D20 Dice Roller
Roll a twenty-sided die, with advantage or disadvantage and a modifier if you need them.
Quick answer: Press Roll to throw a d20 and get 1 to 20. A natural 20 is a 5% chance, and so is a natural 1. Add a modifier, or roll with advantage or disadvantage.
How to use it
- Choose one, two or three dice and the number of sides.
- Press Roll the dice. The dice fall, bounce and land in a different place and angle every time.
- The numbers are added up under the dice.
What people use it for
- Board games when the dice are lost
- Tabletop role-playing games
- Teaching probability
- Quick random choices
- Games with children
Chances on a d20
| Need at least | Chance on one d20 | With advantage | With disadvantage |
|---|---|---|---|
| 2 | 95% | 99.8% | 90.2% |
| 5 | 80% | 96.0% | 64.0% |
| 8 | 65% | 87.8% | 42.3% |
| 10 | 55% | 79.8% | 30.3% |
| 12 | 45% | 69.8% | 20.2% |
| 15 | 30% | 51.0% | 9.0% |
| 18 | 15% | 27.8% | 2.2% |
| 20 | 5% | 9.8% | 0.3% |
Advantage rolls two d20s and keeps the higher, and disadvantage keeps the lower. Advantage raises the chance of a natural 20 from 5% to 9.75%.
Questions
What are the odds of a natural 20?
1 in 20, which is 5%.
What does advantage mean?
You roll two d20s and take the higher one.
How do I add a modifier?
Type it in the Modifier box, such as 3 or −2. It is added to the final result.
Are the dice fair?
Yes. Each side has the same chance on every roll, and the result is chosen before the dice tumble, using your browser's secure random generator.
Do the dice remember earlier rolls?
No. Every roll is independent, so a streak of the same number does not make it less likely next time.
Is it really random?
Yes. It uses your browser's secure random number generator, the same kind used for security. Each outcome is equally likely, and earlier results do not affect the next one.
Is anything saved or sent?
No. Names and results stay in your browser and are gone when you close the page.
Is it free?
Yes. No sign-up, no limit.