Nine Men's Morris

How do you play Nine Men's Morris?

Two players, light and dark, each start with nine men in hand. The board has 24 points on three nested squares, joined by lines through the middle of each side. A game has three phases: placing, moving and flying.

In the placing phase you take turns putting one man on any empty point. In the moving phase, once all men are placed, you slide one of your men along a line to a neighbouring empty point. Flying, the last phase, is explained below. Whenever you line up three of your own men on a line, you have formed a mill, and you immediately remove one enemy man from the board.

You win when your opponent is reduced to two men, because two men can never form a mill, or when they have no legal move on their turn. Tap or click a point to place or pick up a man, then tap its destination. Legal points are highlighted, and the game tells you when you must remove a man.

What is a mill, and which men can you remove?

A mill is three of your men in a straight row on one line of the board. The sides of each square count, and so do the four lines that cross from the outer square to the inner one. A man that sits on two lines can be part of two mills at once.

When you close a mill, by placing or by sliding, you remove one enemy man. The rule is that the man you take must not be part of an enemy mill. If every enemy man is in a mill, you may take any of them. Taking a man from a mill-in-waiting is usually the strongest choice, because it breaks the threat before it happens.

What is the flying phase in Nine Men's Morris?

When a player is down to exactly three men, they may fly. Instead of sliding to a neighbouring point, a flying player can jump any one man to any empty point on the board. This gives the weaker side a real chance to fight back, since they can threaten a mill from almost anywhere.

Flying exists in Nine and Twelve Men's Morris. It does not exist in Six or Three Men's Morris, where men always slide. The flying side can only fly while they have three men, and the other side still moves normally unless they are also down to three. Most endgames are decided by whether the stronger side can create two threats at once, so the flyer cannot block both.

What are Three, Six and Twelve Men's Morris?

Morris is a family of games, and our version lets you pick the member you want from the start screen.

• Three Men's Morris: the smallest and quickest. Each side has three men, there is no removal, and the first mill wins the game. Men slide along lines once placed.
• Six Men's Morris: a small board with two squares and six men each. You place, then slide. Mills remove men, and there is no flying.
• Nine Men's Morris: the classic, with 24 points and nine men each. Placing, moving and flying all apply.
• Twelve Men's Morris: the same 24 points as Nine, but with diagonal lines added at the corners, giving 20 possible mills, and twelve men each. If the board fills up completely, the game is a draw. Flying applies when a side is down to three.

Is Mühle the same as Nine Men's Morris?

Yes. Mühle is the German name, which simply means mill, and Moulin is the French name. In English you may also meet Mill, Merels, Merrills, Nine Men's Morris and Cowboy checkers, since the board is easy to scratch into a table or a plank. The rules are the same game, with small regional differences, such as whether flying is allowed.

Unser Mühle folgt den gängigen Regeln, mit Springen bei drei Steinen. Notre jeu du moulin suit les règles classiques, avec le vol à trois pions. The rules we use are described on this page, so you always know exactly what to expect.

How do you win at Nine Men's Morris?

You win by reducing the other side to two men, or by leaving them with no legal move. The second route surprises many beginners: a player whose men are all boxed in loses on the spot, even with plenty of men left.

A draw happens in two ways. If the same position occurs for the third time with the same side to move, the game is drawn by threefold repetition. And if 100 plies, meaning single moves by either side, go by with no mill once every man has been placed, the game is also a draw. In Twelve Men's Morris a completely full board is a draw as well.

What is the best Nine Men's Morris strategy?

Strong players follow a few simple ideas. They are most useful in the placing phase, where the game is often decided.

• Mobility beats material. Do not rush to build a mill if it leaves your men boxed in. Keep as many empty neighbours around your men as you can.
• Take the junctions. Points with four neighbours, the middle points of the middle square, give a man the most options. Corners have only two neighbours and are easy to trap.
• Block first, attack second. If the opponent has two men on a line and the third point is empty, occupy it unless you can win a mill yourself right now.
• Build two threats at once. A fork, two open lines that share one move, cannot be blocked with a single man.
• Do not leave men in an unfinished position. In the moving phase, avoid putting everything on the outer square, where your men can be sealed in.
• Count the flying phase. Before you take your opponent down to three men, check that they cannot fly into a mill straight away.

What is a running mill, or double mill?

A running mill, also called a double mill or a Zwickmühle in German, is the strongest shape in the moving phase. It is two lines that share a man. One of your men slides back and forth between two points: when it sits on one, it completes a mill on the first line, and when it moves across to the other, it completes a mill on the second line. Every single move closes a mill, so you remove an enemy man every turn.

To build one, you need a spare man that can step between two lines. Look for a position where one of your mills is open on a point next to another line that already holds two of your men. To defend, you must occupy the empty point or capture the key man before the shape is ready. Learning to spot your opponent's running mill two moves early is one of the biggest steps from beginner to club player.

Can you play Nine Men's Morris against the computer?

Yes, and there are three levels. Easy makes shallow choices and often misses threats, which is ideal when you are learning the rules. Medium looks several moves ahead and plays sensibly, but it can be outplayed with a good running mill. Hard uses alpha-beta search with special handling of the endgame, and it runs in a Web Worker so the page stays smooth while it thinks.

Whatever level you choose, you can ask for a best-move hint and take back your last move with undo. A hint shows the move the engine thinks is strongest. It is a nice way to learn, but it does not teach you why a move is good, so read the strategy notes above as well.

How do you play Nine Men's Morris with friends?

Choose online play and create a room, then send the room link to your friend by message. When they open it, the game starts, and each of you plays on your own device. You can also hand one phone or computer back and forth for a two-player game on one screen. No account is needed for either, and it is free, in the browser.

Everything works the same online as against the computer, with the same rules, the same variants and the same draws. Games are saved, so you can resume where you left off.

Where does Nine Men's Morris come from?

Boards of this kind are found in many places, and the game has been played in Europe for many centuries. In the Middle Ages it was a favourite, and boards were cut into the stone of cloisters and cathedral steps. Shakespeare mentions the game in A Midsummer Night's Dream, as the nine men's morris filled up with mud.

The oldest claims of Roman or even Egyptian origin are hard to prove, so it is safest to call it ancient. What is certain is that the game is easy to teach, hard to master and cheap to play, which is why it has lasted.