Three Men's Morris

This ancient game is probably a direct ancestor of the better known Nine Men's Morris as well as Tic-Tac-Toe. It is played on a board of three rows and three columns. Players have three pieces each and take turns first placing then moving their pieces. The goal is to form a straight or diagonal line of three. There are two forms of the game: In the simple version, diagonal moves are illegal; in the more complex variant they are allowed.