Dice Roller
Such as 2d6, d20 or 3d8+2.
7
- 4, 3
- Individual rolls
- none
- Modifier
- 7.0
- Expected average
- exactly
- Against average
The dice roller accepts standard notation (2d6, d20, 3d8+2) and shows every individual die alongside the total, plus the expected average so you can tell immediately whether a roll was lucky.
How it works
Dice notation is written as count-d-sides plus an optional modifier. 3d8+2 means roll three eight-sided dice and add two. Omitting the count means one, so d20 and 1d20 are the same roll.
expected total = count × (sides + 1) ÷ 2 + modifier
- (sides + 1) ÷ 2
- the mean of a single fair die, 3.5 for a d6, 10.5 for a d20
- Each die is rolled independently from the browser cryptographic generator with rejection sampling, so every face is equally likely.
- Individual results are shown, not just the total, which matters for systems where each die is read separately.
- Between 1 and 100 dice, with 2 to 1000 sides each.
- The expected average is shown next to the total, because "was that good?" is the question a roll actually raises.
A note on how sums behave: one d20 is flat, with every result equally likely. Three d6 is not, totals cluster around 10 and 11, and 3 or 18 each come up once in 216 rolls. Adding dice trades range for predictability, which is why game systems choose between them deliberately.
Examples
Two six-sided dice
Notation
2d6
Result
Two dice shown, total 2 to 12, average 7
Seven is the most common total because it can be made six ways, while 2 and 12 have one each.
A d20 with a modifier
Notation
d20+5
Result
One die, total 6 to 25, average 15.5
10.5 plus 5. The flat distribution is why a single d20 makes outcomes feel swingy.
Rolling a character
Notation
4d6
Result
Four dice shown individually, average 14
The individual values matter here. The usual rule drops the lowest die, which you can only do if you can see them.
Frequently asked questions
Are these dice actually fair?
Fairer than physical ones. Each face comes from the browser cryptographic random source with rejection sampling, so there is no modulo bias. A real die has manufacturing tolerances, and a cheap one with drilled pips is measurably biased toward the six because the one-face has the least material removed.
Why does 3d6 feel different from 1d18?
Because the distributions are completely different. 1d18 is flat, every result equally likely. 3d6 clusters hard around 10 and 11, and the extremes are rare: 3 or 18 each come up once in 216 rolls. Same rough range, very different feel.
What does the modifier do?
It is added to the total after all dice are rolled, not to each die. 3d6+2 rolls three dice and adds two once, giving 5 to 20. Adding two to each die would give 9 to 24, which is a different roll entirely.
Can I roll and drop the lowest die?
Not automatically, but every die is shown individually so you can apply the rule yourself. Roll 4d6 and ignore the smallest. That is the standard method for generating an ability score, and it is why the individual values are displayed rather than just the sum.
I rolled three ones in a row. Is it broken?
On a d6 that is a 1 in 216 chance, which happens regularly over a session. Each roll is independent and the generator has no memory of previous ones. Genuinely random sequences contain more streaks than intuition expects.