In backgammon, sometimes you are only a few checkers ahead, but one correct doubling decision can multiply the value of the game. Conversely, an early Double or incorrect Take can ruin the result of an otherwise well-played game. This is where backgammon moves beyond “just dice and checker moves” and brings decision-making, probability, and risk management into the picture.
Doubling in backgammon, or the Doubling Cube, allows a player to double the current value of the game. The opponent does not have to accept the offer; they must choose between Take and Pass. Should I accept and play for the higher value, or give up the game right here? This simple decision is one of the most important foundations of Cube Play in modern backgammon.
What Exactly Is Doubling in Backgammon?
The Doubling Cube is a six-sided cube with the numbers 2, 4, 8, 16, 32, and 64. It shows the current value of the game and also indicates which player has the right to Redouble. At the beginning of the game, the Cube is placed in the center of the board, usually with 64 facing up. This number does not mean the game is worth 64 at the start; on standard cubes, 64 represents the initial value of 1.
The usual progression of the game value is:
1 → 2 → 4 → 8 → 16 → 32 → 64
The USBGF also explains that when the Cube is centered, both players have the right to make the first Double. After a Double is accepted, that right goes to the player who takes the Double.
When Are You Allowed to Double?
The basic rule is simple: a player may Double only at the beginning of their turn and before rolling the dice. For example, if it is your turn, you have not rolled yet, and you believe the position is worth more, you offer the Cube. Once you have rolled the dice, you no longer have an opportunity to Double during that turn.
There is an interesting point here as well. Suppose you have a checker on the Bar and have no legal entry available. You still have the right to Double before rolling the dice. Having no legal move does not remove your right to make a Cube Action at the beginning of your turn. The USBGF explains the same sequence in its basic doubling rules.
When You Double, What Choices Does Your Opponent Have?
Under the standard rules, a player who receives a Double has two main choices:
Take means accepting the Double.
Pass or Drop means rejecting the offer and conceding the game at its current value.
It may look simple, but these two options form the core of many professional backgammon decisions.
What Is a Take?
Take means that the opponent agrees to continue the game at twice its previous value.
Suppose the game is at 1:
Player A doubles.
Player B takes.
The game value changes from:
1 → 2
But the Cube number is not the only thing that changes. From this point, Player B owns the Cube, and only B has the right to Redouble in the future. So a Take is not simply “accepting a higher value”; it also gives you ownership of the Cube. That ownership itself has strategic value.
What Is Pass or Drop?
Sometimes the position is so weak that continuing the game at double the value is not logical. In that case, the player Passes.
The important point is:
By Passing, you lose the value before the Double, not the new Cube value.
For example, the Cube is on 2.
The opponent Redoubles:
2 → 4
If you Pass, you lose 2 points, not 4.
Why? Because you did not accept the offer to play for 4 points and instead conceded the game at the previous stake. The USBGF rules and GNU Backgammon both describe the same method for Double and Redouble.
What Is Cube Ownership?
Cube ownership is one of the aspects that beginners often underestimate. Suppose Ali doubles and Reza takes. The Cube moves to 2 and Reza becomes the owner. A few turns later, the game changes and Reza now has a strong advantage. Because he owns the Cube, he has the right to Redouble:
2 → 4
Now Ali must choose Take or Pass. If he takes, the Cube transfers to Ali. So under the standard Cube procedure, the right to Redouble moves between the two players.
What Is a Redouble?
Any Double that occurs after the initial Double is called a Redouble.
For example:
1 → 2
2 → 4
4 → 8
8 → 16
Under the standard rules, Cube ownership changes after a Take. Therefore, the player who has just doubled does not immediately have the right to Redouble again.
There is, however, an important exception: Beaver in some Money Games. Beaver allows an immediate Redouble while retaining Cube ownership, but it is not part of standard Match Play rules. The USBGF also defines Beaver specifically for Money Game.
How Many Times Can You Double?
Under the basic rules, there is no specific limit on the number of Redoubles.
The sequence can continue to high values:
1 → 2 → 4 → 8 → 16 → 32 → 64
GNU Backgammon and the USBGF both state that there is no specific limit on the number of Redoubles. Of course, in an ordinary game, it is very uncommon for the Cube to reach extremely high values.
How Is the Final Game Value Calculated After a Double?
The final value does not depend only on the Cube number. The type of win also enters the calculation.
There are three main outcomes:
Type of Win
Multiplier
Single win
1
Gammon
2
Backgammon
3
Suppose the Cube is on 4.
Single win:
4 × 1 = 4
Gammon:
4 × 2 = 8
Backgammon:
4 × 3 = 12
So the Cube also multiplies the value of gammons and backgammons. For example, a backgammon with the Cube on 8 is worth 24 units. GNU Backgammon and the USBGF explain the same system for calculating the game result.
