The doubling cube is a six-sided die with 2, 4, 8, 16, 32, 64 on its faces. It’s not for rolling — it’s for raising the stakes.

If you’ve ignored it until now, that’s fine. Most casual games skip it. But once you understand it, the game becomes deeper.

What it actually does

At the start of a match, the cube sits in the middle of the bar with “64” facing up — meaning the game is currently worth 1 point (the 64 is just the cube’s “off” position).

At any point during your turn, before you roll, you can offer to double the stakes. You’re saying: “I think I’m winning. Want to play for double?”

Your opponent has two choices:

Take — the game now counts for 2 points instead of 1. They get the cube on their side.
Drop — they concede the game right now, and you win 1 point.

If they take, the cube is now on their side. They can later offer to redouble to 4. Then 8. Then 16. The cube can only be turned by whoever owns it.

Why this is interesting

It introduces judgment into a game that would otherwise be pure mechanics. Now you have to evaluate: am I winning by enough that they should drop? Or am I winning by exactly enough that they’ll take and I’ll win double?

The math has been worked out in detail (Edward O. Thorp, Bill Robertie, computer rollouts), and there’s a concept called the “take point” at around 75% chance to win. Rough rule of thumb:

You’re winning by a lot (~80%+) → double, expect them to drop
You’re winning solidly (60–75%) → don’t double yet (you’re throwing away free rolls)
You’re winning marginally (52–60%) → double aggressively if you have the cube
You’re losing slightly → if they double, take (you still have decent equity)
You’re losing badly (<25%) → if they double, drop

These are starting heuristics. Rollouts get more nuanced.

When you’ll see it most

In money games and matches — first-to-7-points or whatever the match length is. In casual single games, the cube doesn’t add much. It shines over a series.

The “Crawford rule”

In match play, when one player is one point away from winning the match (the “Crawford game”), the cube is off for that game only. After that game (regardless of who won), the cube comes back on. This is to prevent the trailing player from doubling instantly every game out of desperation.

Beaver, raccoon — skip these

You’ll see fancier doubling rules in some online games. Beaver = redouble immediately when accepted. Raccoon = beaver the beaver. They’re optional. Most platforms turn them off by default. Don’t worry about them yet.

When to start using the cube

After you’ve played ~20 games and the basic moves feel automatic. Before that, you have enough to think about.

Try the cube in a match →