In The Game of Triangles, tiles are played so the numbers on each side match the numbers on any adjoining tiles.

Players begin their turn by declaring what number they will play on. They continue to place the triangular tiles until they have no remaining tiles with that number that can be placed. Tiles are then drawn to bring the total back up to 5. Scoring is based on the numbers on the placed tile, with multipliers for placements involving two or three adjoining sides.