A Complete Example of Double, Take, and Redouble
Suppose Ali and Reza are playing and the initial game value is 1.
Ali has a good position and offers a Double before rolling:
1 → 2
Reza has two choices.
If he Passes, he loses 1 unit and the game ends.
If he Takes, the game continues at 2 and Reza becomes the Cube owner.
Reza Takes.
A few moves later, the situation changes. Reza now has the better position and Redoubles:
2 → 4
Now Ali has to decide.
If he Passes, he loses 2 units.
If he Takes, the game continues for 4 units and Cube ownership goes to Ali. This example shows a fundamental point: the Cube is not only about who is ahead; the timing of the decision also matters.
Should We Only Double When We Are Far Ahead?
No. This is one of the common mistakes beginners make. Does doubling mean “I am ahead of you”? Not exactly. The real question is: Is now the right time to increase the value of the game? You may have a good position, but it may still be too early to Double.
On the other hand, you may have a lower chance of winning than your opponent, yet Take can still be the correct decision. In professional Cube Play, factors such as winning chances, gammon chances, Race or Contact position, Cube ownership, Volatility, and in Match Play the match score all affect the decision. This is where the subject moves beyond a simple rule and into real backgammon analysis.
What Is the 25 Percent Rule for Take?
In introductory Cube training, there is a well-known rule of thumb: if you expect to win at least around 25 percent of the games from that position, in a very simple model the value of Take and Pass becomes roughly equal. The USBGF uses this example for basic explanation: if you win one out of every four doubled games and lose the other three, the basic result is equivalent to making four consecutive Passes. But do not treat this number as a universal Take rule.
Twenty-five percent is an educational starting point, not a formula that works for every position. Why? Because in a real game the Cube is still alive, Cube ownership has value, and you may be able to Redouble later. Gammons and backgammons also change the calculations. In Match Play, the match score makes the situation even more complex. That is why the actual Take Point varies depending on the position and type of game.
What Is Take Point?
Take Point is the threshold below which continuing the game is not valuable enough and Pass becomes preferable. In the simplest model without gammons and without future Cube value, we see the approximate 25 percent figure. But with a live Cube, by taking you are not only buying your current chance of winning; you are also receiving the potential right to Redouble in the future.
This additional value is sometimes called Recube Vig. In practice, this is what makes real Take analysis more complicated than a fixed percentage. GNU Backgammon also analyzes Cube decisions by comparing the Equity of different options rather than relying only on a fixed Take Point.
What Is the Doubling Window?
Not every advantage is suitable for a Double. Early in an advantage, it may still be too soon to Double. As the position improves, you enter the Doubling Window, the range in which a Double has value and the opponent can still Take. If the advantage becomes much larger, you may pass the Cash Point and the opponent will no longer have a Take.
In simple terms:
Too early: No Double
Appropriate range: Double / Take
Larger advantage: Double / Pass
Of course, gammon-heavy positions introduce another interesting situation: Too Good to Double.
What Does Too Good to Double Mean?
Suppose you are so far ahead that your opponent will immediately Pass if you Double. Normally, you might say, “Great, Double and end the game.” But sometimes the chance of winning a Gammon is so high that continuing the game at the current Cube value is worth more than Double/Pass.
For example, with the Cube on 1:
If you Double and your opponent Passes, you receive 1 unit. But if you continue playing and have a high chance of winning a Gammon, your expected value from continuing may be greater than 1. In such a position, you may be Too Good to Double. The USBGF also uses this term for a position in which the gammon chances are so high that taking an immediate Pass is not necessarily the best choice.
How Is Doubling Different in Money Game and Match Play?
This difference should not be underestimated. In Money Game, each game has its own independent value. For example, each Point may be worth a specific amount of money. In Match Play, the goal is to reach a final score, such as a 7-point match. This difference changes the logic of the Cube.
In Money Game, you mainly think about the Equity of the current game. In Match Play, you must consider how winning or losing a certain number of points changes your chances of winning the entire match. That is why a particular position might be Double/Take in Money Game but require a different decision at a specific Match Score.
Optional Money Game Rules
Some Money Games also include several contractual rules:
Jacoby Rule
Beaver
Raccoon
Automatic Double
These rules should not automatically be applied to official Match Play. The USBGF explicitly separates Automatic Double, Beaver, and the Jacoby Rule from Match Play. GNU Backgammon also makes the same distinction in its Match Play rules.
Crawford: The Most Important Doubling Restriction in a Match
Suppose you are playing a 5-point match and the score is 4–2. The first player is only one point away from winning the entire match.
The next game is the Crawford Game. In this one game, the Doubling Cube is removed from play and neither player has the right to Double.
