About the Dice Roller
This online dice roller is ready whenever you can't find real dice โ for board games, drinking games or deciding who goes first. Choose how many dice and how many sides, press the button and the dice tumble to show each value and the total. Results come from your browser's cryptographic random number generator (crypto.getRandomValues), so every face has exactly the same chance.
Your last 30 rolls are saved on this device, so you can close the page and still see your history and average later.
How to use
- Choose the number of dice (1โ6) and the die type (D4โD20). A standard cube die is a D6.
- Press Roll dice or tap the green dice tray. On a computer you can also press the space bar.
- Read each die and the total below. If every die shows the same number, you'll get a special message.
- In Roll history, compare your average total with the expected value.
Probabilities for the total of two dice
Two dice give 36 equally likely combinations, but the totals are not equally likely. The middle value, 7, comes up most often.
| Total | Ways | Chance |
|---|---|---|
| 2 or 12 | 1 | 2.78% |
| 3 or 11 | 2 | 5.56% |
| 4 or 10 | 3 | 8.33% |
| 5 or 9 | 4 | 11.11% |
| 6 or 8 | 5 | 13.89% |
| 7 | 6 | 16.67% |
The chance of rolling a double (two of the same) is 6/36 = 16.67%.
Polyhedral dice (D4โD20) and expected values
Board games and tabletop RPGs such as Dungeons & Dragons use dice with different numbers of sides. The notation 2D6 means "two six-sided dice". The expected value (average) of one N-sided die is (N + 1) รท 2.
| Die | Shape | Expected (1 die) |
|---|---|---|
| D4 | Tetrahedron | 2.5 |
| D6 | Cube | 3.5 |
| D8 | Octahedron | 4.5 |
| D10 | Pentagonal trapezohedron | 5.5 |
| D12 | Dodecahedron | 6.5 |
| D20 | Icosahedron | 10.5 |
For several dice, multiply by the number of dice. For example, 3D6 has an expected total of 10.5.
FAQ
Are the rolls really random?
Yes. Each value comes from crypto.getRandomValues in your browser; the tumbling animation is just for show. Every face is equally likely.
I got the same number several times in a row. Is that a bug?
No. Dice have no memory, so repeats are more common than people expect. The chance of the same number three times in a row on one D6 is about 2.8%.
Why are 6 and 9 underlined on the D10?
Like on real polyhedral dice, the underline tells 6 and 9 apart when the die is upside down.
Can I skip the animation?
Turn on "reduce motion" in your device settings and results appear instantly without the rolling animation.