Backgammon Rules

Also shown is a pair of dice in the center of the left half of the board and the doubling cube, a six sided cube with the numbers 2, 4, 8, 16, 32 , 64 on the sides. Each number represents the value of the current stakes, with 64 standing for both 1 and 64, since it is unlikely that the players will confuse these two values at any time!

The red colored rectangles on the left side of the board are actually half-cylinders which hold the stones before they are placed on the board and after they are borne off at the end of the game. The four quarters of the board are called the inner and outer boards on the left and right respectively and the opponent’s inner and outer board, with the opponent’s inner board also being the player’s home board. All the brown areas of the board are slightly raised from the table surfaces, so the stones sit in the depressed areas, colored blue in the illustration. The center raised area is called the bar and it has a special function in the game.

The general intent of the game is for each player to try to move all his fifteen pieces around the table, from their starting positions completely off the board. In this case the player with the black stones is moving them counter-clockwise, while the person with the white stones is moving clockwise. At each toss of the two dice, the players must move two stones the exact number of points of the two dice, if possible. An exception is when doubles are thrown, two twos, two threes, etc. In that case four moves must be taken, again if possible. Another exception is when a player is bearing off, removing his pieces from the game, which is explained below. A particular move is impossible if the opponent has two or more stones already placed on the target point, called an anchor.

For example, in the starting position shown in the illustration, with white having thrown a five and a six, he can not move either of the two pieces on the one-point to the six-point, where for this player the points are numbered from one to twenty four starting in the upper left corner, and proceeding clockwise around the board, the opposite for his opponent. If the target point contained only one of the opponent’s pieces, the move could have been made and the opponent’s piece…which has been hit…is then placed on the bar, at the center of the board. In that case, the very first move that must be taken, if possible, by the opponent when it is his turn, must move the piece from the bar into his inner table, with the placement corresponding to either one of his thrown dice. Again, if a point contains two or more of the opponent’s pieces, the stone can not be moved from the bar to that point. When all of one’s pieces have finally been moved into the opponent’s inner table, you can begin to bear them off the board. That is, any stone whose distance from the off table containers exactly matches the one of the dice can be taken from the board and placed in the stone holder. Once there it is “safe” from further hits. If no stone is exactly that distance, then if the stone furthest back from the stone container is closer than one of the dice values, it can be removed as well. If not, then, as usual, the stones must be moved the exact distance indicated by the dice. The first player who has removed all fifteen of his pieces wins that game. If his opponent has not removed a single piece by that time, the result is called a “gammon” and the stakes are doubled, if the players have agreed before hand to that variation of the rules. It is as though the winning player has won two games instead of just one. If the losing player has any pieces still in his inner table by the time the game ends…called a "backgammon"…the stakes may be tripled, again according to prior agreement on the rules. In some countries, both a gammon and backgammon both count for only two games.

The addition of the doubling cube enlarges the scope of the game as a gambling game enormously. At the beginning of the game, and until one or the other has doubled the stakes and his opponent has accepted, either player may double, or request that the stakes may be doubled, if he does so before he shakes the dice. If his opponent accepts that double, the stakes are doubled and the doubling cube moves over to the opponent’s side of the board. He now has possession of the cube and is the only person who may double again. It is also said that he owns the cube. If he declines to accept the double, the game is over and he loses whatever is the current stake. Thus, it is possible, for doubling to take place, back and forth, each time doubling the previous stakes, until very high values have been achieved. Note that if the game has been doubled and re-doubled three times, the stakes are then eight. If the loser is gammoned, they are sixteen. If he is backgammoned, the stakes are twenty four!

You can see why this innovation is so interesting. Of course, the players can decide to play the game without using the doubling cube, which is safer, if less exciting. Tournaments generally have somewhat different rules. In that case, matches are played rather than just a single game. A winner of a match is determined by whoever wins a particular number of games first, which is determined before the match. In this case, doubled stakes or a gammon count for two won games toward the match. There is an additional wrinkle, called the Crawford Rule after a famous U.S. gambler named Johnnie Crawford, who originated it. It is a very special rule that says that if one of the players is within a single game of winning the contest, then for the very next game…and only that game…the doubling cube is not used. This is to prevent the lesser player from raising the stakes capriciously in order to double his chances of recovering from his deficit, since the player in the lead has no incentive whatsoever to double the stakes himself. Of course, if the losing player survives the Crawford Game, which is what it is called, he can do as he pleases thereafter.

Tournaments can be single elimination, where someone who has lost a match is eliminated, or double elimination, where one must lose twice to be knocked out. Usually, tournaments are structured so that, at the beginning, some power of two players are involved. The person who survives all contests, or, in the case of double elimination, all but one, is usually the winner. In tournaments involving monetary stakes, some of the players at in the quarter- or semi-finals may also be rewarded. There are many variations on all of these rules, but these are the most common of them.