The Story
Where it came from, and why it turned out this way.
OriginMerels existed in Roman times; enormously popular in medieval Europe
A game scratched into everything
Nine Men's Morris is among the oldest and most widely distributed games in Europe. A related game called merels existed in Roman times, and in the Middle Ages boards turn up everywhere: scratched into church pews, cloister benches, and castle steps. The frequently cited board on a roof slab at the temple of Kurna in Egypt, usually dated to 1400 BCE, is doubtful — marks on a roof slab could easily have been cut by later workmen. What is safe to say is that the game existed by Roman times.
Three phases are really three games
The placement, movement, and flying phases play like three different games. Placement is a positional problem about claiming intersections; movement is a scheduling problem constrained by adjacency; and flying suddenly removes the constraint and becomes an open search. Very few traditional games change their rule shape so completely within a single game — and the trigger is being reduced to three pieces, meaning the closer you come to losing, the more freedom of movement you acquire.
The double mill pushes one rule to its limit
"Form a new mill, remove an enemy piece" is a plain enough rule, but its extreme form is brutal: place one piece so it belongs to two mill lines that each need only that point, then shuttle it back and forth, forming a mill and capturing on every single move. That is the double mill. The entire placement phase of a Morris game is essentially about engineering one while preventing your opponent from doing the same.
Solved in 1993
The Swiss researcher Ralph Gasser fully solved Nine Men's Morris around 1993 using retrograde analysis: with best play from both sides the game is a draw. It was among the first classic games to be cracked outright, more than a decade before checkers. What is striking is how little the result affects practical play — the margin for human error remains wide, and double mills go on deciding games every day.
- The name Morris has nothing to do with morris dancing; it is generally traced to the Latin merellus, meaning a token or counter.
- Three pieces grants flying, but falling below three loses immediately — three is simultaneously the most mobile state and the last line of defense.
- The four four-way points on the middle ring (numbered 5, 11, 14, and 20 on this page) each have four neighbors and are the most mobile squares on the board, while the four corners have only two and most easily become dead pieces.
Complete Rules
Start with what a turn allows and how the game is won.
- Points
- 24 intersections, 16 mill lines
- Stones
- 9 per player, White places first
- Winning conditionreduce your opponent to fewer than three stones, or leave them with no legal move on their turn, and they lose. Note that both conditions only take effect after the placement phase has finished completely.
- Placement phaseplayers alternate putting their nine stones on any empty points, eighteen moves in total. Forming a mill during placement captures just as it does later — you do not have to wait for the movement phase.
- A mill is three stones of one color filling one of the lines drawn on the board: the three points along each side of the three squares, plus the three points on each of the four spokes, sixteen lines in all. Only a mill formed on the current turn triggers a capture — a mill that simply sits there does not capture every turn.
- When capturing you must take an enemy stone that is not part of a mill; only when every one of your opponent's stones is in a mill may you take any of them. The capture belongs to the same turn as the move, the interface highlights the valid targets, and the turn is complete only once you click one.
- The movement phase begins after both players have placed all nine stones, and each turn slides one of your stones along a drawn line to an adjacent empty point. There are no diagonals on the board and no point at the very center; the four spokes connect only the middle ring to the outer and inner rings.
- The flying phase applies per player: as soon as one player is reduced to exactly three stones, that player may move a stone to any empty point each turn, free of the adjacency restriction. Their opponent, with four or more stones, still has to slide along the lines.
Your First Game
Use this order of thought to get through a complete game quickly.
- In the opening, prioritize the four four-way points of the middle ring — points 5, 11, 14, and 20 in the interface. Each has four neighbors, giving the highest mobility and the lowest risk of being blocked in, while the four corner points have only two neighbors and most easily become dead stones.
- When placing, prefer the intersections of two lines so that one stone participates in two potential mills. That is worth more than dutifully lining up a mill that is already complete.
- Do not cram all nine stones onto one half of the board. An advantage in the placement phase means nothing, and being blocked in by your own stones once the movement phase begins is a loss just the same.
- How to playin the placement phase, click an empty point directly. In the movement phase, click one of your stones and then a highlighted adjacent point. After forming a mill the board switches to capture selection, and clicking a highlighted enemy stone completes the turn — undo at that moment cancels the incomplete action.
- Before capturing, check two things: which of your opponent's stones is one move away from a mill, and which one is the shared pivot of two of their mill lines. Casually taking an isolated corner stone usually wastes the opportunity.
Practical Strategy
Move from knowing the rules to playing with a plan.
- The double mill is the central technique: put one stone in two mill lines that each need only that one point, and shuttle it between the two, forming a mill and capturing on every single move. The most direct arrangement on this board is occupying points 1, 3, 4, and 6 and shuttling a fifth stone between points 2 and 5.
- Even a single mill can be opened and closed: move one stone out of the mill and back in next turn, capturing reliably every two turns. Move it in a direction your opponent cannot occupy, or you will not be able to return and will have dismantled a mill for nothing.
- When you are ahead, prefer blocking over continuing to capture. Reducing your opponent below three stones is one way to win, but leaving them with no legal move on their turn is another, and squeezing their stones into corners is often faster.
- Capture priorityfirst dismantle the pivot of your opponent's double mill, then break a line where they are one stone short, and only then consider taking their most mobile stone. Taking a stone that is part of a mill is available only when every one of their stones is in a mill.
- When you fall to four stones, plan the placement of your final three in advance. Dropping to three grants flying, and the flying side can often turn the game around with a run of consecutive mills.
Winning and Special Rules
Details that are easy to miss but can change the result.
- Losing conditions apply only after the placement phase is completely over: a player with fewer than three stones, or with no legal move on their turn, loses.
- There are two kinds of draw: the third occurrence of the same position, including the side to move and both players' stones still to place, and one hundred consecutive moves with no capture.
- Being reduced to three stones grants flying, but falling below three loses immediately, so three stones is simultaneously the most flexible state and the last line of defense.
- Points are numbered 1 through 24, and both the master hints and the position notes use those numbers to describe destinations and capture targets. The four four-way points of the middle ring are 5, 11, 14, and 20.
Common Mistakes
The traps new players fall into most often.
- Assuming a mill captures every turn as long as it stays intact. Only a mill newly formed on the current turn triggers a capture.
- Forgetting to click a capture target after forming a mill and assuming the turn is over.
- Focusing only on your own lines during placement and letting your opponent take two points on the same line, after which every move you make is a forced block.
- Taking the most convenient isolated corner stone and leaving the pivot of your opponent's double mill on the board.
- Reaching the movement phase and only then discovering that your own stones block each other, with no legal move available and an immediate loss.