Description of 12 Men's Morris Free Version
Each player starts with nine twelve pieces ("men"). At the start of the game, there are no pieces on the board. The pieces may rest at any dot on the board, where the lines intersect. The object of the game is to capture all but two of the opponent's pieces.
Players alternate turns. In a turn, the player may either place a piece on the board, or move a piece that is already on the board. A piece may be placed at any open position on the board. A piece may be moved along a line on the board to the next unoccupied position.
Players capture the opponent's pieces by forming "mills." A mill is three pieces of the same color in a row, along a board line. For each mill formed, the player may capture one opponent's piece; it is removed from the board and cannot return, in which case two pieces are captured. To prevent a single mill from being a decisive advantage, a mill is not counted if it is formed by moving a piece from a mill and moving it back in the immediately following turn.
When one player has two or fewer pieces left to place or on the board, the game is over, and that player has lost.