Dice Roller
Roll any number of dice with any sides.
How to use
- Pick the dice type, from D4 up to D100.
- Set how many of that die to roll and add an optional modifier like plus 2.
- Tap Roll to throw the dice and see each individual result plus the total.
- Use the dice notation field for advanced rolls like 2d6 plus 1d4 plus 3.
- Open History to review your last 20 rolls.
Frequently asked questions
What dice notation does this support?
Standard tabletop notation: NdS where N is the number of dice and S is the number of sides, plus optional modifiers like +3 or -1. You can combine multiple groups, for example 2d6+1d4+3.
Are the rolls truly random?
Yes. Each face is chosen with cryptographic randomness via crypto.getRandomValues, so the dice are fair and the results are unpredictable.
Can I roll percentile dice?
Yes. A D100 gives a result from 1 to 100. For 1d10 and 1d10 percentile pairs, roll 2d10 and read the digits separately.
Does the tool work for online D&D sessions?
It is designed exactly for that. Roll openly with a friend in a video call, or share the result text in chat.
Dice notation, decoded
The standard notation NdS means roll N dice with S sides: 3d6 rolls three six-siders and sums them, d20 rolls one twenty-sider, 2d6+3 adds a fixed modifier. The polyhedral family (d4, d6, d8, d10, d12, d20, plus paired d10s as percentile d100) comes from tabletop gaming, where each die shape produces a deliberately different probability profile. A digital roller evaluates the whole expression at once and never rolls off the table.
Why 3d6 and 1d20 feel completely different
One die gives a flat distribution: on a d20 every value from 1 to 20 has an equal 5% chance, so extremes are common... which is why d20 systems feel swingy. Summed dice form a bell curve: 3d6 makes 10 and 11 far likelier (12.5% each) than 3 or 18 (0.46% each), because mid totals have many combinations and extremes only one. Game designers choose between them deliberately: flat dice for drama, summed dice for predictable competence. The same logic explains why 2d6 in backgammon makes 7 the most common roll (six ways out of thirty-six).
Practical rolling notes
- Advantage/disadvantage mechanics (roll twice, keep best/worst) shift the d20 average from 10.5 to about 13.8 or 7.2... a bigger swing than a +3 bonus.
- For fair group decisions, dice beat "pick a number": humans choosing "randomly" famously over-pick 7 and 17.
- Digital rolls suit remote game sessions where everyone must see the same result, and statistics homework where you need 500 samples in seconds rather than an evening.
Quick probability answers players actually ask
- Chance of at least one 6 in four d6 rolls: about 52%... the bet that built probability theory (de Mere's problem).
- Rolling doubles on 2d6: 1 in 6, regardless of which double.
- Beating a 15 on a d20: 25% flat; with advantage it jumps to about 44%.
- 3d6 lands between 8 and 13 nearly two-thirds of the time... mid-range results dominate summed dice.
- The "hot streak" of three high rolls in a row needs no explanation beyond chance; across a four-hour session, streaks are guaranteed somewhere.
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