Dice roller
Nothing yet. Results appear here so you can prove what came up.
Dice notation writes a roll as a number of dice, the letter d, and the number of faces: 2d6 means two six-sided dice. A modifier can be added or subtracted, as in 3d8+2, and groups can be combined, as in 4d6-1+d4. Each die is rolled independently and the total is the sum.
How to roll
Rolling several dice is not the same as rolling one bigger one. A d12 gives every value from 1 to 12 equally often; 2d6 gives the same range shifted to 2–12 but with 7 appearing six times as often as 2. That is why board games use multiple dice: they want a hump in the middle rather than a flat line.
Questions
The standard form: an optional count, d, the number of faces, and optional plus or minus terms. d20, 2d6, 3d8+2 and 4d6-1+d4 all work.
Yes. d3, d7 and d100 are all fine, up to two hundred dice at once.
Yes. Every die is drawn separately from the browser’s cryptographic generator, so 4d6 is four honest rolls rather than one number split up.
Because a natural maximum matters in most systems that use dice, and picking it out of a row of numbers is the thing you would otherwise do by eye.