Ataxx is an abstract strategy board game that involves play by two parties on a seven-by-seven square grid. The object of the game is to make your pieces constitute a majority of the pieces on the board at the end of the game, by converting as many of your opponent's pieces as possible.
Each player begins with two pieces, black and white, for the first player and second player respectively. The game starts with the four pieces on the four corners of the board, with black in the top left and bottom right and white on the other two. Black moves first.
During their turn, players move one of their pieces either one or two spaces in any direction. Diagonal distances are equivalent to orthogonal distances, e.g. it is legal to move to a square whose relative position is two squares away both vertically and horizontally. If the destination is adjacent to the source, a new piece is created on the empty departure square. Otherwise the piece on the source moves to the destination. After the move, all of the opponent player's 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 board will be altered by having certain squares filled (not playable by either player), 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.
Play with machine AI or play with others over internet.