Dice Roller: Roll Any Combination of Dice

How to use the dice roller

1. Type your roll in NdS+M notation into Set 1, where N is the number of dice, S is the number of sides and M is an optional modifier. For example, 2d6+3 rolls two six-sided dice and adds three.
2. Fill in Set 2 through Set 5 if you need to roll multiple groups at once, such as rolling damage for several attacks simultaneously.
3. Press Roll to generate the results. Each set shows the individual die values, the modifier applied and the final total.

Understanding NdS+M Notation

The standard notation for tabletop gaming is NdS+M. N represents how many dice to roll, S represents the number of sides on each die and M is a flat modifier added or subtracted from the sum.

For example, 3d8+2 means you roll three eight-sided dice, add their face values together and then add two more. If the rolls are 5, 2 and 7, the calculation is 5 + 2 + 7 + 2 = 16. A negative modifier works the same way: 1d20-1 subtracts one from the result.

You can also combine different dice types in a single expression. Writing 1d8+1d6+3 rolls one eight-sided die and one six-sided die, sums them and adds three. The parser reads every term separated by a plus or minus sign.

Common Dice Types

Tabletop roleplaying games use a standard set of polyhedral dice. Here is a reference table of the most common types and what they are typically used for.

This dice roller supports all of these sizes. When people search for a d20 roller or a d6 roller, they are looking for exactly this kind of tool that handles specific polyhedrals accurately.

How Randomness Works

A fair physical die gives each face an equal probability of landing face up. To replicate this digitally, this online dice tool uses the Web Crypto API rather than the standard JavaScript Math.random() function.

The crypto.getRandomValues() method provides cryptographically secure random numbers. The logic generates a 32-bit unsigned integer and uses the modulo operator to map it to the correct range of sides. While modulo introduces a microscopic bias when the range does not evenly divide 2^32, for dice with 100 or fewer sides this bias is far smaller than the physical imperfections in a real plastic die.

Because the randomness is generated locally, no server is involved. Every roll happens instantly inside your browser session.

Probability Basics for Dice

Understanding the math behind your rolls helps you make better decisions during gameplay. A single die produces a uniform distribution, meaning every face has an equal chance. A d20 has a 5 percent chance for each number from 1 to 20.

When you roll multiple dice and sum them, the distribution changes from uniform to a bell curve. Rolling 2d6 yields results from 2 to 12, but a 7 is six times more likely than a 2 because there are six combinations that sum to 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) and only one combination that sums to 2 (1+1).

This is why systems that use multiple dice for damage feel more predictable than those using a single large die. If you just need a simple binary outcome instead of a range of numbers, a coin flip might be more appropriate than rolling dice.

Practical Uses Beyond Tabletop Games

While roleplaying games are the most popular reason to roll dice, they are useful in many other contexts. Board game players frequently need to simulate rolls when playing digital adaptations or testing strategies without setting up the physical box.

Teachers use dice for classroom probability exercises and random group assignments. Game developers use them to test loot drop rates and balance mechanics before writing automated simulations.

If you need to pick a random person from a group rather than generating a number, a random name picker is a better fit. For shuffling items into a random order, try a list randomizer. And if you simply need a yes or no answer, a yes or no generator skips the math entirely.

Worked examples

Each result below was produced by the same code the tool runs, so you can check your own numbers against them.