Twelve Men's Morris is a traditional board game similar to Nine Men's Morris. It was most popular during the Middle Ages when it was played in courts across Europe. It is played on a board with 24 nodes joined by lines; each player has twelve pieces. The game proceeds in three phases: Players alternately place one piece on a node in each move. If a player makes three in a row, he or she can capture one of the opponent's pieces. Once all the pieces are placed, players take turns moving the pieces to adjacent nodes. Again, whenever a player forms three in a row, one of the opponent's pieces may be captured. When one player is down to just three pieces, the remaining pieces may "fly" to anywhere on the board (not just adjacent nodes). You win when you reduce your opponent to two pieces, or when he or she can't move. Two possible boards exist. One has three concentric squares marked with the mid-points of the adjacent sides of the the squares linked and also the adjacent corners linked. This is known as "small board Twelve Men's Morris". The other board has four concentric squares marked, and similar to Nine Men's Morris, has only the mid-points of the adjacent sides of the the squares linked. This is known as "large board Twelve Men's Morris".