What dice types are supported?

The roller supports all standard polyhedral dice: d4, d6, d8, d10, d12, d20, and d100 (percentile). You can roll up to 20 dice of any type simultaneously with a positive or negative modifier added to the total.

How is the percentile calculated?

The percentile represents what fraction of all possible outcomes for your roll combination are at or below your result. It's calculated by enumerating the full probability distribution and finding your result's cumulative probability. A 50th percentile roll is exactly average — half of outcomes would be lower, half higher.

Are the rolls truly random?

Yes — the roller uses the browser's Web Crypto API (window.crypto.getRandomValues) for cryptographically secure randomness, the same standard used for security applications. This is significantly more random than standard Math.random(), which is a pseudorandom generator not suitable for applications requiring true unpredictability.

What is advantage and disadvantage in D&D?

Advantage means rolling two d20s and taking the higher result; disadvantage means rolling two and taking the lower. Use the 2d20 preset and read the individual die results — the probability panel shows the distribution for both dice so you can quickly see how much advantage shifts the odds in your favor.

How does the probability distribution chart work?

The chart shows every possible total for your dice configuration on the x-axis and the probability of rolling exactly that total on the y-axis. For a single d6 this is uniform (each face = 16.7%). For multiple dice the distribution becomes bell-shaped — the middle values become far more likely than the extremes. This explains why 10-11 on 3d6 is much more common than 3 or 18.

🔧Utilities

Dice Roller — Any Combination with Probability Analysis

What number will you roll?

What This Does

Roll any combination of standard polyhedral dice (d4 through d100) with an optional modifier and instantly see your result, percentile rank, probability distribution, and full roll history. This isn't just a basic dice roller — it shows you what your result means. If you roll 4d6+8 and get 24, is that good? The probability panel answers that: 24 falls at the 65th percentile for that roll, meaning you'd expect to beat it only 35% of the time. Full probability distribution shows every possible total alongside its likelihood. RPG presets cover the most common D&D and Pathfinder roll types so you can jump straight into gameplay without configuring each roll manually. The roll history panel tracks your last ten rolls so you can spot patterns across a session — useful for confirming whether a weapon consistently underperforms or you are just running cold. Works on mobile during tabletop sessions or on desktop for virtual tabletop play.

When Should You Use This?

→Rolling for damage, initiative, ability scores, or saving throws in D&D, Pathfinder, or other TTRPGs
→Simulating board game dice rolls to understand probability of outcomes
→Teaching probability concepts using concrete dice examples
→Settling disputes about how likely a particular dice outcome actually is
→Running multiple dice rolls quickly during online tabletop sessions

Example Scenario

Marcus is playing D&D 5e online and rolls sneak attack damage — 4d6+8. He rolls: 3, 5, 2, 6 = sum 16 + modifier 8 = 24 total. The probability panel shows 24 is the 65th percentile for this roll combination — above average but not exceptional. Roll history tracks his last 10 rolls so he can spot hot or cold streaks across the session.

🎲Dice Roller

Dice Roller & Probability Analyzer

Configure any dice combination, see probability distributions before you roll, then get charts, percentile scores, and history. Hit Roll to generate your result.

Quick Presets