Under the roll you can see the exact probability of every possible total, and the chance of rolling at least the number you need.
Dice notation
| You type | Meaning |
|---|---|
d20 | One 20-sided die |
3d6+2 | Three six-sided dice plus 2 |
1d8+1d6-1 | Mixed dice and a modifier |
4d6dl1 or 4d6kh3 | Roll four d6, drop the lowest (keep the highest three) |
2d20kh1 / 2d20kl1 | Advantage / disadvantage |
d% or d100 | Percentile die, 1 to 100 |
How the rolls and odds work
DiceKit draws each die from your browser's cryptographic random number generator (crypto.getRandomValues), using rejection sampling so no face is favoured. Nothing is sent anywhere. The odds are exact: plain dice are combined one at a time (a convolution of their distributions), and keep or drop rules are calculated by counting every possible combination. Only very large keep or drop pools are estimated by simulation, and the result says so.
Handy averages
| Dice | Average | Range |
|---|---|---|
| d6 | 3.5 | 1–6 |
| 2d6 | 7 | 2–12 |
| 3d6 | 10.5 | 3–18 |
| 4d6 drop lowest | 12.24 | 3–18 |
| d20 | 10.5 | 1–20 |
| d20 with advantage | 13.83 | 1–20 |
| d20 with disadvantage | 7.18 | 1–20 |
| 8d6 | 28 | 8–48 |
Frequently asked questions
Is this dice roller random?
Yes. It uses your browser’s cryptographic random number generator with rejection sampling, so every face is equally likely.
What does 2d6+3 mean?
Roll two six-sided dice, add them and add 3.
What does d% mean?
A percentile die, 1 to 100, the same as d100.
Is DiceKit free?
Yes, with no sign-up or ads.
Is my roll history saved?
Yes, in this browser only, and you can clear it at any time.