One die, many dice
Strictly, one is a die and two or more are dice, so a single virtual die is still "roll a dice" to most people, and nobody at the table will correct you mid-fight. The roller above does both: choose a die, set how many, and the total comes out with every die shown so you can check the sum.
Which die do I need?
| If you are rolling | Use |
|---|---|
| An attack, a saving throw or a skill check | d20 |
| A coin flip, or a yes or no | d2 |
| One of three, or 1d3 damage | d3 |
| Damage from a dagger, or a Bless bonus | d4 |
| Damage from a shortsword, or a Fireball | d6 (Fireball is eight of them) |
| Damage from a longsword or rapier | d8 |
| Damage from a heavy crossbow or Fire Bolt | d10 |
| Damage from a greataxe | d12 |
| A wild magic surge or a treasure table | d100 |
| A table with a thousand entries | d1000 |
Are virtual dice fair?
Each face has the same chance, the same as on a well-made real one. The number comes from your browser's cryptographic random generator, and the roller throws away the few values that would tilt the result towards low numbers, so a d6 lands on each face one time in six. For a whole character's worth of dice in one go, the main roller keeps lists you can save.
Odds for board games
Virtual dice stand in for lost ones on game night too. Set the die to d6 and the count to match your game. The odds, worked out exactly:
| Roll | Chance |
|---|---|
| Doubles on two dice | 16.7% (1 in 6) |
| A total of 7 on two dice | 16.7% (1 in 6) |
| Double six on two dice | 2.8% (1 in 36) |
| At least one 6 on four dice | 51.8% |
| All five dice the same, in one throw | 0.08% (1 in 1,296) |
Seven is the likeliest total on two dice because six pairs make it. The two dice and five dice rollers are set up for those games, and the dice calculator works out any other roll.
Questions
What are virtual dice?
Dice rolled by a computer instead of by hand. A virtual die picks a face at random with the same chance for each, then shows you the result. This one rolls a d4, d6, d8, d10, d12, d20 or d100, up to 20 at a time.
Are virtual dice really random?
Yes. Every roll here comes from your browser's cryptographic random number generator, the same kind used for passwords, and values that would favour low faces are thrown away and drawn again. Each face of a d6 comes up exactly 1 time in 6.
Is it "roll a die" or "roll a dice"?
One is a die and two or more are dice, so "roll a die" is the textbook form. "Roll a dice" is how most people say it, and either one gets you the same roller.
Can I roll several virtual dice at once?
Yes. Set how many, from 1 to 20, and roll. You see every die and the total. For a mix such as 2d6 + 1d8, use the dice notation roller or the main roller.
How do I add a modifier?
Set the modifier, from −20 to +20, before you roll. It is added once to the total, not to each die, which is how D&D and most games count it: 1d20 + 5 is one d20 plus 5.
Can I use virtual dice for board games?
Yes. Choose the d6 and set two dice for most board games or five for dice-poker games. The result is as fair as a good real die, and you never lose one under the sofa.