The objective of backgammon is to be the first to successfully move their checkers off the board.
The game is played on a board consisting of 24 narrow triangles called points. The Backgammon board is divided into four quadrants, each with six points. The quadrants are labeled as follows: 1-6 for the first quadrant (starting from the top right for one player and bottom right for the other), 7-12 for the second quadrant, 13-18 for the third quadrant, and 19-24 for the fourth quadrant.
Each player begins with 15 checkers of their own color. They are arranged as follows: two on the 24-point, five on the 13-point, three on the 8-point, and five on the 6-point. The players' home board is the quadrant containing points 1-6, and their outer board is the quadrant containing points 19-24.
The players take turns to roll two dice and move their checkers accordingly. The numbers rolled on the dice represent the number of points a player can move their checkers. The numbers on the dice can be used separately or together to make a single move.
A checker can be moved to any open point on the board, or to a point occupied by the player's own checkers. However, a point occupied by two or more of the opponent's checkers cannot be landed on. A player must use both dice numbers if possible, but if only one move is legal, they must play that number.
If a player lands on a point occupied by a single opponent checker, the opponent's checker is hit and placed on the bar, a strip in the middle of the board. To reenter the game, the opponent must roll a number that corresponds to an open point in the opponent's home board. If they cannot enter any checkers, they lose their turn.
Once a player has moved all of their checkers to their home board, they can start bearing off. The player must roll a number that matches an open point within their home board to bear off a checker. If a higher number is rolled, the player can bear off a checker from a higher point. If a player cannot make a legal move, they lose their turn.
Backgammon often includes a doubling cube, which starts at 1 and can be doubled by the player in control of it. The cube is used to increase the stakes of the game. The opponent has the option to accept or refuse the double, which determines the final value of the game.
If a player bears off all their checkers before the opponent has borne off any, it is called a "gammon," and the winning player earns double the value of the doubling cube. If the losing player has not borne off any checkers and still has checkers on the bar or in the opponent's home board, it is called a "backgammon," and the winning player earns triple the value of the doubling cube.
The game is won when a player successfully bears off all their checkers before the opponent, or when the opponent cannot bear off any checkers, loses all their checkers, or concedes the game.
These are the basic rules of backgammon. There are also various optional rules and variations that players may choose to use, such as the Jacoby Rule or the Crawford Rule, to add complexity