Nine Men's Morris: the classic mill game

Nine Men’s Morris, free online

Nine men’s morris is a two-player strategy game for two sets of nine stones on a board of three squares. You place your stones one by one, then slide them along the lines, and every time you get three in a row you take one of your opponent’s stones. Bring the other side down to two stones, or leave them with no move at all, and you win.

You can play the computer on easy, medium or hard, or choose 2 players and share one phone or computer with a friend. On the start screen you can also switch to six men’s morris and turn the flying rule on or off. The board is drawn as a wooden board with inlaid lines, the stones are white and black, and a mill glows gold when it closes.

How to play here

While placing, tap any empty point. You can also drag a stone from your tray, the row of stones under the board, and drop it on a point. Once all stones are down, drag a stone along a line to a free neighbour, or tap the stone first: the points it can reach light up, and a tap on one of them moves it. Tap the stone again to put it back down.

When you make a mill, the board waits for you to take a stone. The stones you are allowed to take pulse with a red ring, so the rule about stones in mills is shown for you. Tap one and play goes on.

The two chips at the top show how many stones each side still has, counting the ones in hand, and the chip of the player whose turn it is lights up. Undo takes back your last move together with the computer’s answer. Hint asks the hard computer for a move and marks it with a gold ring. Restart deals a new board with the same settings. Against the computer you play White, who moves first, in the first game, and the colours switch every game after that.

When is it a draw?

Two careful players can shuffle stones back and forth for a long time without either side making progress. To keep games from going on forever, this version calls a draw when 50 moves in a row, counting both players, pass after the placing phase without a mill. The status line warns you when you are ten moves away from that limit. Placing moves never count toward it.

A short history

Nine men’s morris is one of the oldest board games still played. Boards were cut into stone in Roman times, and the game was widely played across medieval Europe, where boards are still found scratched into the stone benches and steps of old churches and castles. A board for the game was found in the Gokstad ship, a Viking burial from Norway. Shakespeare mentions it too: in A Midsummer Night’s Dream, Titania complains that the nine men’s morris, a board cut into the turf, is filled with mud.

The English name is usually traced to merels, an old word for the game’s pieces, which is why it is also called merels or merrills. In German it is Mühle, the mill, and that name is used in much of Europe. In 1996 the game was solved by computer, and perfect play from both sides ends in a draw.

Strategy that works

1. Spread out while placing. Stones on the middle square and on midpoints keep more ways to move. A tight clump of stones can be sealed in later.
2. Watch both phases at once. Each stone you place is also a stone you will have to move. Ask whether it will still have a free neighbour when the board is full.
3. Block early threats. Two stones of the same colour on a line with an empty third point are one move from a mill. Stop them unless you can make your own mill first.
4. Open and close a mill. Once you have a mill in the moving phase, slide one stone out and back in to close it again. Each time it closes you take a stone, so your opponent has to block the empty point.
5. Aim for a double mill. A stone that closes a mill whichever way it moves takes a stone every turn. Few positions can survive it.
6. Count moves near the end. With flying on, a player with three stones becomes dangerous, because any two of their stones in a line are a threat that can be closed from anywhere. Keep those points covered.

Levels

Easy makes plenty of loose moves and is a good way to learn the rules. Medium looks three moves ahead, grabs mills and blocks the obvious ones. Hard searches much deeper and plays a strong game in both phases, so you need careful placing and a plan for the moving phase to beat it. For more classic two-player games, try Checkers, Gomoku and Mancala.

How to play Nine Men's Morris

1. The board has 24 points on three squares, one inside the other, joined at the middle of each side. Each player has 9 stones, white or black. White moves first.
2. Placing: the players take turns putting one stone from their hand on any empty point until all 18 stones are on the board.
3. Moving: then each turn you slide one of your stones along a line to a neighbouring empty point. There is no jumping over stones.
4. Three of your stones in a straight line along one line of the board is a mill. When you make a mill, you take one of your opponent's stones off the board. If you make two mills with one move, you still take one stone.
5. You may not take a stone that is part of a mill, unless every one of your opponent's stones is in a mill.
6. Flying: when a player is down to three stones, those stones may jump to any empty point. You can turn this rule off on the start screen.
7. You lose when you have only two stones left, or when it is your turn and you have no legal move.
8. If 50 moves in a row (both players counted) pass after the placing phase without anyone making a mill, the game is a draw.
9. Six men's morris uses two squares, 16 points and 6 stones each, with the same rules. Mills only run along the sides of the squares.

Nine Men's Morris tips

Take midpoints early, not corners

A point in the middle of a side has three or four neighbours, while a corner has only two. Stones on midpoints, and above all on the middle square, can move in more directions and block more of your opponent's lines. Corners are easy to trap once the board fills up.

Don't rush to make mills while placing

A mill made in the first few placements costs your opponent one stone, but it often leaves your stones bunched and stuck. Spreading out and keeping room to move pays off when the moving phase starts, and the stones you placed early decide who can still move.

Build a running mill

The strongest shape in the game is a double mill, sometimes called a running mill. One stone sits between two lines so that each time it moves back and forth it closes a mill, and you take a stone every turn. Watch for two of your lines that share an empty point next to one of your stones.

Keep your stones mobile

Losing because you cannot move is just as final as losing your stones. Count how many free moves you have, and avoid filling in the points next to your own stones. Pressing your opponent's stones into corners can win a game without a single mill.

Block two in a row at once

Two of your opponent's stones on a line with the third point empty is a threat. While placing, block it right away unless you can make a mill of your own first. If your opponent has two threats at once, you can only stop one of them.

Frequently asked questions