Tool
Dice Roller
Roll d4 to d20, multiple dice at once — built for tabletop games.
Dice Roller
Roll anything from a 4-sided die to a 20-sided die, one at a time or several at once -- built specifically for tabletop games where the exact odds of each face matter.
True per-face fairness, not an approximation.
Rolling five d6s for a damage total works the same fair way as rolling a single d20 for an attack check.
How the Dice Roller works — and why it's fair
Each die face is drawn using rejection sampling over exactly N faces, where N is whatever die size you chose (4, 6, 8, 10, 12, or 20). This matters concretely for a d20: 256 possible byte values don't divide evenly by 20 (256 divided by 20 leaves a remainder of 16), so a naive byte-modulo-20 approach would make the numbers 1 through 16 each very slightly more likely than 17 through 20. Rejection sampling avoids that specific skew by discarding the leftover 16 byte values and redrawing, using crypto.getRandomValues as the underlying random source, so all 20 faces land with a genuinely identical 1-in-20 chance.
That exactness is the actual point for tabletop use: in games like Dungeons & Dragons, a natural 20 (critical success) and a natural 1 (critical failure) are meant to happen exactly 1 in 20 times each -- a die-rolling tool with even a small statistical skew would quietly shift those odds over the course of a long campaign, which is exactly the kind of subtle unfairness rejection sampling is built to eliminate.
Rolling multiple dice at once (say, 3d6 for stat generation) draws each die independently with its own rejection-sampling pass, so adding more dice to a roll never changes the fairness of any individual die in that roll.
One more probability note worth having concretely: rolling two d6 dice together (as in many board games) doesn't give a flat distribution across 2 through 12 -- 7 is the most common total because more face-combinations add up to 7 than to any other number, even though each individual die remains perfectly fair on its own.
What people roll dice for here
Tabletop RPG players use it as a backup or primary dice tool for D&D and similar systems, including rolling multiple dice at once for damage rolls. Board game players use it when a physical die goes missing. It also doubles as a probability teaching tool, since the exact per-face odds make it useful for demonstrating real dice math.
Some game masters use it specifically because a digital roll can't be visually influenced by how it's thrown or which surface it lands on, which matters for high-stakes rolls players want to trust completely.
For a binary yes/no-style decision instead of a numbered roll, the coin flip is the simpler equivalent; for a themed set of fixed answers instead of a number, the Magic 8-Ball offers that.
Math teachers sometimes use a batch of rolled d6 pairs as a live demonstration of that exact non-uniform two-dice-sum distribution, since it's a common source of confusion that a fair pair of dice doesn't produce a flat, all-equal distribution of totals.
Frequently asked questions
Is a physical die actually less fair than this?
Real dice can have tiny manufacturing imperfections -- uneven weight distribution or rounded edges -- that introduce small, measurable biases; a well-implemented digital roll using rejection sampling avoids that specific problem.
Can I roll with a modifier, like d20+3?
You can roll the die and add your modifier afterward; the tool's job is generating the fair raw roll.
Does it support rolling with advantage or disadvantage (roll two, keep higher/lower)?
You can roll multiple dice at once and apply that rule yourself to the results shown.
What die sizes are supported?
d4, d6, d8, d10, d12, and d20 -- the standard tabletop set.
Does rolling several dice at once change the odds of any single die?
No -- each die in a multi-die roll is drawn independently with its own fair rejection-sampling pass.
Why isn't the sum of two d6 dice evenly distributed even though each die is fair?
Because more combinations of the two dice add up to middle values like 7 than to extreme values like 2 or 12 -- the individual dice are fair, but their sum naturally clusters toward the middle.
Can I roll unusual combinations, like 2d10?
Yes -- roll multiple dice of the same size at once and read each independent result.