Master of Fortresses is a fortress defence game inspired by classic tower defence games and castle defence games like Rampart. Taking command of a european fortress in the age of black powder warfare as one of three factions (Britian, Prussia or France), the player must earn funds by weathering successive onslaughts of attackers and use this money to repair and expand his fortress. Strategic placement of walls and bastions are key, as is the timing and use of traps like the Trou-de-Loup or the exploding siege mine.