Doubling Cube

The doubling cube is often used in backgammon games. The role of the die marked with the numbers 2, 4, 8, 16, 32 and 64 is to bring a new level of intensity to the backgammon game (especially when playing backgammon for money) and raises new strategy questions. 

A player who wishes to double the stake, has to wait for its turn and offer the opponent to double right before he rolls the dice. The opponent may refuse or accept the double. If refuses, he forfeits the game and gives up the initial stake. If he agrees – the cube is turned so the number 2 would face upward. 

After the first double offer has been accepted, the stake upon which the game is played is doubled. The last player who had accepted the offer, becomes the owner of the cube and only he may offer to redouble (again, only on his turn and not after the dice have been rolled). 

The use of the doubling cube in the backgammon game continues in the same manner. The number of redoubles is not limited, yet it is not common to double more than 4 times.

Raccoon – an optional additional to the beaver which allows the player who had just accepted a beaver (two consecutive doubles) to immediately offer a re-double. 

Jacoby Rule – often used in money games, the Jacoby Rule allows gammons and backgammons to be counted as a single game, as if a double has been offered and accepted. 

Crawford Rule/Crawford Game – used in match play, according to the Crawford Rule, if a game has ended with a score of one point, the next game will be played without the doubling cube. The Crawford Game is the game following the one point game played without the doubling cube. 

Woolsey's Rule – not exactly an alternative backgammon rule, Woolsey's Rule has to be read as a guiding principle to all backgammon players. According to Woolsey's Rule, whenever there's uncertainty on whether to accept or pass a double, accept is always the correct decision.