Nine Men's Morris

How to play Nine Men's Morris

Nine Men’s Morris — also known as Mills, Merels or simply the mill game — is one of the oldest strategy board games in the world. Boards have been found scratched into Roman roof tiles and the cloisters of medieval cathedrals, and the game is still played today because its rules are simple while its tactics run surprisingly deep. Two players — Blue and Amber in this version — each command nine men on a board of 24 points. The game flows through three distinct phases: placing your men, sliding them along the lines, and finally flying when you are down to your last three. Line up three men and you close a mill, which lets you remove an enemy piece from the board. Play a friend on the same screen, or challenge the computer at three difficulty levels.

The goal

Reduce your opponent to two men, or block them so completely that they cannot make a single legal move on their turn. You do this by forming mills — rows of three of your own men along a drawn line of the board — because every new mill you close lets you remove one enemy man from the game for good.

The board

The board is three concentric squares connected by four short lines at the midpoints of their sides. That makes 24 points — the corners and mid-edge spots — where men can stand, joined by the lines along which they may later move. There are exactly 16 possible mill lines: the twelve sides of the three squares plus the four connector lines. Diagonals do NOT count — three men across a corner is not a mill. Blue always makes the first move.

The three phases

Every game of Nine Men’s Morris moves through up to three phases. The indicator above the board always shows the phase the current player is in.

• Phase 1 — Placement. Starting with Blue, the players take turns placing one of their nine men on any empty point, for 18 turns in total until both players have placed all nine. If you complete a row of three during placement, that already counts as a mill and you immediately remove an enemy man. Where you drop your men in this phase largely decides the middle game, so place with a plan.
• Phase 2 — Movement. Once all men are placed, a turn consists of sliding one of your men along a drawn line to an adjacent empty point. No jumping and no diagonals — just one step along a line. If your move closes a mill, you again remove an opposing man. Watch your mobility: a man with no empty neighbours cannot move at all.
• Phase 3 — Flying. When a player is reduced to exactly three men, their pieces may fly: instead of sliding to an adjacent point, they may move to ANY empty point on the board. Flying is a comeback mechanism — with three men you are one removal away from defeat, but the freedom to land anywhere makes your mill threats very hard to prevent.

Mills and removing men

A mill is three of your men standing on one straight drawn line of the board. The moment you close a mill — whether by placing or by moving — you must remove one enemy man of your choice. The removed man leaves the game permanently; it is not returned to the opponent’s hand.

There is one important restriction: men that stand inside a completed enemy mill are protected. You must pick a man that is not part of any mill — only when every single enemy man stands in a mill may you break into one. The game highlights the men you are allowed to take with a red ring.

You may open a mill by moving a man out of it and close the same line again on a later turn — every re-closing counts as a new mill and earns another removal. Building a swinging double mill, where one move opens one mill while closing another, is the strongest formation in the game.

Winning and losing

You win in either of two ways. Reduction: when your removals leave the opponent with only two men (after they have finished placing), they can never form a mill again and immediately lose. Blockade: if it is your opponent’s turn and none of their men has a legal move — every neighbouring point occupied — they lose on the spot. A player who can still fly can never be blockaded, so blockade wins happen while the opponent has four or more men. If 40 consecutive moves pass without any man being placed or removed, the game is declared a draw.

Playing the computer (ranked)

In “Nine Men’s Morris vs Computer” you pick your colour and a difficulty — Easy, Normal or Expert. The computer thinks entirely on your device, so it works offline. Beat it to earn ranking points: Easy +10, Normal +30, Expert +100. Sign in and your best results appear on the leaderboard.

Strategy tips

• During placement, prefer the four cross points of the middle square — the ones with four connections. They join the most lines and give you the most flexible mill threats later.
• Don’t chase your first mill at any price. It is often better to build two mill threats at once — your opponent can only block one of them.
• Block early. If the opponent has two men on a line, occupying the third point costs you little and saves you a piece.
• Aim for a swinging double mill: two mills sharing men, where one move opens one mill and closes the other. Each swing removes another enemy man.
• In the endgame, count mobility, not just men. Trapping enemy men in a corner can win by blockade even when material is equal.

Frequently asked questions