Backgammon Rule Variations
The way checkers move is the same almost everywhere, but players have added many extra rules over the years. Some govern the doubling cube in matches, some are used outside matches, and some turn backgammon into a different game with a new starting position. This page explains the ones you are most likely to meet. For the standard rules, see how to play backgammon.
Rules for the doubling cube in matches
In match play, games are worth points, and the first player to reach the agreed total, such as 5 or 7 points, wins the match. The doubling cube lets a player offer to double the value of the current game. The opponent either accepts and takes ownership of the cube, or declines and gives up the game at its current value. Only the owner of the cube may double next.
The Crawford rule
When one player first reaches one point short of winning the match, the next game is played without the cube. This is the Crawford game. Without the rule, the trailing player would double at once in every game, since they have nothing to lose. After the Crawford game, the cube comes back into play for the rest of the match. The Crawford rule is standard in tournaments today.
The Holland rule
An older variation for the games after the Crawford game. Under the Holland rule, the trailing player may double only after both sides have played at least two rolls. The idea was to give the leader a little more breathing room. In practice it complicated cube decisions without adding much, and it has largely fallen out of use.
Rules used outside matches
The Jacoby rule
The Jacoby rule is used in games played outside matches, where each game is scored on its own. It says a gammon or backgammon counts only as a single game unless the cube has been turned during that game. The purpose is to speed things up: a player far ahead cannot simply keep playing on for a gammon without offering the cube. The Jacoby rule does not apply in match play.
Variant games
These variants keep the board and the basic movement but change the start or a few rules. They are a good way to practice specific skills.
| Variant | What changes | What it trains |
|---|---|---|
| Nackgammon | Each side starts with two checkers on the 24-point, two on the 23-point, four on the 13-point, three on the 8-point and four on the 6-point. | Back games, anchors and longer, more complex positions. |
| Hypergammon | Each side has only three checkers, one each on the 24-, 23- and 22-points. | Fast games with sharp hitting and racing decisions. |
| Acey-deucey | All checkers start off the board and enter through the opponent's home board; a roll of 1-2 earns extra moves. | Flexibility and planning from an open board. |
House rules to agree on
Casual games often include small local customs: who moves first, whether a cocked die is rerolled, whether a move can be taken back before the dice are picked up. None of these is wrong between friends, but agree on them before the first roll. In clubs and tournaments, the official rules decide, and the director settles disputes.
Which rules to learn first
If you plan to play matches, learn the Crawford rule right away; it affects every match that gets close. The Holland and Jacoby rules are worth knowing so you are not surprised. The variants are optional, but a few games of nackgammon or hypergammon can sharpen your play in the standard game. Many common rule mix-ups are covered on our know your rules page.