Random Dice Roller
Roll d4 through d100 dice online, with a modifier - free, no signup.
What this tool does
Pick a die type (d4, d6, d8, d10, d12, d20 or d100), how many dice to roll, and an optional +/- modifier, then press Roll. Every individual die result is shown alongside the sum and the final total with your modifier applied - useful for tabletop games, classroom probability demos, or any time you need a fair virtual die.
Rolls any number of d4, d6, d8, d10, d12, d20 or d100 dice at once, using the browser's cryptographically secure random source.
Applies an optional positive or negative modifier to the total, the standard tabletop convention (e.g. 2d6+3).
Shows every individual die result alongside the dice sum and the final modified total.
Re-rolls automatically the instant you change die type, dice count or modifier - each of those is a fresh roll of every die, not just a relabelling of the previous result.
Converts each die's random draw with a modulo-bias-free integer method, so even an odd size like d100 stays evenly distributed across its full range.
How to use it
- Choose a die type.
- Set the number of dice and any modifier.
- Press Roll to see each die and the total.
Why use this generator
Tabletop games and probability exercises need dice, which you may not have to hand. A roller handles every common die and modifier.
Why we built it
We built the dice roller to cover the whole polyhedral set from d4 to d100 with a modifier, showing every individual die. Calculate odds with the probability calculator and flip coins with the coin flip.
Who this tool is for
- Tabletop gamers
- Teachers and students learning probability
- Board-game players without dice
When to use it
- Playing tabletop or role-playing games.
- Teaching probability.
- Settling a tie.
- Rolling many dice at once.
Why every individual die is shown
Tabletop games usually need the individual rolls, not just the sum.
Many tabletop rules care about the individual dice, not only their sum - checking for doubles, applying a rule to the highest or lowest die, or confirming a critical hit on a natural maximum roll. Showing only a combined total would hide that information, so every individual die result is displayed alongside the sum and the final total with any modifier applied.
How the dice avoid a subtle bug called modulo bias
Turning a random draw into a die result can quietly skew the odds if the math is done the naive way.
A common shortcut for turning a random integer into a dice roll is to take a raw random number and reduce it with the modulo operator - `rawInt % sides`. Done directly on a fixed-width random integer, that can subtly favour the low numbers whenever the number of sides doesn't divide evenly into the generator's range, since some remainders end up reachable by slightly more raw values than others. This tool avoids that by first turning the crypto-backed draw into a uniform float between 0 and 1, then multiplying by the number of sides and rounding down - the same approach used for every other random pick across this site's tools, from shuffling teams to spinning the picker wheel.
Every die roll here comes from the browser's cryptographically secure random source, `crypto.getRandomValues()`, rather than the ordinary `Math.random()`. Dice aren't security-sensitive, but the site uses the stronger source everywhere a tool draws winners or rolls dice anyway, since it costs nothing and removes any doubt about fairness when the results might settle a real game or a bet.
What you give it, and what you get back
| Item | Details |
|---|---|
| Dice | Number and type, d4 to d100. |
| Modifier | A positive or negative number added to the total. |
| Output | Each die, the sum and the final total. |
Issues you may run into
| What you see | Why it happens | What to do |
|---|---|---|
| Advantage is needed | It is not built in. | Roll twice and compare. |
| A custom die is needed | Only standard dice are listed. | Use a number generator with a range. |
| The total looks odd | The modifier is included. | Check the sum line. |
Assumptions and limitations
- This covers the standard polyhedral set (d4, d6, d8, d10, d12, d20, d100) - non-standard die types aren't included.
- Advantage/disadvantage (roll twice, keep higher or lower) isn't built in - roll twice manually and compare.
Frequently asked questions
How do I roll dice online for free?
Choose a die type, set how many dice and any modifier, and press Roll - every individual result and the total appear instantly.
Is this actually random?
Yes. It uses the browser's cryptographically secure random number generator for every die, the same quality used for security-sensitive purposes.
Can I roll more than one die at once?
Yes - set the number of dice to roll up to 20 of the same type at once, with the sum and total shown automatically.
How does the modifier work?
Enter a positive or negative number and it's added to the sum of all dice rolled, matching the standard tabletop notation like 2d6+3.
Is my data uploaded anywhere?
No. Rolling happens entirely in your browser - nothing is sent to a server.
Does changing the modifier re-roll the dice?
Yes. Any change to die type, dice count or modifier triggers a completely fresh roll of every die - it doesn't just reapply a new modifier to the previous roll.
Why use a cryptographically secure random source for something as low-stakes as dice?
It costs nothing and removes any doubt: ordinary Math.random() would look identical for casual play, but this site uses the browser's cryptographically secure source across every tool that rolls dice or draws winners, since results here sometimes settle real games or bets.