Win by moving a snake to the opposite corner. Snakes move any number of spaces along the forward diagonals and capture by replacement.
 
The principal game strategy consists of getting under your opponent's defenses. This happens when you move a snake onto a diagonal that is behind most of your opponent's snakes. The opponent can defend only by moving snakes out from the snakepit area (the home corner), which substantially weakens the opponent's defense. The converse of this strategy is that you should try to keep a snake in your snakepit, with other snakes close by, as long as possible.
 
As in the games Breakthrough and Ugly Duck, also available on Zillions, the forward orientation of the pieces means that games develop quickly and draws are impossible.
 
Sidewinder comes in two board sizes, one with four hexes to a side, the other with five.