Nine Men's Morris · Rules guide
Nine Men's Morris rules: how to play
Place nine men, slide them along the lines, and take an enemy man every time you close a mill — plus the open mill that wins games, and the flying rule that saves them.
The short answer
- The board has 24 points; each player places nine men, then slides them along the lines.
- Three in a row is a mill, and closing one removes an enemy man permanently.
- You may not take a man standing in a mill unless all of their men are in mills.
- An open mill — breaking and re-forming a mill each turn — takes a man every single turn.
- A player reduced to three men may fly to any empty point; two men loses.
The board and the three phases
Nine Men's Morris is played on a board of 24 points — three nested squares joined by four crossbars. Each player has nine men, and the game has three distinct phases that feel like three different games.
- Placing. Players take turns putting men on empty points until all eighteen are down.
- Moving. After that, a turn is sliding one man along a line to an adjacent empty point.
- Flying. A player reduced to three men may jump to any empty point.
Mills: three in a row
Three of your men in a row along one line is a mill. Whenever you complete one — in either phase — you immediately remove one of your opponent's men from the board, for good.
Which man you may take
You may not take a man that is standing in a mill — unless every one of your opponent's remaining men is in a mill, in which case any of them may be taken.
The open mill
The most important tactical idea in the game: a mill that you break and re-form counts again every time. Two mills sharing a man — so that moving one man back and forth opens one and closes the other — is called an open mill or a running mill, and it takes an enemy man every single turn. Building one usually wins the game on the spot.
Winning and drawing
You win when your opponent is reduced to two men — too few to form a mill — or when they have no legal move at the start of their turn.
Flying
With only three men left, a player may move to any empty point rather than to an adjacent one. This gives the losing side real drawing chances, because three flying men can build a mill from anywhere. Some traditional rule sets omit flying entirely, which makes the game much harsher for the player who falls behind.
Draws
Games are drawn by agreement, by threefold repetition, or under a move limit when neither side can make progress. Between strong players, draws are the normal result — the game was solved by computer in 1993 and proved to be a draw with perfect play.
| Rule | Standard | Common variation |
|---|---|---|
| Flying at three men | Allowed | Omitted — harsher for the trailing player |
| Taking from a mill | Forbidden unless all men are in mills | Sometimes always allowed |
| Removing during placement | Yes, mills count immediately | Same |
| Board size | Nine men, 24 points | Three, Six and Twelve Men's Morris exist too |
Three, Six and Twelve Men's Morris
Morris is a family of games on progressively larger boards:
- Three Men's Morris — a 3×3 board, essentially noughts and crosses with movement. Solved and drawn.
- Six Men's Morris — two squares, no crossbar centres, six men each. Popular in medieval Italy and France.
- Nine Men's Morris — the standard game described here.
- Twelve Men's Morris — adds the four diagonals, giving more mills and a much more crowded board. Common in the American South and in parts of Africa and South Asia.
Common questions
Can you take a man from a mill?
No, not while your opponent has any man outside a mill. If every one of their men is in a mill, you may take any of them.
What is an open mill?
Two mills sharing a man, arranged so that moving one man back and forth breaks one mill and closes the other. It removes an enemy man every turn and usually decides the game.
Do you move along the diagonals?
Not in Nine Men's Morris — only along the marked lines. The corner points connect around the squares and through the crossbars, never diagonally. Twelve Men's Morris adds diagonals.
What is flying in Nine Men's Morris?
When a player is down to three men, they may move to any empty point instead of an adjacent one. It gives the losing side real chances, and some traditional rule sets leave it out.
How do you win Nine Men's Morris?
By reducing your opponent to two men, which makes a mill impossible, or by blocking them so they have no legal move at the start of their turn.
Is Nine Men's Morris solved?
Yes. Ralph Gasser solved it in 1993: with perfect play by both sides the game is a draw.
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