Dice Roller

What is a dice roller?

A dice roller is a virtual set of dice that gives you random numbers exactly like real dice. This online dice roller lets you roll from 1 to 10 dice at a time and choose the dice type — the standard six-sided d6 used in Ludo, Snakes and Ladders and Monopoly, or the d4, d8, d10, d12, d20 and d100 used in tabletop role-playing games like Dungeons & Dragons. It adds up the total for you, applies an optional modifier, animates the roll and keeps a history of every result.

It is handy when you have lost the dice from a board game, when you need dice types you do not own, or when you are playing online with friends and everybody needs to see the same roll.

How to use this tool

1. Choose how many dice to roll, from 1 to 10.
2. Choose the dice type — d4, d6, d8, d10, d12, d20 or d100.
3. Add a modifier if your game needs one, for example +3 for a bonus or −1 for a penalty. Leave it at 0 for a plain roll.
4. Press Roll dice. The dice shake, then show the final faces with the total and the full working, such as "2d6: 4 + 5 = 9".
5. Check the history for earlier rolls and copy it if you need a record.

How the dice roll works

For each die with s sides, the tool takes a 32-bit number from crypto.getRandomValues(), throws away the small top slice that would make some faces more likely (rejection sampling) and maps the rest to a face from 1 to s. Every face therefore has exactly the same probability, 1/s, and each die is independent of the others. The animation is cosmetic — the result is fixed before the dice start to shake.

The "possible range" is n + modifier to n × s + modifier, and the average roll is n × (s + 1) / 2 + modifier.

Worked example: for 2d6 the range is 2–12 and the average is 2 × 7 / 2 = 7. There are 36 equally likely combinations and six of them total 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1), so P(7) = 6/36 = 16.7%, while P(2) and P(12) are only 1/36 = 2.8% each. For 1d20+5 the range is 6–25 and the average is 10.5 + 5 = 15.5.

Chance of rolling a specific number

For one fair die with s sides, the chance of any single face is 1/s: 16.7% for a given number on a d6 and 5% for a natural 20 on a d20. To find the chance of getting a particular face at least once in several rolls, work out the chance of missing it every time and subtract from 1. In Ludo you often need a 6 to bring a piece out: the chance of at least one 6 in 4 rolls is 1 − (5/6)⁴ = 1 − 0.482 = 51.8%, so about half the time a player still has no 6 after four turns. With advantage in D&D (roll 2d20, keep the higher), the chance of a natural 20 rises to 1 − (19/20)² = 9.75%, almost double a single roll.

Dice types and where they are used

• d4 — small damage rolls in role-playing games.
• d6 — Ludo, Snakes and Ladders, Monopoly, Yahtzee and most family board games.
• d8, d10, d12 — weapon damage and hit points in RPGs.
• d20 — attack rolls, saving throws and skill checks in Dungeons & Dragons and similar games.
• d100 — percentile rolls (1–100), random tables and probability exercises.

Tips

• Use 2d6 for Monopoly and Catan style games where the sum matters — notice how 7 comes up far more often than 2 or 12.
• For advantage in D&D 5e, roll 2d20 and keep the higher die; for disadvantage keep the lower. Both values are listed in the result line.
• Use the copy button to paste rolls into a group chat when playing remotely.
• For maths classes, roll 10d6 many times and compare the totals to the expected average of 35.

Limitations & notes

Real physical dice are rarely perfectly balanced, so this virtual roller is actually closer to an ideal fair die. The tool rolls up to 10 dice of one type at a time and supports a single whole-number modifier from −100 to 100; for mixed pools (such as 1d8 + 2d6) roll each type separately and add them. History stays in this page only and clears when you refresh.

Frequently Asked Questions

Is this online dice roller fair?

Yes. Each die uses the browser's cryptographic random number generator with rejection sampling, so every face has exactly the same chance and each roll is independent.

What does 2d6 or 1d20+5 mean?

The number before d is how many dice, the number after d is how many sides each die has, and anything after a plus or minus is a modifier added to the total. 2d6 means two six-sided dice; 1d20+5 means one twenty-sided die plus 5.

What is the most common total with two dice?

Seven. Six of the 36 possible combinations add up to 7, giving a probability of about 16.7%. Totals of 2 and 12 are the rarest at about 2.8% each.

How do I roll a d100?

Choose d100 (percentile) as the dice type. The tool returns a number from 1 to 100, each with a 1% chance, which is the same as rolling two percentile d10s.

Can I roll dice for Ludo or Snakes and Ladders?

Yes. Choose 1 die of type d6 and press Roll dice for each turn. Choose 2 dice for games like Monopoly that use the sum of two dice.

Why do the dice shake before showing the result?

The shake is only an animation to make rolling feel natural. The final result is decided before the animation starts, and users who prefer reduced motion see the result almost immediately.

Related tools

Coin Flip · Spin the Wheel · Probability Calculator · Random Number Generator · Decision Maker