Dice Roller
Roll virtual dice online. Supports d4, d6, d8, d10, d12, d20, d100, and custom dice. Roll multiple dice simultaneously.
About the Dice Roller
A dice roller is a digital tool that simulates the throw of one or more dice, producing results that are mathematically equivalent to rolling physical dice — but faster, always available on any device, and provably fair. With 481,000 monthly searches, the online dice roller is one of the most searched gaming tools on the internet, fuelled by the explosive growth of tabletop role-playing games like Dungeons and Dragons, Pathfinder, and Call of Cthulhu, as well as board gaming and virtual game nights. Our free online dice roller supports every standard gaming die: d4 (four-sided), d6 (the classic six-sided cube), d8 (eight-sided), d10 (ten-sided), d12 (twelve-sided), d20 (twenty-sided, the iconic D&D die), and d100 (percentile, rolled as two d10s). It also supports any custom die — d3, d7, d30, or any other — for games with unusual dice requirements. You can roll multiple dice simultaneously with modifiers (3d8+5 for fireball damage, 2d6+3 for a sword attack), apply D&D 5e advantage and disadvantage mechanics, generate full character stat arrays (4d6 drop lowest, six times), and review a complete roll history for your entire gaming session. The randomness engine uses the browser's Web Crypto API — the same cryptographic-quality entropy source used for security applications — making every single roll genuinely unpredictable, unlike simple pseudorandom implementations.
Formula
Single die: P(x) = 1/N for each face | 2d6 mean = 7 | Advantage 2d20 mean = 13.8 | Disadvantage 2d20 mean = 7.2 | 4d6 drop lowest mean = 12.2
How It Works
Each die roll generates a cryptographically secure random integer uniformly distributed across [1, N], where N is the number of faces. Every face has exactly equal probability: 1 divided by N. For 2d6 (two six-sided dice summed): the result ranges from 2 to 12. The most probable result is 7 — there are six ways to roll a 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) out of 36 total combinations = 16.7% probability. The least probable are 2 and 12, each with only one combination = 2.8%. This distribution is important for games like Settlers of Catan where 6 and 8 are the highest-production numbers. Advantage rolls (D&D 5e): roll 2d20 and keep the higher value — this shifts the average from 10.5 to approximately 13.8 and dramatically increases the probability of success on any skill check or attack. Disadvantage: roll 2d20 and keep the lower result, reducing the average to approximately 7.2. For 4d6 drop lowest (standard D&D ability score generation): dropping the lowest die from four d6 rolls shifts the average from 10.5 to approximately 12.2, producing the heroic characters the D&D system is designed around.
Tips & Best Practices
- ✓D&D 5e character creation: roll 4d6, discard the lowest result, record the sum — repeat six times to generate your six ability scores. Our roller automates the entire process with one click including the drop-lowest mechanic.
- ✓7 is the most common 2d6 result at 16.7% probability — crucial knowledge for Settlers of Catan, where the robber activates on 7 and production numbers 6 and 8 are most valuable.
- ✓Critical hits in D&D 5e occur on a natural 20 result — exactly a 5% chance per attack roll. With advantage (rolling 2d20 taking the higher), the crit probability jumps to approximately 9.75% — nearly double.
- ✓The d20 is the heart of the D&D system: every +1 bonus represents exactly a 5% increased chance of success — this elegant math makes every ability modifier and proficiency bonus feel meaningful and impactful.
- ✓For virtual tabletop platforms like Roll20, Foundry VTT, and Fantasy Grounds, our roll history feature lets the Dungeon Master share results with players for full transparency and trust at the table.
- ✓Roll a dice online when physical dice are unavailable: late-night gaming sessions, travel, video call game nights, or simply when your bag of dice is in another room.
- ✓Probability insight for skill checks: if you need to roll 15 or higher on a d20, your base success chance is 30%. Adding a +3 proficiency or ability bonus raises it to 45% — illustrating why character progression matters mechanically.
- ✓For educational probability lessons: rolling a d6 sixty times and recording results is a classic demonstration of how observed frequencies converge toward theoretical probability as sample size increases.