If the trailing player wins the Crawford Game, subsequent games continue with the Cube again. The official USBGF rules effective from January 2025 state this explicitly: the first game after one player reaches a score one point short of winning the match is played without the Cube.
What Is a Dead Cube?
Do not confuse Dead Cube with Crawford. Suppose one player, with the current Cube value, would win the entire Match by winning this game. For that player, increasing the Cube further has no benefit because winning at the current value is already enough to finish the Match.
The USBGF calls this situation a Dead Cube and states in its official rules that the Cube is Dead for a player who would win the match by winning at the current Cube level, making Cube Action at that level invalid. For example, in a 5-point match with a score of 1–1, if the Cube reaches 4, the winner of the game will in any case exceed the required score. Increasing it to 8 provides no additional match benefit.
Are Beaver and Raccoon Used in Official Tournaments?
In standard Match Play, no. Beaver is a Money Game rule. With a Beaver, the player who receives a Double accepts it and immediately increases the Cube again, but unlike a normal Redouble, keeps Cube ownership.
For example:
1 → Double → 2
Take + Beaver → 4
The USBGF specifically identifies Beaver in its Glossary as a Money Game rule. Raccoon comes one step after Beaver and is also a Money Game agreement rather than part of the standard structure of official tournaments.
What Is an Automatic Double?
In some Money Games, players agree before starting that if both players roll the same number on the opening roll, the game value will automatically be doubled. For example, both players roll 5. The Cube moves from 1 to 2 but remains centered.
As a result, both players still have the right to make the first optional Double. The USBGF says players generally agree in advance on the number of Automatic Doubles, and many games limit it to once per game.
Touching the Cube Is Also Governed by Match Rules
In a friendly game, touching the Cube may not seem particularly important; in an official tournament, the situation is different. Under USBGF rules, if a player touches the Cube or makes a move or statement that reasonably indicates an intention to Double, they may be required to make the Double.
However, simply reaching toward the Cube does not necessarily constitute a Double. If you only intend to move the Cube, it is better to clarify your intention before touching it. These details may seem minor, but at a tournament table they help prevent disputes.
Cube Play Is Not Just a Rule; It Is a Skill of Its Own
A beginner usually sees the Cube like this:
Double → opponent chooses Take or Pass.
An experienced player has several more questions in mind:
What percentage chance do I have of winning?
How likely is a Gammon?
Does my opponent still have a Take?
Could I lose my Market with one good roll?
If I do not Double now, will I get another opportunity?
How valuable is Cube ownership to my opponent after a Take?
How does the Match Score affect the decision?
These questions are what make Cube Play an independent part of backgammon.
Sometimes you can quickly find the best checker play, but the Cube decision is several times harder.
What Does Lose Your Market Mean?
Suppose the position is currently Double/Take. If you do not Double and roll an excellent number, your position may improve so much that your opponent will no longer Take on the next turn. Now if you Double, they will only Pass and you will win the current value.
In effect, you have lost the opportunity to play for twice the Stake. This situation is called Lose Your Market. The USBGF uses this term for a situation in which a player misses the opportunity to Double while the opponent still has a Take.
Where Should You Start Learning About Doubling?
If you are new to Cube Play, it is better to progress step by step.
First, learn these five concepts without ambiguity:
Double → Take → Pass → Cube Ownership → Redouble
Then move on to calculating game value:
1 → 2 → 4 → 8 → 16
Next, add Gammon and Backgammon to the calculations. Once that part is clear, learn Take Point and Cash Point. The next stage is Doubling Window, Market Loser, and Too Good to Double. After that, study the difference between Money Game and Match Play more seriously, and finally move on to Match Equity and Gammon Value.
You do not need to memorize all of these concepts in one night. Cube Play is one of those areas that gradually becomes clear by seeing real positions.
A Simple Exercise to Improve Your Doubling
The next time you play, before every roll, take a few seconds to ask yourself: “If the Cube were mine right now, would I Double?” When your opponent doubles, estimate your approximate winning percentage before choosing Take or Pass. Then review the game with GNU Backgammon or a reputable analysis engine. This exercise quickly shows where you are being overly conservative and where you are turning the Cube too early. After a few dozen positions, patterns will gradually start to emerge.
Final Thoughts
The basic doubling rule is not complicated. At the beginning of your turn and before rolling, you offer a Double. Your opponent either Takes and continues the game at twice the value, or Passes and concedes the previous game value. After a Take, Cube ownership goes to the player who accepted the Double, and that player has the right to make the next Redouble.
But that is only the first layer. Once Take Point, Doubling Window, Gammon Value, Market Loser, and Match Score enter the game, the Cube is no longer just an object beside the board; it becomes part of the game's strategy. The professional question is no longer simply: “Am I ahead or behind?” A better question is: “Is now the best time to Double, or should I wait one more turn?” That small question can sometimes change the entire value of the game.