Boss Monster: Rise of the Minibosses is a large expansion set for Boss Monster that can be played on its own or combined with earlier Boss Monster sets and expansions. Rise of the Minibosses adds a new mechanic to the game which allows players to collect Coins by using their Rooms and Spells. Coins can then be used to upgrade rooms or hire the new Minibosses. Minibosses provide permanent bonuses to improve the players dungeon rooms. Also included are new Bosses, spells, and heroes.