Dice / dice-roller
Dice roller
From d4 to d100, with total and histogram.
- Sourcecrypto.getRandomValues()
- Entropy—
- draws12
A fair die is a uniform generator over n values. This tool uses the same primitive as the number generator — a 32-bit draw with out-of-range rejection — applied per face, die by die. There is no generator per die: there is one source, read n times.
The histogram below accumulates session results. With a d20 and five hundred rolls each face should appear about twenty-five times: visible deviations are statistical noise, not bias, as long as they stay within the expected variance.
How it works
- 01Pick the die type and how many to roll: the total is summed with the modifier.
- 02Each face is drawn independently: two dice may show the same value, exactly like at the table.
- 03The histogram grows with every roll and shows whether the distribution stays flat.
Frequently asked
Dice roller
Are rolls independent?
Yes. Each face is a separate draw from the same cryptographic source. There is no memory of previous rolls: a 20 stays 1/20 even after ten 20s in a row.
Can I use it for tabletop RPGs?
That is the use case: d4, d6, d8, d10, d12, d20 and d100 with modifier and count. The total is shown separately from individual rolls, so you see both.
Why is the histogram not perfectly flat?
Because it is finite. Standard deviation over n rolls is about sqrt(n·p·(1-p)): with 100 d6 rolls expect ±4 per face. Only thousands of rolls make differences negligible.