User:Elembis/Nine Men's Morris

Nine Men's Morris is an abstract strategy board game for two players that emerged from the Roman Empire. The game is also known as Nine Man Morris, Mill, Mills, Merels, Merelles, and Merrills in English. It is called Mühle and Mühlespiel in Dutch, Mérelles and Jeu de Moulin in French, Mulino in Italian, Trilha in Portuguese, Naukhadi in west India,, and Mølle and Tria elsewhere.

The number of legal positions in Nine Men's Morris is estimated to be 1010, while the total number of possible games is approximately 1050. In October 1993, Ralph Gasser solved the game, showing that it ends in a draw with perfect play. Gasser also developed an AI player called Bushy which is regarded as the world's strongest player.

Rules and play
Each player has nine pieces, or "men", which move among the board's twenty-four intersections. As in draughts, the object of the game is to leave the opposing player with no pieces or no legal moves.

Placing the pieces
The board is empty when the game begins. Players take turns placing their pieces on empty intersections. If a player places a piece which gives them a line of three pieces on any line drawn on the board, they have a "mill" and may remove an opponent's piece; pieces in mills may not be removed unless all of the opponent's pieces are in mills. Removed pieces may not be placed again. Once all eighteen pieces have been placed, players take turns moving.

Moving the pieces
In a move, a player slides one of their pieces along a board line to an empty adjacent intersection. If they cannot do so they lose the game.

As in the placement stage, a player who moves to align three of their pieces on a board line has a mill and may remove an opponent's piece, avoiding the removal of pieces in mills if at all possible.

Flying
In one variation, once a player is reduced to three pieces, their pieces may "fly", "hop" or "jump" to all empty intersections, not just adjacent ones. Some sources of the rules say this is the way the game is played, some treat it as a variation,   and some don't mention it at all. A "19th century games manual" calls this the "truly rustic mode of playing the game".

Any player reduced to two pieces is unable to remove any more opposing pieces and thus loses the game.

Strategy
In the beginning of the game, it is more important to place pieces in versatile locations than to try to form mills immediately and make the mistake of concentrating one's pieces in one area of the board.

An ideal position, which typically results in a win, is to be able to shuttle one piece back and forth between two mills, removing a piece every turn. For example, in the diagram above, white can win the game even if black moves first.

Variants
{|
 * -valign="top"
 * [[Image:Three Men's Morris board.svg|100px|left]]

Three Men's Morris
Three Men's Morris is played on a three-by-three board with just three pieces per player. Flying is allowed. Diagonal lines are sometimes added to the board, reminiscent of tic-tac-toe.
 * [[Image:Three Men's Morris variant board.svg|100px|left]]
 * }

{|
 * -valign="top"
 * [[Image:Six Men's Morris.svg|100px|left]]

Six Men's Morris
Six Men's Morris gives each player six pieces and is played without the outer square found on the board of Nine Men's Morris. Flying is not allowed. It "was popular in Italy, France and England during the Middle Ages but was obsolete by 1600." This board is also used for Five Men's Morris; Seven Men's Morris uses this board with a cross in the center.
 * }

{|
 * -valign="top"
 * [[Image:Twelve Men's Morris board.svg|100px|left]]

Twelve Men's Morris
Twelve Men's Morris adds four diagonal lines to the board and gives each player twelve pieces. This means the board can be filled in the placement stage; if this happens the game is a draw. This board is also used for Eleven Men's Morris.
 * }

History According to R. C. Bell, the earliest known board for the game includes diagonal lines and was "cut into the roofing slabs of the temple at Kurna in Egypt" c. 1400 BCE. . However, Friedrich Berger writes that some of the diagrams at Qurna include Coptic crosses, making it "doubtful" that the diagrams date to 1400 BCE. Berger concludes, "certainly they cannot be dated."

One of the earliest mentions of the game may be in Ovid's Ars Amatoria. In book III (c. 8 CE), after discussing chess, Ovid wrote:
 * There is another game divided into as many parts as there are months in the year. A table has three pieces on either side; the winner must get all the pieces in a straight line. It is a bad thing for a woman not to know how to play, for love often comes into being during play.

Berger believes the game was "probably well known by the Romans", as there are many boards on Roman buildings, even though dating them is impossible because the buildings "have been easily accessible" since they were built. It is possible that the Romans were introduced to the game via trade routes, but this cannot be proven.

The game peaked in popularity in medieval England. Boards have been found carved into the cloister seats at the English cathedrals at Canterbury, Gloucester, Norwich, Salisbury and Westminster Abbey. These boards used holes, not lines, to represent the nine spaces on the board &mdash; hence the name "nine holes" &mdash; and forming a diagonal row did not win the game. Another board is carved into the base of a pillar in Chester Cathedral in Chester.

In Shakespeare's 16th century work A Midsummer Night's Dream, Titania laments that it is no longer played: "The nine men's morris is filled up with mud" (A Midsummer Night's Dream, Act II, Scene I).

Some authors say the game's origin is uncertain. It has been speculated that its name may be related to Morris dances, and hence to Moorish, but according to Daniel King, "the word 'morris' has nothing to do with the old English dance of the same name. It comes from the Latin word merellus, which means a counter or gaming piece." King also notes that the game was popular among Roman soldiers.

In some European countries, the design of the board was given special significe as a symbol of protection from evil,, and "to the ancient Celts, the Morris Square was sacred: at the center lay the holy Mill or Cauldron, a symbol of regeneration; and emanating out from it, the four cardinal directions, the four elements and the four winds."

Trivia

 * The World Merrills Association ran the World Championships annually at the Ryedale Folk Museum, Hutton le Hole, York, England.

Related games

 * Achi, from Ghana, is played on a Three Men's Morris board with diagonals. Each player has four pieces, which can only move to adjacent spaces.
 * Kensington is a similar game in which two players take turns placing pieces and try to arrange them in certain ways.
 * Luk Tsut K'i ("six man chess") in China and Tapatan in the Philippines are equivalent to Three Men's Morris played on a board with diagonals.
 * Morabaraba, equivalent to Twelve Men's Morris, has been played for thousands of years across Africa.
 * Shax is played on the board of Nine Men's Morris, but with somewhat different rules and with twelve pieces per player instead of nine.
 * Tic-tac-toe uses a three-by-three board, on which players place pieces (or make marks) in turn until one player wins by forming an orthogonal or diagonal line or until the board is full and the game is drawn.