Who Uses This Calculator
Dungeons and Dragons players use the dice roller for every game mechanic: generating ability scores during character creation, rolling attack and damage dice in combat, making skill checks and saving throws, determining initiative order, and rolling on random encounter and treasure tables. Pathfinder, Call of Cthulhu, Shadowrun, Vampire: The Masquerade, and hundreds of other tabletop RPG systems all use polyhedral dice that this tool fully supports. Board game enthusiasts use it when physical dice are lost, suspected of being biased, or simply unavailable. Online game groups using Discord, Zoom, or virtual tabletop platforms like Roll20 or Foundry VTT use it as a shared neutral dice tool all players can see. Teachers and professors incorporate dice rolling in probability lessons, random sampling demonstrations, and game-based learning activities. Game designers use it extensively during playtesting to simulate thousands of combat scenarios and verify that their system's probability curves feel appropriate in actual play. Statisticians use repeated dice rolling to demonstrate the law of large numbers, the central limit theorem, and frequentist probability concepts to students and colleagues.
Optimised for: USA · Canada · UK · Australia · Calculations run in your browser · No data stored
Frequently Asked Questions
What dice do I need for D&D 5e?
D&D 5e uses 7 standard dice: d4 (damage for daggers/spells), d6 (short swords, sneak attack), d8 (longswords, healing), d10 (heavy crossbows), d12 (greataxes), d20 (ability checks, attacks, saving throws), and d100/percentile (wild magic, random tables). The d20 is by far the most frequently rolled.
What is advantage and disadvantage in D&D?
With advantage, you roll 2d20 and take the higher result. With disadvantage, you roll 2d20 and take the lower result. Rolling with advantage effectively adds +3.3 to your average roll. The dice roller supports rolling 2d20 simultaneously so you can apply advantage/disadvantage easily.
How do I roll stats for D&D character creation?
The standard method (4d6 drop lowest): roll 4d6, remove the lowest die, sum the remaining three. Repeat 6 times to get scores for Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma. Average result per stat is approximately 12.2. The roller can simulate this method.
What is a critical hit in D&D?
A critical hit occurs when you roll a natural 20 on a d20 attack roll. On a crit, you roll all the attack's damage dice twice and add them together. Example: a Longsword normally deals 1d8 damage — on a crit you roll 2d8. Some class features allow crits on 19–20 or even 18–20.
How do I use dice for Pathfinder, Warhammer, or other tabletop games?
Most tabletop RPGs use the standard polyhedral set (d4, d6, d8, d10, d12, d20, d100). Warhammer Fantasy uses d6 and d10 pools. Call of Cthulhu uses d100 (percentile) for skill checks. Our dice roller supports all standard die types and custom dice up to any number of sides.
What does rolling 2d6 or 3d8 mean?
The number before "d" is how many dice to roll, the number after "d" is the die type. 2d6 = roll two six-sided dice and add results (range 2–12, average 7). 3d8 = roll three eight-sided dice and add (range 3–24, average 13.5). The roller lets you specify any combination of multiple dice.
Is an online dice roller truly random?
Online dice rollers use cryptographically secure pseudo-random number generators (CSPRNG) or browser-native Math.random(), which produces statistically uniform results across millions of rolls. For tabletop gaming purposes, this is indistinguishable from physical dice — each face has an equal probability of appearing.
Can I use this dice roller for board games like Monopoly or Yahtzee?
Yes — standard d6 dice work for Monopoly, Yahtzee, Catan, Backgammon, and most board games. For Yahtzee, roll 5d6 simultaneously. For Catan, roll 2d6. The dice roller displays individual die results and the total, exactly as you would see with physical dice.
What is a d100 and how is it used?
A d100 (percentile die) generates a number from 1–100. It is typically rolled as two d10s — one representing tens digits (00, 10, 20...90) and one representing units (0–9). A roll of 00+0 = 100, 30+5 = 35, etc. Used in D&D wild magic tables, Call of Cthulhu skill checks, and random encounter tables.
How do I roll dice for Dungeons & Dragons critical damage?
For a critical hit, double all damage dice before adding modifiers. A rogue's Sneak Attack dealing 4d6 normally becomes 8d6 on a crit, then add the Dexterity modifier once (not doubled). Select the appropriate dice type, set the count to double, roll, then add your modifier separately.