Golden Keys

Overview
Golden Keys are a rare resource in the game alongside the less common Ruby Keys. Their main usage is to construct Special buildings. Most buildings also require a Golden Key every 5 levels when upgrading, if such upgrade is possible.

Every time the player levels up, they earn one Key, and two every 5 levels. 3 Ruby Keys can be exchanged for 2 Golden Keys if desired. The Pawnshop building allows you to deposit Golden Keys for hourly profit, or to withdraw extra Keys and pay fees until the Keys are deposited back. You may also exchange Golden Keys for permanent extra building slots here.

Obtaining and general usage: See table on the Resources page.