The Backgammon Doubling Cube Explained Simply
In many games there is a third die next to the two normal ones, marked 2, 4, 8, 16, 32 and 64. It adds tension and tactics – and is easier to understand than it looks.
What is the doubling cube?
The doubling cube shows what the current game is worth. It was introduced in American gaming clubs in the 1920s and changed the game for good. At the start it sits in the middle and the game counts once.
How doubling works
- Before rolling, you may offer your opponent a double.
- Your opponent decides: take – the game is now worth double and they get the cube – or drop – they lose the current value immediately.
- Only the player who owns the cube may double next. So the cube moves back and forth.
Combined with gammons (double) and backgammons (triple), a single game can quickly be worth many points.
When to double, when to take
- Double when you are clearly ahead, but not so far ahead that your opponent would drop at once. A good moment is often just before your advantage becomes large.
- Take if you would still win about one game in four from the position (around 25%). Over time you lose less than by dropping.
- In a pure race the pip count helps: when the leader is about 8–9% ahead a double is reasonable; from about 12% the opponent should drop.
Crawford, Jacoby & co.
| Rule | Meaning |
|---|---|
| Crawford rule | In matches to a set number of points: when one player needs just one point to win, no doubling is allowed in the next game. |
| Jacoby rule | In money games: gammons and backgammons only count if the cube has been turned. This prevents endless games. |
| Beaver | A player who takes may immediately redouble while keeping the cube (only if agreed). |
For starters: Feel free to play your first games without the doubling cube. On our site every game counts the same for the leaderboard.
More terms like gammon, anchor or blot are in our backgammon glossary.
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