In Nine Man's Morris—one of the most common dark ages board games—players attempt to remove each other's pieces from the board until one player is left with only two pieces. Whenever a player places three pieces in a row, he may remove one of his opponent's pieces.
Each player begins with nine "men" (hence the name). Players place their pieces on the board alternately until both have placed all their pieces. If a player creates a row of three pieces (following the lines on the board-diagonals are not permitted), he may remove one of his opponent's pieces. When removing pieces, a row of three may not be broken unless there are no other pieces available. Pieces removed from the board are out of the game.
Once all the pieces have been placed on the board, players begin sliding them to try and form rows of three. Pieces may slide along the lines on the board, one space at a time, and may only move to a position which is not already occupied. Players try to prevent each other from forming rows of three, while trying to form rows themselves. There is nothing to stop a player from moving one piece out of a row and then back in again other than the other player moving a piece in first.
The game ends when one player cannot move any of his pieces or is reduced to two pieces, and is therefore no longer able to form rows.
There is a related game, played with essentially the same rules, called Twelve Man's Morris.
