Ataxx is a two-player abstract strategy board game played on a 7x7 grid. The object of the game is for a player to have a majority of the pieces on the board at the end of the game, by converting as many of their opponent's pieces as possible.
Each player begins with two pieces of either yellow or red. The game starts with all 4 pieces in the 4 corners of the board, with yellow on the top left and bottom right and red on the other two corners. Yellow starts first.
During their turn, players move one of their pieces either one or two spaces in any direction to an empty slot. Diagonal distances are equivalent to orthogonal distances, e.g. it is legal to move to a slot whose relative position is two squares away both vertically and horizontally. A piece can also be moved 2 slots in a L-shaped jump, identical to a knight move in Chess. If the destination is adjacent to the source, a new piece is created on the destination slot. Otherwise the piece on the source moves to the destination. After the move, all of the opponent pieces adjacent to the destination square are converted to the color of the moving player.
Players must move unless no legal move is possible, in which case they must pass.
The game ends when all squares have been filled or, one of the players has no remaining pieces. The player with the most pieces wins.