How to roll dice online
- Use the + and − buttons to choose how many of each die to roll. You can mix types, for example two d6 and one d20, up to 20 of each.
- Add a modifier if your game calls for one, such as +3 for a skill bonus.
- Press Roll, or press Space or Enter on your keyboard.
- Read the big total. The line under it lists every die, so you can see each value when your game needs it.
The roll button always shows what you are about to roll in standard dice notation, such as 2d6 + 1d20 + 3. Your choices are remembered on this device, and the history keeps your last 30 rolls.
The dice
| Die | Range | Average roll | Common uses |
|---|---|---|---|
| d4 | 1 to 4 | 2.5 | Small damage, dagger hits |
| d6 | 1 to 6 | 3.5 | Board games, classic dice games |
| d8 | 1 to 8 | 4.5 | Weapon damage, hit points |
| d10 | 1 to 10 | 5.5 | Percent rolls in pairs, some RPG systems |
| d12 | 1 to 12 | 6.5 | Heavy weapon damage |
| d20 | 1 to 20 | 10.5 | Attack rolls and skill checks |
| d100 | 1 to 100 | 50.5 | Percent chances, random tables |
The average of any single die is the number of sides plus one, divided by two. For several dice, add their averages: 3d6 averages 10.5 and ranges from 3 to 18.
Probability basics
One die is flat: every face is equally likely. A d20 lands on 20 exactly 5% of the time, the same as it lands on 1 or 11.
Add two or more dice and the totals start to bunch up in the middle. With two d6 there are 36 equally likely combinations. Six of them add up to 7, so 7 comes up 1 time in 6. Only one combination makes 2 and only one makes 12, so each of those is a 1 in 36 shot. That is why games built on 2d6 treat 7 as the common result and 2 or 12 as rare.
Dice have no memory. After three 1s in a row, the next roll of a d6 still has a 1 in 6 chance of each face. Feeling that a high roll is "due" is a common trap called the gambler’s fallacy.
Rolling with advantage
Some games ask you to roll two d20 and keep the higher one. Set two d20 and read both values in the result line. Keeping the higher of two raises the average from 10.5 to about 13.8, and the chance of at least one 20 goes from 5% to 9.75%.
When to use a virtual dice roller
It is handy when the real dice are lost, when you play over a video call, or when you need many dice at once and do not want to add them up by hand. Teachers use it for probability lessons: roll 2d6 a few dozen times and the bunching around 7 becomes easy to see.
For a single number in any range, use the Random Number Generator. For a quick heads or tails, flip a coin.
Questions
Are the virtual dice fair?
Yes. Each die is rolled with your browser’s cryptographic random number generator, and every face has exactly the same chance. A virtual d20 shows each number 5% of the time.
What do d4, d6 and d20 mean?
The number after the d is how many sides the die has. A d6 is a normal six-sided die, a d20 has 20 sides. "2d6" means roll two six-sided dice and add them.
How do I add a modifier?
Type a number in the Modifier box, for example 3 or -2. It is added to the total of every roll, the way a character bonus works in many tabletop role-playing games.
Is there a keyboard shortcut?
Press Space or Enter to roll while the dice are on screen. Enter also rolls while you are typing in the Modifier box.