Ataxx rules

Ataxx is a turn-based game on a square grid. These are the complete rules, from moves to the end of the game.

The board and the pieces

The classic board has 7x7 squares. The players are x, who moves first, and o. Each starts with two pieces in opposite corners. Some variants use other board sizes, up to 9x9, or blocked squares that can never be occupied.

Starting position of the 7x7 board.

Your move

On your turn you choose one of two moves.

Clone: place a new piece on an empty square next to one of your pieces (diagonals included). The original piece stays where it was.
Jump: move one of your pieces to an empty square exactly two squares away. The square it left becomes empty. A jump flies over anything in between.

Clone: the highlighted square is next to the piece, which stays in place.

Jump: the piece goes to the highlighted square, two away, and leaves its origin empty.

Converting pieces

After a clone or a jump, every enemy piece on the eight squares around the destination turns to your colour. Only the neighbours of the destination count: there are no chain reactions.

Before: you are about to clone onto the highlighted square.

After: the three neighbouring enemy pieces are now yours.

When you cannot move

If you have no possible move, you pass. You may only pass when no other move exists. If neither player can move, the game ends.

Blocked squares

Some maps have blocked squares. They are never occupied or converted and do not count as empty squares, but they do not stop jumps.

A map with four blocked squares.

End of the game

The game ends when one of these happens:

One player has no pieces left.
The board is full, meaning there are no empty squares.
Neither player has a possible move.

In these cases the player with more pieces wins; equal counts are a draw. Two more rules prevent endless games, and both end in a draw: one hundred half-moves in a row without a single clone, or the same position, with the same player to move, appearing three times.