Another name for this game is Merrills (Diehl and Donnelly 70). It was a very popular game played by all levels of Medieval society. It could be played almost anywhere as long as there was somewhere to place a ready-made game board or draw the diagram of the board in the dirt. The game pieces ("morrells") could be anything (pieces carved from wood or ivory, ordinary stones, etc.) as long as there were nine of them for each player and the pieces for each side were different enough in shape or color for the players to tell them apart. Sometimes, the game was even played outside on a large board with real people for playing pieces (Cosman 55-56). Nine Men's Morris is still played by people today.
Object: To eliminate the morrells of your opponent until he or she has only two left.
Equipment: Nine Men's Morris board (printable) and two sets of 9 pieces (each a different color or design so you can tell them apart, I used circles cut from colored paper)
The rules come from Medieval Celebrations by Daniel Diehl and Mark Donnelly (pp. 70-71).
The basic design of the board looks like this:
This is a picture of a game in progress:
Placing Pieces: Start with the board completely empty. Each player has a set of nine morrells (playing pieces). Take turns placing your morrells, one at a time, on the board at the points marked by the dots until you run out of morrells. No space can have more than one morrell, and there will be some spaces empty. Some strategy is involved in the placing because each of you will be trying to get three of your morrells in a row, which known as a mill. You can try to get three morrells in a row while placing them on the board, but your opponent will try to block you. You should try to block your opponent from getting three in a row as well because that is how players can remove each other's pieces from the board.
Making Mills: When you get three of your morrells in a row, you can take one of your opponent's morrells off the board. You cannot remove morrells that are currently part of a mill, but other than that, you can remove any piece you choose. Diagonals do not count in forming mills; they must be in straight lines, following the black lines of the board.
Tip: When deciding which of your opponent's pieces to remove, check to see which of his pieces are in the best position to help him make a mill and take one of them. That way, you can keep him from taking one of your pieces.
Moving Pieces: When all the morrells are on the board and no one has any mills, you and your opponent take turns moving one of your morrells to an adjacent empty space. You can only move one morrell per turn, and a morrell only moves one space at a time. You are allowed to move one of your morrells out of a mill on one turn and back in again on the next turn, provided that your opponent hasn't removed one of the pieces needed to make the mill on his turn or moved one of his pieces to block yours.
Winning: Players continue moving their morrells in this way, and a morrell is removed every time a mill is made or remade until one player either can't move at all because his morrells are blocked in (in which case, he loses the game) or he has only three morrells left. When someone is down to only three morrells, that player can move one of his morrells to any empty space on the board on his turn, no matter where that morrell starts from. He doesn't have to follow the lines on the board at all when moving. The other player moves normally, unless he also has only three morrells left. The winner is the one who manages to reduce the opponent to only two morrells so he can't create any more mills.