Nine Men's Morris

Nine Men's Morris (also known as Merels, Mill, or Cowboy Checkers) is a classic two-player strategy game. Form mills of three men in a line, remove your opponent's men, and leave them with too few pieces — or no legal move.

Win by reducing your opponent to two men (they can no longer form a mill) or by blocking every one of their remaining men so they have no legal move.

The board starts empty. Each player's nine men wait off the board and are placed one at a time.

Players take turns placing one man onto any vacant point. If a placement forms a mill — three of that player's men in a continuous straight line, horizontally or vertically — that player immediately removes one opponent man. A man that is itself in a mill cannot be removed unless every opponent man is in a mill.

Placing continues until all 18 men are on the board.

Once every man is placed, a turn consists of sliding one of your men along a line to an adjacent vacant point. Forming a mill still lets you remove an opponent man, under the same mill-protection rule. You may break a mill by sliding a man out of it and remake that mill on a later turn to remove another man.

When a player is reduced to exactly three men, those men may fly: they jump to any vacant point, not only an adjacent one. The other player keeps sliding normally until they also have three men.

Flying is the usual modern rule. The lobby option Flying (on by default) turns it off for the older adjacent-only variant.

You win when your opponent:

After 300 moves the game is a draw, so a mill-dancing loop cannot run forever. The count includes every place, slide, fly, and mill removal — not only turns that capture.