Writing a roll
A dice randomizer for any roll in the rulebook, one die or multiple dice of different kinds at once:
- 2d6+3: roll two d6 and add 3.
- 8d6: eight d6, a Fireball.
- 4d6kh3: roll four d6 and keep the highest three. 4d6dl1 says the same thing.
- 2d20kh1 and 2d20kl1: advantage and disadvantage.
- 1d8+1d6+2: a longsword with a d6 of extra damage, plus a modifier.
- d100 or d%: a percentile roll.
Why notation
Dice notation is the shorthand every rulebook uses, and it removes arguments: "2d6+3" means one thing. The Dice Notation Guide explains every part of it, from the basic XdY to modifiers, percentile rolls and dropping the lowest die.
What common rolls come to
Exact averages, counted over every way the dice can land:
| Roll | What it is | Average |
|---|---|---|
| 2d6 | Board-game turn | 7 |
| 2d6+3 | Greatsword, +3 Strength | 10 |
| 3d6 | Old-school ability score | 10.5 |
| 4d6kh3 | Ability score, drop lowest | 12.24 |
| 2d20kh1 | Advantage | 13.83 |
| 2d20kl1 | Disadvantage | 7.18 |
| 8d6 | Fireball | 28 |
| 1d8+1d6+2 | Longsword plus 1d6 | 10 |
Dropping the lowest die is worth more than it looks: 4d6kh3 rolls 15 or higher 23.1% of the time, against 9.3% for plain 3d6. The dice calculator draws the full curve for any of these, and the stat roller rolls a whole character in one go.
Rolls you use every session
Typing the same roll every turn gets old. The main roller saves whole lists of rolls, one tap each, in your browser. For one kind of die at a time, the d6, d20 and d100 rollers are a tap away.
Questions
How do I roll multiple dice at once?
Type them as one roll. 5d6 rolls five d6 and adds them; 1d20+1d4+3 rolls a d20 and a d4 and adds 3. Each term takes up to 100 dice, and every die is shown alongside the total.
What does 4d6kh3 mean?
Roll four d6 and keep the highest three. kh keeps the highest, kl keeps the lowest, dl drops the lowest and dh drops the highest, so 4d6dl1 is the same roll. It averages 12.24, the usual way to roll ability scores.
How do I roll with advantage?
Type 2d20kh1: two d20, keep the higher. Disadvantage is 2d20kl1. Advantage turns an even 50% chance of 11 or higher into 75%. The advantage roller has a button for it.
What dice can it roll?
Any die from 2 sides to 1000: d2, d3, d7, d30 and d1000 all work, along with the usual d4 to d20. Type d100 or d% for a percentile roll.
Is this random dice generator fair?
Yes. Each die comes from your browser's cryptographic random number generator, with no bias towards any face, so every face of a d20 is exactly 1 in 20.
How do I add or subtract a modifier?
Put it on the end: 1d20+5, 2d6-1. Spaces are fine, so 1d20 + 1d4 - 1 reads too. The Dice Notation Guide covers every part of the notation.