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Roll any dice, instantly
On the defaults (2 six-sided dice, no modifier): totals run from 2 to 12, the expected total is 7, and rolling 9 or better happens about 27.8% of the time. Roll below — or change the dice.
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Dice Roller
Rolling dice by hand is slow, and mental math on 8d6 is worse. Pick your dice, set a modifier, choose a roll mode — every roll is instant, the odds are shown, and the math is explained below.
Why 7 is the magic number on 2d6
Two six-sided dice have 36 equally likely outcomes (6 × 6). Only one pair makes 2 (1+1) and only one makes 12 (6+6), but six pairs make 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1). That is why 7 is the most common total in craps, backgammon, and countless board games — and why game designers build around it.
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Total rolled | sum of all dice + modifier | The number you actually use: 7 on average with the defaults. |
| Each die | 1 + floor(random × sides) | Every face equally likely — a fair die has no memory. |
| Minimum possible | dice × 1 + modifier | 2 on the defaults: the floor of the range. |
| Maximum possible | dice × sides + modifier | 12 on the defaults: the ceiling. |
| Expected value | dice × (sides+1) ÷ 2 + modifier | 7 — the long-run average over thousands of rolls. |
Worked example: 2d6, no modifier
Roll 2 six-sided dice. The 36 outcomes: total 2 appears once, 3 twice, 4 three times, 5 four times, 6 five times, 7 six times, 8 five times, 9 four times, 10 three times, 11 twice, 12 once. Expected value = (1+2+3+4+5+6) ÷ 6 × 2 = 7. The chance of rolling 9 or better = (4+3+2+1) ÷ 36 = 27.8%. Add a +3 modifier and every total shifts up by exactly 3 — the odds shape does not change.
Advantage, in plain numbers
Advantage (roll twice, keep the higher) on a d20 raises the average roll from 10.5 to about 13.8 — roughly a +3 to +4 bonus. The chance of a natural 20 nearly doubles, from 5% to 9.75% (1 − (19÷20)2). Disadvantage mirrors it: average drops to about 7.2, and the chance of a natural 1 nearly doubles too.
Who uses this
- Tabletop RPG players: D&D, Pathfinder, and indie systems — attack rolls, damage, and saving throws without hunting for physical dice.
- Board gamers: settling disputes and replacing lost dice mid-game.
- Teachers: demonstrating probability live — roll 2d6 fifty times and watch the 7s pile up.
- Game designers & developers: sanity-checking dice mechanics and expected values before playtesting.
Accuracy & limitations
This roller uses your browser’s built-in pseudorandom generator, which produces a uniform distribution — every face is equally likely, and rolls are independent. That is exactly what games need. It is not cryptographically secure randomness: never use it for gambling, lotteries, passwords, or anything where money or security is at stake (use the password generator for secrets, which uses crypto-grade randomness). Figures shown are exact combinatorics, not estimates.
Pair it with the random number generator for raffles and draws, or the list shuffler for random turn order.
Cite this calculatorBright Side Kit. “Dice Roller.” brightoolbox.com, 2026.
Bright Side Kit. "Dice Roller." https://brightoolbox.com/dice-roller/ Accessed October 22, 2026.Frequently asked questions
Is this dice roller really random?
Yes — as random as a fair physical die. Each roll is an independent uniform draw, so every face has exactly the same chance (1 in 6 on a d6, 1 in 20 on a d20). What it is not is cryptographically secure: do not use it for gambling, real-money games, or security decisions.
What are the odds of rolling a natural 20 on a d20?
5% — exactly 1 in 20, every single roll. Dice have no memory: the odds are 5% whether you just rolled three 20s in a row or have never rolled one.
How does advantage change the odds?
With advantage you roll twice and keep the higher, so the chance of a natural 20 becomes 1 − (19÷20)2 = 9.75% — nearly double. The average d20 roll climbs from 10.5 to about 13.8. Disadvantage is the mirror image: the average falls to about 7.2.
What does “2d6+3” mean?
Roll two six-sided dice, add them together, then add 3 to the total. The modifier applies once to the total, not to each die — so 2d6+3 ranges from 5 to 15, averaging 10.
What is the average roll of 2d6?
7. Each d6 averages 3.5, and two of them average 7. More generally, the average of NdS is N × (S+1)÷2 — so 3d8 averages 13.5.
Can I roll more than 20 dice?
The roller caps at 20 dice per roll to keep results readable. Need more? Roll again and add the totals — the math stays exact.
Does the modifier apply to each die or to the total?
To the total, once. A +2 on 3d6 shifts the whole 3–18 range to 5–20. This matches standard tabletop notation.
Can I share a specific roll with someone?
The “copy link” button encodes your dice setup (count, type, modifier, mode) so a friend opens the same configuration — the random result itself is re-rolled fresh each time, which is the fair way to do it.