Beavers

A beaver refers to the ability of players to redouble the doubling cube and keep it after the opposing player offers it up. One player will offer the doubling cube and the opposing player is permitted to redouble immediately, if done before the first player rolls for their turn. After the redouble, second player is allowed to keep the doubling cube for future use. Often, this can lead to astronomical rises in the stakes for a game. This rule does not apply to tournament play, but can be option for online Money play if both players are willing to accept the rule.

The Jacoby Rule

As proposed by Backgammon great Oswald Jacoby, the Jacoby rule requires that gammons and backgammons only be worth two and three points if the doubling cube has been used at some point throughout the game. The purpose of the rule is to speed up the game. Forcing a player with a potential gammon or backgammon to play the doubling cube, the opposing player can then drop the cube and lose the one point instead of playing out the remainder of a long game in which their opponent gains two or three points.

The result of this rule is that some games can result in massive scores, especially if a player is within striking range of winning a match. The opposing player can also come back much quicker with the required use of the doubling cube. Often though, it results in shorter matches.

The Crawford Rule

The Crawford rule in Backgammon is a common rule, and is used in tournaments and match play. When a player is only one point away from winning a match, the doubling cube is removed from play for that game. The Crawford game is only played once however, so any subsequent games in which a player is still one point from winning the match, the doubling cube is replace in the game. The result of this rule is that a player cannot use the doubling cube to immediately win the game. It gives the leading player the chance to win the game with a normal win.

Automatic Doubles

Automatic doubles adds a degree of chance to the stakes of any game by investing importance in the original roll used to decide which player goes first. If a re-roll is necessary for the first roll, the stakes are automatically doubled. If there is another re-roll, the stakes are doubled again. They continue doubling until a player wins the initial roll.

The stakes can then be raised again later with the use of the doubling cube by either player. Money games often employ this rule as it adds a degree of chance and excitement to the game. However, both players must first agree to the rule addition.