Triodi is a game of alignment played in Greece. This version of it includes diagonal lines on the board.
Rules
Three concentric squares, the corners and midpoints of the squares connected with lines. Nine pieces per player. Players alternate turns placing a piece on an empty spot on the board. When all of the pieces are placed, the players alternate turns moving a piece to an empty adjacent spot along the lines. During either phase, when a player places three of their pieces in a row along the lines, the player removes any one of the opponent's pieces. The player who reduces the opponent to two pieces wins.