Dice Roller

How to use Dice Roller

1. Choose how many dice and how many sides.
2. Roll, and read the individual results and the total.
3. Roll again as often as you need — each roll is independent.
4. Each die is rolled independently from the browser’s cryptographic random source.
5. Non-standard side counts work too, for games using a d3 or a d30.
6. Works offline once the page has loaded.

A fair die, which a real one is not quite

The results come from the browser’s cryptographic random source, so every face is equally likely and no roll is influenced by the last. Physical dice are not quite fair: the pips are drilled out, so the 6 face is marginally lighter than the 1, which biases a cheap die very slightly toward 6. Casino dice compensate by filling the pips with material of the same density, which is why they are transparent and sharp-edged. A virtual die has none of this to correct for.

Rolling several dice does not give a flat distribution

One d6 is uniform — every number 1 to 6 equally likely. Two d6 are not: seven comes up on six of the thirty-six combinations and twelve on only one, so seven is six times more likely. That triangular distribution is the whole design of backgammon, craps and Monopoly. Three or more dice cluster even harder around the middle, which is why 3d6 for a roleplaying statistic produces mostly average characters and the occasional memorable extreme.

Dice notation

The standard shorthand is NdS: 2d6 is two six-sided dice, 1d20 is one twenty-sided. A modifier follows, so 1d8+3 means roll a d8 and add three. Tabletop games use a standard set — d4, d6, d8, d10, d12 and d20, the five Platonic solids plus the d10 — and d100 is usually two d10 read as tens and units. Advantage, in modern roleplaying rules, means rolling two d20 and taking the higher, which shifts the average from 10.5 to about 13.8.