The 1–6 range
Six faces, one in six each, the most familiar range in the world. Board games, backgammon, Yahtzee and half the arguments in a pub all live inside 1–6.
A physical die is close to fair and not quite there. Casino dice are machined to within a five-thousandth of an inch and carry flush, filled pips for exactly that reason. The moulded cube in a boxed board game has rounded corners, drilled pips and a measurable lean.
One tap gives one die. Raising the count gives you several numbers without repeats, which is not the same as rolling two dice: for a genuine 2d6 total, with doubles possible, the dice roller adds them up properly.
- 1 to 6, both included
- 6 whole numbers
- 16.67%, exactly 1 in 6
- 1 to 10 numbers per draw
- None up to 6 numbers, then unavoidable
- Every draw gets a link that replays it
What a 1–6 draw is for
- Replacing a die that went under the sofa mid-game
- Backgammon, Yahtzee, Monopoly and anything else with pips
- Choosing among six options with equal weight
- Running a quick probability demonstration in a classroom
- Deciding turn order for six players
How the randomness works
Every tap calls crypto.getRandomValues, the browser's cryptographic generator, and asks it for one unsigned 32-bit value. That lands somewhere between 0 and 4,294,967,295, and it then has to be folded down to the 6 numbers in this range.
Folding it down with a plain remainder is where most generators go wrong, an error known as modulo bias. 6 does not divide 4,294,967,296 evenly: 4 values are left over at the top, and wrapping them around would make the first 4 numbers in the range fractionally likelier than the rest. This tool throws away any raw value at or above the last exact multiple of 6 and draws a fresh one instead. That is rejection sampling. It fires about 1 in 1,073,741,824 draws, and it is the difference between 16.67% exactly and 16.67% approximately.
Ask for more than one number and the tool keeps drawing until it holds that many distinct values, then sorts them ascending. Nothing is seeded, nothing is sent anywhere, and each draw is independent of the one before it. The roll history under the tool lives in your browser's local storage, where the clear button empties it. The daily lucky numbers elsewhere on this site work the opposite way on purpose: they use a seeded generator so the same date always returns the same set. How random is random sets the two side by side.
Sixteen point six seven percent per face, exact, which a real die only approximates. The more interesting bias is not in the cube anyway; it is in the shooter. Claims of dice control in craps have never survived a controlled test, and the house edge on a pass line bet stays at 1.41 percent whoever throws. A generator does not shift that either. It only removes the argument about the dice.
- crypto.getRandomValues, the browser's cryptographic generator
- One unsigned 32-bit value, sometimes more
- Rejection sampling onto 6 slots
- 4 of 4,294,967,296 raw values, redrawn
- No. These tools are never seeded
- Your browser. No server ever sees a draw
1–6 — frequently asked
Tap Generate. The range is fixed at 1–6, each face carries a sixth of the probability, and the result is drawn on your device rather than fetched from anywhere.
Not properly. Raising the count draws distinct numbers, so it will never give you a double, and doubles are one throw in six for a real pair. Use the dice roller for 2d6, which rolls each die independently and totals them.
Very. They are cut to tight tolerances, translucent so nobody can hide a weight, pipped with flush inlay so the faces weigh the same, serial-numbered, and retired after a few hours of play. A board game die is moulded, rounded and drilled, and its pips leave one face lighter than the rest.
One in six. Two sixes in a row is one in 36, and six in a row is one in 46,656.