This game is an adaption of the Chinese board game Mahjong. The basic playing principle (the game uses the official British rule set): the basic pool consists of 144 playing stones with different motives. Every player receives 14 out of them. With every turn, players remove one of the stones and other players can take them (but only if they can use it to shape certain patters with the stones already in their possession). The winning condition is to create the "Mah Jong" stone combination. Colossus Mah Jong is designed for one player (the AI controls the other three players) and offers various possibilities to adjust the game, like nine difficulty levels, hidden piles or a tournament mode. Two functions are for new players: the computer gives advice when reaching a complicated situation and there is a separate tutorial program included.