D&D Dice Roller
Roll D&D 5e dice with advantage, disadvantage, critical hits, keep/drop pools and 4d6 ability scores.
Total
Press Roll dice (or Enter in the notation box) to roll.
Roll history
Ability scores — 4d6, drop the lowest
Total 0 · Sum of modifiers 0
How it works
A dice roller built for Dungeons & Dragons 5th edition. Type any standard notation —
1d20+5, 2d6+3, 8d6 for a fireball, or keep/drop pools
like 4d6kh3 (keep highest 3), 2d20kl1, 4d6dl1 (drop
lowest 1). Choose Advantage or Disadvantage and a single
1d20 is rolled twice, keeping the higher or lower die exactly as the 5e rules
say; the discarded die is still shown, struck through. Tick Critical hit and
every dice pool is doubled while flat modifiers stay untouched — the 5e crit rule.
The line under the quick rolls previews the roll before you make it: the possible range and
the exact average. Averages for keep/drop pools are computed by full enumeration of every
outcome, not simulated — so 4d6kh3 averages 12.24 (exactly 15869 ⁄ 1296), an
advantage 1d20 averages 13.82 (exactly 13.825) and disadvantage 7.18. The
ability score generator rolls 4d6 and drops the lowest six times and shows each score's
modifier, calculated as ⌊(score − 10) ⁄ 2⌋.
Rolls use your browser's cryptographic random number generator
(crypto.getRandomValues) with rejection sampling, so every face is equally likely
— no modulo bias. Add ?seed=42 to the URL for reproducible rolls (handy for
play-by-post disputes or testing). Everything runs locally in your browser: no server, no
account, no ads and no tracking, and the page keeps working offline.
Frequently asked questions
How do I roll with advantage or disadvantage?
Pick Advantage or Disadvantage under the notation box and roll a single d20. The roller turns 1d20 into 2d20kh1 (keep highest) for advantage or 2d20kl1 (keep lowest) for disadvantage, exactly as D&D 5th edition says, and still shows the discarded die struck through so you can see both results. An advantage d20 averages 13.825 instead of 10.5; disadvantage averages 7.175.
What does 4d6kh3 mean?
It means roll four six-sided dice and keep the highest three — the standard D&D ability score roll, also written 4d6dl1 (drop lowest 1). The roller accepts kh, kl, dh and dl suffixes on any pool, and the preview line shows the exact average of 12.24 (15869/1296), computed by enumerating every possible outcome rather than simulating rolls.
Are the dice rolls actually random?
Yes. Rolls come from your browser's cryptographic random number generator, crypto.getRandomValues, with rejection sampling so every face is equally likely and there is no modulo bias. If you want reproducible rolls instead — for play-by-post or for settling a dispute — add ?seed=42 to the URL and the same sequence comes back every time. Nothing is ever sent to a server.