To speed up match play and to increase the intensity of play and the need for strategy, a doubling cube is usually used. A doubling cube is a 6 sided die that instead of the numbers 1, 2, 3, 4, 5, 6 on it, has the numbers 2, 4, 8, 16, 32, 64 on it. If a player believes his position to be superior he may, before rolling the dice on his turn, double, i.e., demand that the game be played for twice the current stakes. The doubling cube is placed with the 2 side face up to show that the game's value has been doubled. His opponent must either accept the challenge or resign the game on the spot. Thereafter the right to redouble (double again) belongs exclusively to the player who last accepted a double. If this occurs, the cube is placed with the face of the next power of 2 showing.

The game rarely is redoubled beyond 4 times the original stake, but there is no theoretical limit on the number of doubles. Even though 64 is the highest number on the doubling cube, the stakes may rise to 128, 256, 512 and so on.

Beavers

A common rule allows beavers - the right for a player to immediately redouble when offered the doubling cube, while retaining the cube instead of giving it back up. (The redouble must be called before the originally doubling player rolls the dice.) In this way, the stakes of the game can rise dramatically.

Beavers are commonly allowed when backgammon is played for money game by game, and usually not allowed in matches.

Raccoons

Another common rule that follows the beaver rule is a raccoon simply means that once a player had said beaver to an initial double and the opponent believes that was a mistake and wants to take advantage of it he can then call a raccoon and double the cube once more.

Similar to beavers, raccoons are commonly allowed when backgammon is played for money game by game, and usually not allowed in matches.

Jacoby Rule

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.

Crawford Rule

The Crawford Rule makes 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; after all, a win in the game by the player in the lead would cause him to win the match regardless of the doubled stakes, while a win by the opponent would benefit twice as much if the stakes are double. Thus there is no advantage towards winning the match to being one point shy of winning, if one's opponent is two points shy!

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.

Not quite as universal as the Jacoby Rule, the Crawford Rule is widely used and generally assumed to be in effect for match play.

Automatic doubles

When automatic doubles are used, 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.

Known variant - all same but 6-6 triples rather than doubles stakes.

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