Ozone is a 3 in-a-row game. Players take turns placing blocks. When you place a block you can score any combos caused by that block's creation. A combo must include the block just placed, and consists of adjacent blocks when viewed from any of the 5 possible directions (like in Rumis or Pueblo) - the blocks must LOOK adjacent, not necessarily be adjacent. The rules variations differ only in which combos score. There are rules for two different games - OZONE and 3NOZO. In OZONE they score for each OOO or O3 combo that they create themselves. In 3NOZO one player scores for OOO and O3 combos, while the other scores for NNN, N3, ZZZ, NZZ (Ns and Zs are functionally equivalent), but in this case they score for combos created by either player.