Nine Men's Morris
Place, move, then fly. Solved as a draw in 1993 — so every decisive game comes from a mistake rather than the opening.
Flying is what saves the losing side
The game has three phases. You place nine pieces, then slide them along the lines to adjacent points, and once you are down to exactly three you may move to any empty point on the board. That last rule is what stops the endgame being a formality — a player reduced to three pieces is dangerous precisely because the board no longer constrains where they can go.
Nine Men's Morris was solved by Ralph Gasser in 1993 with a full retrograde analysis, and the result is a draw. Perfect play by both sides ends level, so every decisive game comes from a mistake rather than from the opening — which is worth knowing before blaming the pieces. One detail people often play wrongly: a piece sitting in a mill cannot be captured while its owner has any piece outside one, and only when every remaining piece is milled does that protection lapse.
How to use
- Place your nine pieces one at a time on any empty point.
- Then slide pieces along the lines to adjacent empty points.
- Three in a line is a mill — take one of your opponent pieces.
- Down to three pieces, you may fly to any empty point at all.
Frequently asked questions
How do you play Nine Men's Morris?
In three phases. First both players place nine pieces alternately on any empty point. Then they slide pieces along the lines to adjacent empty points. Whenever you line up three of your own pieces on a marked line you form a mill and remove one of your opponent pieces. A player reduced to two pieces, or unable to move, loses.
What is a mill?
Three of your pieces in a row along one of the sixteen marked lines. Forming one lets you remove an opposing piece immediately, and you can break a mill and reform it on a later turn to remove another — repeatedly opening and closing the same mill is a standard and very effective technique.
Which pieces can I capture?
Any opposing piece that is not currently part of a mill. If every one of your opponent pieces is in a mill, then the protection lapses and you may take any of them. Getting this exception wrong is the commonest rules error in the game, and it matters because it decides many endgames.
What is flying?
Once you are reduced to exactly three pieces you may move any of them to any empty point rather than only to an adjacent one. It is what stops the endgame being a formality for the player ahead, because a player on three pieces can suddenly reach anywhere and threaten mills that the board would otherwise prevent.
Is the game solved?
Yes. Ralph Gasser proved in 1993, using a full retrograde analysis, that Nine Men's Morris is a draw with perfect play. That is worth knowing before you play, because it means every decisive result comes from a mistake somewhere rather than from an inherent advantage to either side.
What is a good placing strategy?
Take the four-way intersection points rather than corners, because mobility decides the middle game and corners have only two neighbours. Aim to build a double mill — two mills sharing a piece, which can be opened and closed alternately to remove a piece every single turn — and watch for your opponent doing the same.
What is a double mill?
Two mills arranged so that moving one piece back and forth opens one and closes the other. It removes an opposing piece every turn for as long as it lasts, and it is usually decisive. Preventing your opponent from arranging one is worth more than forming a single mill of your own.
How do you win the endgame?
By keeping your opponent short of moves. A player who cannot move loses outright, so blocking is a winning method in its own right, and it becomes more powerful as the board empties. Against a player who is down to three and flying, blocking stops working and you have to win on material instead.
How old is the game?
Very. Boards have been found cut into the roofing slabs of the temple at Kurna in Egypt, and it was widely played in the Roman empire and across medieval Europe — boards are carved into cloister seats in several English cathedrals. It is among the oldest board games still played in essentially its original form.
What else is it called?
Merels or merrills in English, Mühle in German, Molino in Italian and Nine Man Morris in older English sources. Variants with three, six and twelve pieces exist, and the twelve-piece version adds diagonal lines, which changes the game considerably by creating far more possible mills.
How strong is the computer opponent?
It looks one move ahead including the capture that follows a mill, and values material, mills and mobility. That is enough to punish loose play and to take mills whenever offered, but it does not plan double mills several moves out — which is the skill that beats it.
Does the game save my progress?
No. Everything runs in your browser, nothing is stored or uploaded, and closing the tab loses the current position.
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