Game consists mainly of a 3x3 gameboard and lots of different transparent perspex tiles with 1-5 dots (also printed somewhere in a 3x3 grid) on them. Players try to form stacks of tiles and score the visible points. Main rule is that you aren't allowed to place a dot on top of another dot. On each turn the player has the choice of starting a new stack using one or more of his tiles or to upgrade an existing stack. If you manage to complete a 9-dot-stack you can continue placing tiles. Play until all tiles are used or nobody can play. Highest score wins - that's it! Identical in materials but different in rules is Hi-Spot/Stack-Ominos.