SOS
Only two letters go into the cells — S and O — and every line of S-O-S scores for whoever's letter completed it.
The game looks like noughts and crosses and works the other way round. There are two letters as well, but they belong to nobody: each player writes either of them — S or O — and the point goes to whoever's letter completed a of S-O-S.
Because of that no cell is "yours". An O once placed waits for somebody to write two S's around it, and it will go to whoever does it first. The game is not about territory but about being last into somebody else's arrangement.
The other consequence is the value of an extra turn. One letter can close two or three lines at once when it stands at a crossing, and at the end of a game, as the grid fills, such cells decide everything.
Rules of SOS
The grid
A square grid. The size is chosen before the start: the larger it is, the longer the game.
A turn
The player writes one letter — S or O, as they choose — into any free cell. The letters are shared: both are available to both players.
A line
If after the turn the grid holds an S-O-S in three consecutive cells — horizontally, vertically or diagonally — the player scores a point for it and marks it with a stroke.
One turn may close several lines at once; each scores its own point.
The extra turn
A player who made at least one line moves again. Turns continue until one of them scores nothing.
End of the game
The game ends when every cell is filled. The higher score wins; equal scores are a draw.
Worth knowing
The size of the grid is chosen before the game, and whether the number of cells is odd or even decides who has the last turn. Whether a scoring turn earns another is where descriptions differ — without that rule the game is markedly quieter. A tie is a tie for some and replayed by others.
Glossary of terms
- A line
- Three cells in a row reading S-O-S, horizontally, vertically or diagonally.