaption></figure>

The construction yard module when activated will allow a player to build new strongholds that can then be used or sold on the market. Building a stronghold will require a blueprint and other resources as well.
