SOS is a pen and paper game for 2-4 players, similar to Tic Tac Toe, but with greater complexity.

Players take turns adding an "S" or "O" to a random space. Spaces cannot be reused on the same turn. Each player must try to create a straight S-O-S sequence either diagonally, horizontally, or vertically. IF a player completes a sequence on their turn, they make another move. But if not, the other player makes the next move.

The game ends once all the boxes in the grid have been filled. The player who gets to make the most number of SOS wins the game.