Dice & Coin
Type any dice notation or tap a die. Rolls use your browser’s cryptographic random generator, with a running history, the possible range and average, and a coin flip below.
Dice notation
NdS rolls N dice with S sides: 3d6, d20 (one die), d% (percentile, 1–100). Add or subtract dice and numbers freely: 1d8+2d6+3, d20-1.
Keep and drop: 4d6kh3 keeps the highest three (k3 means the same), 2d20kl1 keeps the lowest one (disadvantage), and dl1 / dh1 drop the lowest or highest. Dropped dice are shown faded, and in brackets in the breakdown. Exploding dice (3d6!) roll again whenever they hit their maximum. 4dF rolls Fate/Fudge dice worth −1, 0 or +1.
Every die is rolled with crypto.getRandomValues and rejection sampling, so each face is exactly equally likely. The min, max and average shown are for the expression, not the roll; averages for keep/drop rolls are computed exactly for small pools and estimated for large ones.
Questions
What does 4d6kh3 mean?
Roll four six-sided dice and keep the highest three — the classic way to roll ability scores in Dungeons & Dragons. The result ranges from 3 to 18 and averages about 12.24.
How do I roll with advantage or disadvantage?
Advantage is 2d20kh1 (roll two d20s, keep the higher); disadvantage is 2d20kl1 (keep the lower). Add your modifier at the end, e.g. 2d20kh1+5.
Is this dice roller truly random?
It uses your browser’s cryptographically secure random number generator with rejection sampling to remove modulo bias. That is as fair as software randomness gets, and fairer than most physical dice.
Is a coin flip 50/50 here?
Yes, each flip is an independent crypto-random choice. Streaks of five or six in a row are normal in a hundred flips; the streak counters show just how often they happen.