Backgammon rules in short: Backgammon is a board game of skill for two players. The board consists of twenty-four triangles (points, spaces) and fifteen checkers (pieces or men) for each backgammon player. Each player roll two dice and tries move all his checkers to home board and after that bear off them from the backgammon board. During moving his checkers, player can hit enemy checkers that makes more harder for enemy to move all his checkers to home board.
Object of the backgammon: The object of the game is for each player to bring all his checkers into his home board, and then to bear them off the board. The first player to clear all his checkers off the board is the winner.
Hitting and Entering: In backgammon a point occupied by a single checker of either color is called a blot. If an opposing checker lands on a blot, the blot is hit and placed on the bar. Anytime a player has one or more checkers on the bar, his first obligation is to enter that checker(s) into the opposing home board. A checker is entered by moving it to an open point corresponding to one of the numbers on the rolled dice. For example, if a player rolls 4 and 6, he may enter a checker onto either the opponent` four point or six point, as long as the prospective point is not occupied by two or more of his opponents` checkers. If neither of the points is open, the player loses his turn. If a player is able to enter some but not all of his checkers, he must enter as many as he can and then forfeit the remainder of his turn. After the last of a players` checkers have been entered, any unused numbers on the dice must be played.
Bearing Off: This is the final stage of backgammon. Once a player has moved all of his fifteen checkers into his home board, he can begin bearing off. A player bears off a checker by rolling a number that corresponds to the point on which the checker resides, and then removing that stone from the board. If there is no checker on the point indicated by the roll, the player must make a legal move using a checker on a higher-numbered point. If there are no checker on the higher-numbered points, the backgammon player can remove a stone from the next highest point. A player is under no obligation to bear off if he can make an otherwise legal move. A player must have all of his active checkers in his home board to bear off. If a checker is hit during the bear-off process, the player must bring that checker back to his home board before continuing to bear off.
The Doubling Cube: Backgammon is played for an agreed wager (or number of points in the tournament play). During the course of the game, a player who feels he has a sufficient advantage may propose doubling his stakes. He may do so, only at the start of his turn, and before he has rolled the dice. A player who is offered a double may refuse, in which case he concedes the game and pays the original wager. Otherwise, he must accept the double and play on for the new higher stakes. A player who accepts a double becomes the owner of the cube and only he may make the next double. Subsequent doubles in the same game are called redoubles. If a player refuses a redouble, he must pay the wager that was at stake prior to the redouble. Otherwise, he becomes the new owner of the cube and the game continues at twice the previous stakes. Redoubles can increase the original wager by up to 64 times.
Gammons and Backgammons: At the end of the game, if the losing player has borne off at least one checker, he loses only the value showing on the doubling cube (the original wager or one point if there have been no doubles). However, if the loser has not borne off any of his checkers, he is gammoned and loses twice the value of the doubling cube. Moreover, if the loser has not borne off any of his checkers and still has a checker on the bar or in the winners` home board, he is backgammoned and loses three times the value of the doubling cube.
Optional backgammon rules:
The Jacoby Rule makes gammons and backgammons count for their respective double and triple points only if there has been at least one use of the doubling cube in the game. This encourages a player with a large lead in a game to double, and thus likely end the game, rather than see the game out to its conclusion in hopes of a gammon or backgammon. The Jacoby Rule is widely used in money play, but is not used in match play.
When Automatic Doubles are used in backgammon, any re-rolls that players must make at the very start of a game (when each player rolls one die) have the side-effect of causing a double. Thus, a 3-3 roll, followed by a re-roll of 5-5, followed by a re-roll of 1-4 that begins the game in earnest, will cause the game to be played from the start with 4-times normal stakes. The doubling cube stays in the middle, with both players having access to it. The Jacoby Rule is still in effect. Automatic Doubles are common in money games (upon agreement). They are never used in match play.
When a player is doubled, he may immediately redouble (beaver) while retaining possession of the doubling cube. The original doubler has the option of accepting or refusing as with a normal double.
The Crawford Rule makes backgammon match play much more fair for the player in the lead. If a player is one point away from winning a match, his opponent has no reason not to double. To remedy this situation, the Crawford Rule requires that when a player becomes one single point short of winning the match, neither player may use the doubling cube for a single game, called the Crawford Game. As soon as the Crawford Game is over, any further games use the doubling cube normally.