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The backgammon doubling cube: offers, ownership and points
Understand when to double, what take and drop mean, who can redouble and how the Crawford game changes cube availability.
The doubling cube changes a game’s point value. On your turn before rolling, you may offer twice the current value if you have cube access and doubling is allowed. Your opponent either takes and continues at the new value, or drops and concedes the old value. Accepting also gives that opponent control of the next redouble.
You can use the cube entirely for match points; money is not required. This page explains the procedure, not a formula for when every position should be doubled. The USBGF rules and Backgammon Galore cube FAQ describe timing, ownership and optional conventions.
Begin with a centered cube worth 1
The cube starts halfway between the players, so either can offer the first double at an eligible turn. Its value is 1. Many physical cubes have faces 2, 4, 8, 16, 32 and 64; on those, 64 face up in the centered starting position represents 1, not a 64-point game.
The opening move uses the two dice already rolled to decide who starts. Do not insert an ordinary cube offer into that opening roll. On later turns, decide about the cube before you roll. You can have access to the cube even when a checker is on the bar and you cannot enter; being unable to move does not itself prohibit an offer.
Offer, take or drop
Suppose the game is worth 1 and White offers 2:
- Black drops: the game ends and White scores 1. The offered 2 never became the accepted value.
- Black takes: play continues at 2. Put the cube on Black’s side showing 2. White then rolls and plays the turn.
Black now owns the cube. White cannot raise it again merely because White’s position improved. At a later eligible turn, Black may offer 4. If White takes, White owns the cube at 4; if White drops, Black scores 2.
| Accepted value before the offer | Proposed value | Points to the offerer if declined | Owner if accepted |
|---|---|---|---|
| 1, centered | 2 | 1 | The taker |
| 2 | 4 | 2 | The taker |
| 4 | 8 | 4 | The taker |
An accepted cube value multiplies the eventual single, gammon or backgammon result. A gammon on a cube of 4 is worth 8 points. Dropping a double concedes the current value without an extra gammon or backgammon multiplier. See the scoring examples.
Match play: remember the Crawford game
In a standard points match, the first time a player reaches one point short of the target, the next game is played without doubling. That is the Crawford game. If the match continues after it, the cube returns for subsequent games. It is one game without the cube, not a permanent ban whenever a player is one point away. Backgammon Galore’s match rules explain this convention.
For example, in a 7-point match, a player reaches 6–3. The next game has no cube. If the trailer wins one point, the score is 6–4 and doubling returns. A one-point match needs no cube because one game win already decides it.
Keep optional conventions separate
Automatic doubles on tied opening dice, immediate redoubles called beavers, and the Jacoby scoring rule are conventions for some casual or money games, not standard match rules. Do not add them silently. Jacoby limits gammon/backgammon bonuses when no double was accepted; it is not used in match play. For learning, agree to omit these extras.
An app may also offer a single-game mode that disables the cube. Use the rules chosen for that game rather than assuming a missing cube button is an error.
A useful first question before an offer
Ask what could change by your next turn: can a hit, a strong roll or an escape make your advantage much larger? Then consider what a loss would cost at the proposed value. Race length, contact, gammons, cube ownership and match score all matter. A universal “double at this win percentage” shortcut leaves out those details.
Learn how to read a beginner position before memorizing advanced cube thresholds. For your first few games, practicing the correct offer/take/drop sequence is a worthwhile goal on its own.