Dice Roller
Takes real dice notation, including keep-highest for character rolls.
Roll dice online using real notation: 3d6, 1d20+5, or 4d6kh3 to keep the highest three. Discarded dice are shown, not hidden, and every roll is fair.
Press roll.
The notation
3d6— three six-sided dice, added together1d20+5— one twenty-sided die plus five4d6kh3— roll four, keep the highest three, which is how role-playing characters are rolled2d10kl1— roll two, keep the lowest, the disadvantage roll1d4+1d8+2— mix any dice you like
Discarded dice are shown struck through rather than hidden, since seeing what you threw away is most of the fun of rolling four and keeping three.
Every die is drawn from the browser’s cryptographic random source, with the usual modulo bias avoided, so a d6 gives each face exactly one chance in six rather than approximately.
How the Dice Roller works
Type what you want to roll in standard notation and get it: 3d6 for three six-sided dice, 1d20+5 for a die plus a modifier, 4d6kh3 to roll four and keep the highest three. Discarded dice are shown struck through rather than hidden, since seeing what you threw away is most of the point. Every die comes from your browser's cryptographic random source with the usual modulo bias avoided, so a d6 gives each face exactly one chance in six.
Also known as: roll dice online · d20 dice roller · dnd dice roller · virtual dice · 4d6 drop lowest roller
Reading dice notation
Dice notation predates computers and is the reason a dice roller worth using takes a text field rather than a set of dropdowns. NdS means roll N dice with S sides and add them: 3d6 is the classic three six-sided dice. A modifier is written with a plus or minus, so 1d20+5 is one twenty-sided die plus five. Terms combine, so 1d4+1d8+2 is perfectly ordinary.
The suffix that matters is kh or kl, keep highest or keep lowest, followed by how many to keep. 4d6kh3 rolls four dice and keeps the best three, which is how role-playing character statistics have been generated for four decades. 2d20kh1 and 2d20kl1 are advantage and disadvantage, the mechanic that anchors modern fifth-edition play.
Most online rollers cannot express any of that, because they were built around a menu of common dice. The people who most need a dice roller are the ones who already think in notation, so they end up typing 4d6kh3 into a search box, finding a dropdown, and rolling four dice by hand instead.
What discarded dice tell you
A roller that shows only the dice it kept has thrown away the interesting half of the result. 4d6kh3 producing 6, 5, 4 and 1 feels entirely different from 6, 5, 4 and 4, even though both keep the same fifteen. The first was lucky; the second wasted a good die.
So every die rolled is displayed, with the discarded ones struck through rather than removed. It costs nothing and it is the difference between a number appearing and a roll happening.
The extremes are marked too, since a natural maximum or a natural 1 usually carries its own meaning at the table quite apart from the arithmetic.
Are physical dice fair?
Cheap dice frequently are not, and the reason is how they are made. An injection-moulded die has its pips hollowed out and filled with paint, which is lighter than the plastic it replaced. The six face loses six pips' worth of material and the one face loses one, so the die is very slightly biased toward landing six-up. The moulding process also leaves a seam and small variations in edge radius.
Casino dice are made differently and cost accordingly: machined to tolerances measured in thousandths of an inch, with pips drilled and filled flush using material of the same density, sharp edges rather than rounded, and often transparent so tampering shows. They are also retired regularly, because wear reintroduces the bias.
None of which is a reason to distrust the dice in your board game, where a fraction of a percent will never be noticed. It is a reason not to assume that a physical die is the gold standard a digital one is approximating. This one draws each die from the browser's cryptographic random source, and the arithmetic that turns a random value into a face rejects the values that would make low faces marginally more likely, so a d20 gives each face exactly one chance in twenty rather than approximately.
Frequently asked questions
What does 4d6kh3 mean?
Roll four six-sided dice and keep the highest three. It is how role-playing character statistics have been rolled for forty years, and it is the thing most online dice rollers cannot express, because they offer a dropdown of dice rather than reading notation.
What notation is supported?
NdS for N dice of S sides, a bare dS for one die, plus and minus for modifiers and for combining terms, and kh or kl followed by a number to keep the highest or lowest dice. So 1d4+1d8+2 and 2d10kl1 both work.
Is it fair?
Every die is drawn from the browser's cryptographic random source. Turning a random value into a number from 1 to 20 is where fairness usually leaks, because taking a remainder makes the low faces slightly more likely whenever the range does not divide evenly. Values landing in the uneven tail are discarded and redrawn instead.
Are physical dice fair?
Cheap ones frequently are not. Injection-moulded dice with hollowed pips have slightly less material on the higher faces, and the moulding leaves a seam. Casino dice are machined to tight tolerances with flush painted pips for exactly this reason, and cost accordingly.
Why show the dice I discarded?
Because it is the interesting part. A 4d6kh3 that discarded a 5 feels very different from one that discarded a 1, and a roller that shows only the survivors hides the whole story of the roll.