D&D dice roller
Roll any dice: type notation like 2d6+3 or 4d6kh3, tap a die for a quick roll, and switch on advantage or disadvantage for d20s. Your last 20 rolls stay in the history.
Dice notation cheat sheet
Dice notation is how D&D writes a roll: the number of dice, a “d”, then the number of sides. 3d8 means roll three eight-sided dice and add them up. A number after a plus or minus sign is a flat modifier. The roller understands all of these:
| Notation | What it means | Range | Average |
|---|---|---|---|
1d20 | One twenty-sided die | 1–20 | 10.5 |
1d20+5 | A d20 plus a modifier: an attack roll or check | 6–25 | 15.5 |
2d6+3 | Two six-sided dice plus 3: a greatsword hit | 5–15 | 10 |
1d8+1d6+2 | Different dice added together | 4–16 | 10 |
8d6 | Eight six-sided dice: a Fireball | 8–48 | 28 |
4d6kh3 | Roll four, keep the highest three (same as 4d6dl1) | 3–18 | 12.24 |
2d20kh1 | Advantage: roll two d20s, keep the higher | 1–20 | 13.83 |
2d20kl1 | Disadvantage: keep the lower | 1–20 | 7.18 |
d% | Percentile: 1 to 100 (the same as d100) | 1–100 | 50.5 |
- kh and kl keep the highest or lowest dice (
kalone means kh); dl and dh drop the lowest or highest (dalone after a roll means dl). - Terms can be subtracted as well as added:
1d20-1,2d6-1d4. - Up to 100 dice per term and up to 1,000 sides per die.
Advantage and disadvantage
With advantage you roll two d20s and use the higher; with disadvantage, the lower. Pick Advantage or Disadvantage above and every single d20 in your roll is rolled twice, so 1d20+5 with advantage becomes 2d20kh1+5. Other dice aren’t affected.
Advantage raises the average d20 from 10.5 to 13.83, and disadvantage lowers it to 7.18. Near the middle of the die that’s worth about +5 on a single roll; at the ends it’s worth much less.
| Need to roll | Normal | Advantage | Disadvantage |
|---|---|---|---|
| 2 or higher | 95% | 99.75% | 90.25% |
| 5 or higher | 80% | 96% | 64% |
| 8 or higher | 65% | 87.75% | 42.25% |
| 10 or higher | 55% | 79.75% | 30.25% |
| 11 or higher | 50% | 75% | 25% |
| 12 or higher | 45% | 69.75% | 20.25% |
| 15 or higher | 30% | 51% | 9% |
| 18 or higher | 15% | 27.75% | 2.25% |
| 20 or higher | 5% | 9.75% | 0.25% |
Advantage and disadvantage don’t stack: two sources of advantage still mean two dice, and if you have both advantage and disadvantage they cancel out and you roll one d20, however many sources of each you have.
Average of each die
A die’s average is half of one more than its number of sides, so the average of several dice is easy to work out: 8d6 averages 8 × 3.5 = 28. That’s what the fixed damage in a monster’s stat block is based on.
| d4 | d6 | d8 | d10 | d12 | d20 | d100 |
|---|---|---|---|---|---|---|
| 2.5 | 3.5 | 4.5 | 5.5 | 6.5 | 10.5 | 50.5 |
Is it random?
Every roll uses your browser’s cryptographic random number generator (crypto.getRandomValues), the same source browsers use for encryption keys, and throws away the rare values that would favor low numbers, so each face of each die is exactly as likely as the others. Nothing is sent anywhere: the rolls happen on your device.
Playing a character? The character builder’s sheet has a dice roller wired to your attacks, spells and checks, so you don’t type any notation at all. For spell damage, see the spell list.
Common questions
What does 4d6kh3 mean?
Roll four six-sided dice and keep the highest three. It’s the usual way to roll an ability score, and it means the same as 4d6dl1 (drop the lowest one). The ability score roller rolls all six at once.
How do advantage and disadvantage work in 5e?
Roll two d20s and take the higher (advantage) or the lower (disadvantage). They only apply to d20 rolls: attack rolls, ability checks and saving throws, never to damage.
What is a d% roll?
A percentile roll: a number from 1 to 100, made at the table with two ten-sided dice (one for the tens, one for the ones). It’s the same as d100 here.
Does advantage stack?
No. Several sources of advantage still give you one extra die, and any advantage plus any disadvantage cancel out completely.
Is this dice roller fair?
Yes. It uses the browser’s cryptographic random numbers and rejects out-of-range values so no face is favored.
Can I roll damage for a critical hit?
Double the dice, not the modifier: a 1d8+3 hit becomes 2d8+3 on a critical hit. Type the doubled roll into the box.
Related pages
- D&D 5e spells damage dice for every spell
- Monster stat blocks
- Ability score roller
- How to make a character