Dice Roller

Dice roller for d4 through d100, multiple dice and modifiers

Tap d20 to roll a twenty-sided die. Type 3d6+2 in the notation box and press Roll to throw three six-sided dice and add two to the total. Or use the builder fields to set the number of dice, the number of sides and a modifier, then roll that combination as many times as you like. The total appears in large type, the individual dice are shown beneath it whenever you roll more than one, and every roll is kept in a history list so nobody has to remember what the last attack roll was.

This is the tool for a physical dice set you do not have to hand: a game night where the d6 has gone under the sofa, a tabletop session played over a video call, a maths lesson demonstrating sums of dice, or a board game whose dice were lost years ago. It runs entirely in your browser — no account, no install, and nothing you roll is sent to a server.

Reading dice notation

Dice notation is the shorthand every tabletop rulebook uses, and this tool takes it directly. The form is NdM, optionally followed by a modifier.

The N is how many dice, the M is how many sides each one has. The modifier is applied once to the total, not once per die — this is the mistake new players make most often. 3d6+2 adds a single 2 to the sum of three dice, giving a minimum of 5 and a maximum of 20. It does not add 2 to each die, which would give a minimum of 9. Rolling the individual dice and displaying them separately, as this tool does, makes the difference visible: add up the dice shown, add the modifier once, and you have the total.

Spacing and capitalisation are forgiving — 2 D 6 + 1 parses the same as 2d6+1. What the notation box will not accept is a compound expression such as 2d6+1d4. One dice group plus one flat modifier is the grammar; roll the second group separately and add the totals yourself.

Three ways to roll

• Quick roll buttons — d4, d6, d8, d10, d12, d20 and d100, each rolling a single die of that type immediately. This is the fastest path and covers most in-game moments. Pressing one also loads that die into the builder, so you can follow it up with a multi-dice version.
• The builder — three numeric fields for number of dice (1 to 100), sides (2 to 1,000) and modifier, with a button that shows exactly what it will roll, for example Roll 3d6+2. Use this when you want to nudge one value without retyping notation. Sides is a free number, so unusual dice like a d3, d7, d14 or d30 are all available even though there is no quick button for them.
• The notation box — type any valid NdM string and press Enter or Roll. Fastest if you already think in notation, and the field keeps its value so pressing Roll again repeats the same throw.

Invalid notation produces a plain message rather than a wrong number. If you mistype, nothing is added to the history.

The result panel and the roll history

After a roll, the panel shows the modifier-adjusted total in large type, with the notation above it. When more than one die was thrown, each die's face value is listed beneath the total, so you can verify the arithmetic or apply a house rule that cares about individual dice — rerolling ones, counting how many beat a threshold, or spotting a natural maximum.

Below that, the history keeps the last thirty rolls, newest first, each showing the notation, the individual dice in brackets and the final total. This settles table arguments and lets you recover a number after somebody talked over the result. Clear wipes it. The history lives only in the open page: refresh or close the tab and it is gone, which is deliberate — nothing is stored on a server and nothing about your rolls leaves your browser.

Rolling many dice at once

The builder accepts up to 100 dice in a single throw, which covers the largest damage rolls in most systems and a good deal of statistics teaching besides. Rolling 50d6 and looking at the individual faces is a fast way to show that a large handful of dice produces a total clustered tightly around its average rather than spread evenly — the totals bunch, while any one die stays flat.

That bunching is worth understanding because it is the reason different notations feel different at the table even when they average the same. 3d6 and 1d20-1 have similar midpoints but behave nothing alike: the twenty-sided die is equally likely to give any face, so extremes are common, while three six-sided dice make middling totals far more likely than 3 or 18. A system built on d20 is swingy by design; one built on multiple d6 is predictable by design. Roll each a dozen times here and the difference is immediately obvious in the history list.

Worked examples from real games

• An attack roll with a bonus — type 1d20+5. The total is what you compare against the target number; the die face is shown so you can still see whether you rolled a natural 1 or 20.
• Damage from a greatsword — 2d6+3. Both dice are listed, then the flat 3 is added once.
• Rolling up a character stat — 4d6, then drop the lowest die yourself. The tool shows all four faces, so dropping one by eye takes a second.
• A percentile check — the d100 quick button.
• A board game that lost its dice — 2d6, over and over, with the history as your record of the turn.
• A coin substitute — set sides to 2 in the builder for a straight one-or-two result.

Is it actually random?

Each die face is drawn using the browser's built-in Math.random(), scaled to the number of sides. That is a pseudorandom generator: a deterministic algorithm the browser seeds at start-up, producing a uniform, well-distributed sequence with no pattern a player will ever detect across a game session or a hundred of them. Every face of every die is equally likely, which is more than can be said for most physical dice.

It is not cryptographically secure, and this page will not pretend otherwise. Browsers offer a separate function, crypto.getRandomValues(), that draws from the operating system's entropy pool and is designed so that observing past output reveals nothing about future output. This dice roller does not use it. So for tabletop play, teaching, board games and anything else where the stakes are fun, these dice are fair. For anything where a person could gain money or advantage by predicting the next result — gambling, a prize draw with legal weight, generating a secret — use a purpose-built source instead.

It is also worth saying what a digital die does better than a real one. Manufactured dice are not perfectly fair: injection-moulded plastic dice have hollowed pips or ink of a different density, edges wear unevenly, and cheap d20s in particular are measurably out of true. A simulated die has no geometry to be wrong about. If you have ever suspected a die at your table, this is the impartial alternative.

Why a run of bad rolls is not a broken roller

Every dice roller on the internet receives the same complaint: it rolled three 1s in a row, so it must be rigged. It almost certainly is not. Dice have no memory. After two 1s on a d20, the chance of a third is still one in twenty, exactly as it was the first time — nothing about the tool tracks what it has already produced or owes you a good roll to balance the books. Believing otherwise is the gambler's fallacy, and it is the reason players change dice mid-session and feel it helped.

Streaks are also more likely than intuition allows. Across an evening you might roll a d20 two hundred times, and in two hundred draws from twenty outcomes, unlikely-looking clusters are close to guaranteed somewhere in the sequence. You notice the run of low rolls during the boss fight and forget the run of high rolls during the shopping trip. If you genuinely want to check the roller, use the history and a large number of rolls, and look at the spread of results rather than the shape of any short stretch of them.

Related dice tools

If you play D&D and want advantage and disadvantage handled for you — two d20 rolled with the higher or lower one kept, both shown — the D&D dice roller adds those buttons. For a stripped-down single die with nothing else on screen, the d20 roller opens ready to roll. And if what you want is the distribution rather than the game — watching the sum of 2d6 build into its familiar triangular shape over thousands of trials — the dice simulator plots observed against expected results as they accumulate.

Common questions

• What dice can I roll? Anything from 2 to 1,000 sides, with quick buttons for the standard d4, d6, d8, d10, d12, d20 and d100.
• How many dice at once? Up to 100 from the builder.
• Can I combine different dice, like 2d6+1d4? Not in one expression. Roll each group separately and add the totals.
• Does the modifier apply per die? No — once, to the total.
• How much history is kept? The last thirty rolls, until you clear them or leave the page.
• Is anything uploaded? No. Rolls are generated and displayed in your browser and are never sent anywhere.