Dice Roller

Roll Any Dice—Any Number of Sides, Any Number of Dice

Physical dice are convenient until they're not — they fall under furniture, the dog considers them a snack, and the specific polyhedral die you need for a particular game rule isn't in the box. Our virtual dice roller handles any number of sides from 2 to 100, in any quantity from 1 to 20. Set your sides and count, click roll, and get individual results plus the total instantly.

The randomness uses your browser's built-in cryptographic random number generator — the same source used in security applications — which means results are genuinely unpredictable and unbiased, unlike simpler pseudo-random implementations.

Standard Dice Types and When You'd Use Each

Tabletop RPGs and board games have standardized around a specific set of polyhedral dice that have become the vocabulary of tabletop gaming. Each has its role.

D4 (4 sides) — A tetrahedron, the most awkward physical die because it doesn't really roll so much as tumble. Used in D&D for damage from small weapons like daggers and for certain spells. Less common than the others but essential for completeness.

D6 (6 sides) — The standard cube die, the one everyone has. Board games, craps, Yahtzee, Settlers of Catan, and countless other games use the D6 as their primary randomizer. In RPGs, it appears for damage, hit points, and attribute generation. Multiple D6 rolls (2d6, 3d6, 4d6 drop lowest) are standard for character creation.

D8 (8 sides) — An octahedron. Common in D&D for damage from medium weapons like longswords and handaxes, and for hit point calculations for Ranger and Druid classes.

D10 (10 sides) — Technically a pentagonal trapezohedron. Used in D&D for heavy weapons and for some class hit dice. Paired with a second D10 labeled 00–90 to form a D100 (percentile roll). Also the basis of the World of Darkness / Storyteller system, which uses pools of D10s.

D12 (12 sides) — A dodecahedron. Less commonly used than the others; in D&D it's the damage die for battleaxes and greataxes, and the Barbarian class hit die. More prominent in some other RPG systems.

D20 (20 sides) — The most iconic die in tabletop RPG culture. In D&D, virtually every important check — attacks, saving throws, ability checks — uses the D20. Roll high and succeed; roll low and fail. Rolling a natural 20 (the maximum) is a critical hit or critical success; rolling a 1 is a critical failure. The D20 is so central to D&D that the game's current edition is literally called the D20 System.

D100 (percentile) — Used for probability checks expressed as percentages. Some game systems use percentile rolls for skill checks where you succeed if you roll under your skill score. Also used in tables where you roll to determine a random encounter, weather effect, treasure type, or other outcome from a list of 100 options.

Notation: Understanding 2d6, 3d8+5, and Similar Expressions

Tabletop RPG rules express dice rolls in a compact notation that becomes second nature quickly. The format is [number of dice]d[sides][modifier].

2d6 means roll 2 six-sided dice and add the results. Average result: 7. Range: 2–12.

4d6 drop lowest means roll 4 six-sided dice, discard the lowest result, and add the remaining three. This is the standard method for generating D&D ability scores — it skews the distribution toward higher numbers compared to 3d6.

1d20+5 means roll one twenty-sided die and add 5 to the result. The +5 represents a modifier from the character's ability score or proficiency bonus. Attack rolls and saving throws are typically expressed this way.

2d8+1d6 means roll two eight-sided dice and one six-sided die and add all results together. This appears in damage expressions for magical weapons or combined attacks.

Our roller handles the first part of any expression — you set the number of dice and the sides. To apply modifiers, add them to the total displayed after rolling.

Uses Beyond Tabletop Gaming

Dice are randomization tools with applications anywhere you need a random integer within a range. Teachers use dice rolls to randomly assign students to groups, select discussion questions, or determine the order of presentations. Probability and statistics students use dice to explore sampling distributions, law of large numbers, and expected value through experimentation rather than calculation alone. Game designers test probability distributions of their mechanics by rolling large numbers of dice virtually rather than physically. Developers testing random-number-dependent code use dice as a quick sanity check that their distributions look right. And plenty of people use dice for everyday decisions — which restaurant to try from a shortlist, which book to read next, which item on a to-do list to tackle first.

The Mathematics of Dice Probability

A single fair die has a uniform distribution — each face has an equal probability of appearing. For a D6, each result from 1 to 6 has a 1/6 ≈ 16.7% probability. For a D20, each result from 1 to 20 has a 1/20 = 5% probability. The expected value (average) of a single die is (sides + 1) / 2. A D6 averages 3.5; a D20 averages 10.5.

When you roll multiple dice and add them, the distribution changes from uniform to roughly bell-shaped. Rolling 2d6 produces sums from 2 to 12, but not with equal probability — 7 is the most likely result (6 ways to roll it out of 36 possible combinations) while 2 and 12 are least likely (1 way each). The more dice you add, the more the distribution concentrates around its average. This is the central limit theorem at work: sums of independent random variables tend toward a normal distribution as the number of variables increases.