The Vault stores gold and wood, as well as stone and iron when upgraded. The enemy cannot steal resources stored inside the Vault. The Vault will also protect 48% of resources outside of it.
Vault Tips
The Vault protects your Resources from enemy attacks. It keeps an percentage of your resources safe, even if your headquarters is destroyed.
Upgrade your Vault to keep more of your resources protected.
By clicking on the Resource icons in the top of your screen you are able to see exactly how much resources are ‘Protected by vault’.