Backgammon (Anglo-Saxon bac, back, game, game), game which probably appeared in England as early as the 10th century. It is played on a board which opens up to form two equal compartments, each containing two 'tables', consisting of six long triangular 'points' coloured alternately black and white, and numbered.
Each player calls one side of the board his 'inner table' and the other his 'outer table". One player has 15 white pieces and the other 15 black pieces, similar to draughtsmen. At the start, white has two men on black's one-point, five on black's twelve-point, five on his own six-point and three on his own eight-point; while black places five men on his own six-point, three on his eight-point, five on white's twelve and two on white's one. Each player throws two dice and moves any man the number of points corresponding to the number thrown. He may move one man for all the pips on the dice, or move two men, one in accordance with each die; but he cannot move one man the full distance if it is impossible to move in two stages according to the pips of each die. Each player moves his men from his opponent's inner table over to his opponent's outer table, into his own outer table, then to his own inner table. A man can only be played to a point which is either vacant or occupied by one or more of his own men or only one of his adversary's. A player getting two men on a single point is said to 'make' that point. A single man on a point is known as a 'blot'; and if the opponent plays to it he 'hits a blot', 'takes up' the man hit and places it on the central bar where it stays until it can be played again on to the opponent's inner table on a later throw. While it is on the bar its owner cannot play any of his other men, nor may he move it from the bar until he throws a number corresponding to a vacant point or a blot on his opponent's inner table. If a player throws two equal numbers he scores a doublet and plays double his throw.
When a player has moved all his men into his inner table he is allowed to 'bear them off (remove them from the board). Each throw entitles him to move a man or men within his own table or to lift men from the points corresponding to the number thrown. If a player who has begun bearing off throws a number with no man on it he must move if this is possible. But if he throws a number which he cannot move and from which he cannot bear off, he bears off from the highest point—that is, if he throws a six and the six-point is empty he may bear off from five. The first player to bear off all his men wins the game. If he bears off all his men before his opponent has borne off any, his win is a 'gammon' and the loser pays double the stakes. If the winner bears off all his men while his adversary still has a piece on the bar or in the winner's inner table, the game is a 'backgammon' and the loser pays three times his stake. A match is often played three up—three ordinary wins or 'hits', a hit and a gammon, or one backgammon for the rubber.
Russian backgammon is similar to the English game, varying in very few rules.
The game was given a boost in the USA earlier this century with the introduction of the 'Doubling Cube'. This has the numbers 2,4, 8, 16, 32 and 64 on the six sides. At the start of the game the doubling cube is placed 'neutral', and stakes are deemed to be single agreed units. To start the game each player casts one die only and the higher thrower moves as if he had cast both dice. If a double appears on the combined throw each must cast again and the doubling cube is faced to '2', still in the mutual position. Thereafter either player may, before throwing, offer his opponent 'doubled stakes' by facing the cube towards him, turned to denote the new stakes. The opponent may accept (in which case the higher stakes apply) or reject in which case the game is won by the offerer at the stake then ruling. Thereafter only the player to whom the cube is faced may offer a further double.
A recent variation (said to have started in Cyprus) provides for no men to be placed on the 'points' at the start of the game, but all 15 have to enter the board in the opponent's inner table as though they were on the bar. Since a great block becomes built in the outer tables the average game takes about three times as long as ordinary backgammon, which averages 12 minutes.
In all forms of backgammon it is possible for the 'weaker' player to receive a handicap (as at chess). It can be agreed that at any time during the game he can reject, or demand that his opponent reject, a cast on one (or more) occasions during the game. As in croquet, this is known as a 'bisque'.
The early 1970s saw huge interest in the game develop, witnessed in the mushrooming of clubs and tournaments, and although the oldest of the board and dice games, it is nowadays easily the most popular, together with 'duplicate' backgammon played on the lines of duplicate contract bridge.