Defeat the opposing sumo wrestler ("Rikishi") by knocking him off the bridge ("dohyo", fighting space). You can also win by being furthest advanced on the dohyo when the last tile is drawn. There's a deck of numbered tiles, like playing cards. Each player has five tiles in their hand. Players alternate playing tiles to move or attack until a Rikishi is knocked off the dohyo or the draw pile is exhausted. You can attack with multiple tiles to increase the intensity of the attck. Source: The Developer Website.