The game proceeds in two phases:
placing men on vacant points
moving men to adjacent points

Phase one: placing pieces


Nine Men's Morris starts on an empty board.
The game begins with an empty board. The players determine who plays first, then take turns placing their men one per play on empty points. If a player is able to place three of his pieces in a straight line, vertically or horizontally, he has formed a mill and may remove one of his opponent's pieces from the board and the game. Any piece can be chosen for the removal, but a piece not in an opponent's mill must be selected, if possible. Once all pieces have been placed, phase two begins.

Phase two: moving pieces
Players continue to alternate moves, this time moving a man to an adjacent point. A piece may not "jump" another piece. Players continue to try and form mills, and remove their opponent's pieces in the same manner as in phase one. A player may "break" a mill by moving one of his pieces out of an existing mill, then moving the piece back to form the same mill a second time, or any number of times; and each time removing one of his opponent's men. The act of removing an opponent's man is sometimes called "pounding" the opponent.