Dice Roller

This dice roller lets you roll a dice, or a whole handful, right in your browser. Pick any mix of d4, d6, d8, d10, d12, d20 and d100, up to 20 at once, and watch them tumble across the tray. You get the total, every die result, the exact odds and a timed history. It’s free, with no download or sign-up.

What the dice roller does

Each roll shows the total in big type and a breakdown of every die by group, such as “2d6: 3 5 · 1d20: 17 · +2”. A short line under it gives the average for that set and how often a total this high (or this low) comes up, worked out exactly. A 20 or a 1 on a single d20 is called a natural 20 or a natural 1.

The d6 is drawn as a cube with pips, the d4 to d20 as numbered 3D shapes, and the d100 as a round token showing 1 to 100.

How to use it

• Roll: press Roll, tap the tray or press Space. The tool opens with 2d6 ready.
• Build a set: tap a die button to add one of that type, and tap the minus next to it to remove one. The count on each button shows how many you have. Mixed sets such as 2d6 plus a d8 are fine.
• Add a modifier: the minus and plus buttons next to the notation box add or subtract a flat number.
• Use a preset: 1d6, 2d6, 1d20, Advantage, Disadvantage and 4d6 drop low each roll straight away with one tap.
• Hold and reroll: after a roll, tap any die to hold it. Held dice get a gold ring. The Roll button then reads “Reroll” with the number of free dice, and only those dice roll again. Release all, or Esc, frees them.

Dice notation

You can also type standard dice notation in the box and press Enter. The parser understands:

• NdX for N dice with X sides, for example 3d6 or d20 (one die). d% means d100.
• + and – to join groups and numbers, as in 1d20+5, 2d6+1d4-1 or 1d8-1d4.
• kh and kl to keep the highest or lowest dice. 2d20kh1 is advantage and 2d20kl1 is disadvantage. A plain k means kh.
• dl and dh to drop the lowest or highest dice. 4d6dl1 is the classic way to roll a character stat. A plain d after the dice, as in 4d6d1, means dl.

Spaces and capitals don’t matter. If something can’t be read, such as an unsupported d7, the tool says what is wrong instead of rolling. Dropped dice stay in the tray but fade out, and are struck through in the breakdown.

History and statistics

The History tab lists your last 100 rolls with the time of each, the notation, the total and every die. Rerolls with held dice are marked with a star. Tap a line to load that notation again. History is saved in your browser, and Clear history wipes it after a second tap.

The Statistics tab draws a bar for every total you have rolled this session with the current set, next to a line for the exact odds of each total. The odds count every possible outcome, including keep and drop rules, so for 2d6 the line peaks at 7 with 6 chances in 36. Rerolls with held dice are left out, since holding changes the odds.

Is it fair?

Results come from your browser’s secure random number generator (the Web Crypto API). A common shortcut, taking a random number modulo 6, makes some faces very slightly more likely. This roller throws away the few random values that would cause that bias and draws again, so every face is equally likely. The animation is only for show.

Tips

• Use the Statistics tab to see why 4d6 drop lowest gives higher stats than 3d6.
• Hold dice to play dice games by hand. For a game that does the scoring for you, try Yahtzee or Farkle.

FAQ

How many dice can I roll at once?

Up to 20 per roll, in any mix of types, plus a modifier. Sound can be turned off with the Sound button or the M key.

Can I shake my phone to roll?

On phones that share motion data without asking permission, such as most Android phones, a firm shake rolls the dice, and a note appears under the tool once motion is detected. Where the browser would show a permission prompt, as on iPhone, shaking is turned off and you tap to roll instead.

How does advantage work?

Advantage rolls two d20s and keeps the higher one (2d20kh1). Disadvantage keeps the lower one (2d20kl1). The die that doesn’t count is faded and marked dropped.