In this game, players take on the roles of competing architects overseeing the construction of a magnificent cathedral. Each turn, they place tiles to enlarge the cathedral and create areas of a single color while placing builder pawns to gain advantages and control areas. In addition, players execute orders to move or remove builders, increase abilities, block spaces, or tear down previously built cathedral parts. There are four tile colors in the game. Players' goals are to create the largest possible areas representing a single color and to have more pawns in these areas than their opponent.

Basilica designed by Łukasz M. Pogoda was first published in 2010 and further developed by the expansion Festum Fatuorum in 2012. The new edition by Portal Games includes the base game with a revamped game board, premium custom-made wooden pawns depicting medieval characters, and the expansion, offering players a premium full game experience.