Backgammon Dice Roller
Two dice, rolled with cryptographic randomness — the fairest throw a browser can make. Roll for an over-the-board game when the real dice have gone missing, settle who goes first, or just watch the 36 combinations do their statistical work.
How This Roller Works
Most "random" web dice quietly use Math.random(), a general-purpose generator never designed for fairness guarantees. This one asks the browser's cryptographic generator (crypto.getRandomValues) for random bytes — the same source used to create encryption keys — and applies rejection sampling: because 256 is not divisible by 6, the values 252–255 would make some faces slightly more likely, so those bytes are simply thrown away and redrawn. What remains maps to the six faces with mathematically equal probability. No time-based seed, no modulo bias, no memory of the previous roll.
All 36 Combinations
Two dice produce 36 equally likely ordered combinations, and everything strategic in backgammon flows from that grid. The totals are not equally likely, and the difference is enormous:
| Total | Ways to roll it | Chance |
|---|---|---|
| 2 or 12 | 1 each (1-1 / 6-6) | 2.8% each |
| 3 or 11 | 2 each | 5.6% each |
| 4 or 10 | 3 each | 8.3% each |
| 5 or 9 | 4 each | 11.1% each |
| 6 or 8 | 5 each | 13.9% each |
| 7 | 6 | 16.7% |
Seven is the king of totals — six of the 36 combinations produce it — which is why checkers sitting 7 pips apart are in the crossfire of more rolls than any other indirect distance. The full hitting table, distance by distance, lives in our probability basics guide.
Doubles: One Roll in Six
Exactly 6 of the 36 combinations are doubles, and in backgammon a double plays four times, not two: 4-4 means four moves of four. That single rule makes doubles the most powerful throws in the game — 6-6 moves 24 pips at once, three times the average roll of about 8.17. The roller flags every double it throws and keeps a running tally, so you can watch your observed doubles rate drift toward the theoretical 16.7% as the sample grows. Short sessions will swing wildly; that is randomness working, not failing.
When You Need More Than Dice
If you rolled your way into an actual game, the setup visualizer will get the board arranged correctly, and the pip counter will tell you who is winning once the middle game blurs. And when you would rather have an opponent, a board and provably fair server-side dice all in one place, you can play backgammon free in your browser — no install, matched with a real player in seconds.