Dice Roller

How this dice roller works

Each roll uses the Web Crypto API (crypto.getRandomValues) to generate a cryptographically secure random value for every die, mapped evenly across the number of faces you chose. Nothing is precomputed or repeated — every roll happens fresh, locally in your browser.

Standard dice sizes

Die	Faces	Common use
d4	4	Damage rolls in tabletop RPGs
d6	6	Classic board games (Monopoly, Yahtzee)
d8	8	Tabletop RPGs
d10	10	Percentile rolls, RPGs
d12	12	Tabletop RPGs
d20	20	Dungeons & Dragons core mechanic

How to use this dice roller

1. Pick how many dice to roll (1–6).
2. Pick the number of sides per die (d4–d20).
3. Press Roll — each die's result and the total are shown instantly.

Probability basics

Every face of a fair die has an equal chance of landing: 1-in-6 for a single d6, 1-in-20 for a single d20, and so on. Rolling more than one die changes the picture for the total, though — with two d6, there's only one way to roll a 2 (1+1) but six ways to roll a 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1), which is why 7 is the most common sum in games like Monopoly and craps, even though every individual die stays perfectly fair.

Frequently asked questions

Is this dice roller truly random? Yes — it uses the Web Crypto API (crypto.getRandomValues), a cryptographically secure random number source built into your browser, rather than a predictable pseudo-random generator.

What dice sizes are supported? d4, d6, d8, d10, d12, and d20 — the standard set used in tabletop games like Dungeons & Dragons — with 1 to 6 dice rolled at once.

Can I use this for board games instead of physical dice? Yes — it works well as a substitute when dice are missing, lost, or you're playing remotely with others.

Does it store or share my rolls? No — every roll happens locally in your browser and nothing is saved or transmitted.

What's the probability of rolling any specific number on a d20? Exactly 1 in 20 (5%) for each face, since a fair d20 gives every outcome an equal chance.

Why do some totals come up more often when rolling two dice? Because more combinations of the two dice add up to certain totals — for two d6, there's only one way to make 2 or 12, but six ways to make 7, so middle totals appear far more often over many rolls.

Dice notation, probability and tabletop use

Reading dice notation

Game rules write dice as NdS, where N is how many dice to roll and S is the number of sides. So 3d8 means roll three eight-sided dice and add them, and 2d6 + 3 means roll two six-sided dice, add them and then add 3. Choose the dice type and count in the roller to match the notation, then add any modifier yourself.

Probability of totals on two six-sided dice

Total	Ways to roll it	Chance
2 or 12	1	2.8%
3 or 11	2	5.6%
4 or 10	3	8.3%
5 or 9	4	11.1%
6 or 8	5	13.9%
7	6	16.7%

Out of 36 possible combinations, seven is the most likely total, which is why it is so important in games such as craps and Catan.

Everyday uses

• Role-playing games and board games when you have lost your dice.
• Making quick random choices, like who goes first.
• Teaching probability in the classroom with large numbers of rolls.
• Using the d20 for rules such as advantage, where you roll twice and keep the higher result.

More questions

What does advantage mean in D&D? You roll two twenty-sided dice and use the higher result. With disadvantage you use the lower one.

Do dice have a memory? No. Past rolls do not affect future ones, so a number is never due after a streak without it.