How to use it· 5 steps
- Type a roll such as 2d6, d20 or 3d6+2 — or press the d4 to d100 buttons to add dice, and +1 or −1 for the modifier.
- Or choose a common roll: advantage, disadvantage, ability score or percentile.
- Press Roll, or Enter in the box.
- Read each die, the total and the working; dropped dice are shown faded.
- Earlier rolls stay listed underneath for the rest of the session.
Step by step
How to use the dice roller
- 1Type a roll such as 2d6, d20 or 3d6+2 — or press the d4 to d100 buttons to add dice, and +1 or −1 for the modifier.
- 2Or choose a common roll: advantage, disadvantage, ability score or percentile.
- 3Press Roll, or Enter in the box.
- 4Read each die, the total and the working; dropped dice are shown faded.
- 5Earlier rolls stay listed underneath for the rest of the session.
Reading dice notation
Dice notation packs a roll into a few characters. 'NdM' means roll N dice with M sides each, so 3d6 is three six-sided dice and d20 — the N is optional — is one twenty-sided die. A plus or minus adds or subtracts: 1d20+5 is one d20 plus five, and 2d8+1d6-1 mixes dice and a modifier. 'd%' is a percentile die, the same as d100.
Keep and drop rules choose which dice count. 'kh' keeps the highest and 'kl' the lowest, so 2d20kh1 rolls two d20s and keeps the better; 'dl' drops the lowest and 'dh' the highest, so 4d6dl1 — the same as 4d6kh3 — rolls four dice and ignores the worst. Dropped dice still appear in the result, faded, so you can see everything that was rolled.
The odds behind common rolls
One die is flat: each face of a d20 comes up 5% of the time. Add dice together and the totals bunch towards the middle. With 2d6, seven is the most likely total at one in six (16.7%), while two or twelve are one in 36 (2.8%) — which is why the robber in Catan moves on a seven. With 3d6 the curve becomes a bell: 10 and 11 each turn up 12.5% of the time, and a 3 or an 18 is a 1-in-216 event (0.46%).
Keeping the better of two d20s — advantage in Dungeons & Dragons fifth edition — raises the average from 10.5 to 13.825 and the chance of rolling 11 or more from 50% to 75%. Disadvantage, keeping the worse, drops the average to 7.175 and that chance to 25%. Four d6 dropping the lowest, the classic way to roll ability scores, averages 12.24 rather than the 10.5 of plain 3d6. The roller shows the possible range and the exact average for whatever you type, worked out from every possible outcome rather than estimated.
Virtual dice versus real ones
Real dice are only as fair as their manufacture. Rounded corners, pips drilled to different depths and slightly uneven sides can favour some faces, which is why casino dice are precision-made with sharp edges and filled pips. A virtual die has none of those problems: each face of each die is one unbiased draw from crypto.getRandomValues, with rejection sampling so that a d6, for example, is not even fractionally more likely to show low numbers.
The tumble animation is there for the feel of it and is skipped if your device asks for reduced motion. The values are fixed the moment you press Roll.
Board games, tabletop RPGs and classrooms
Lost the dice from a board game? 2d6 covers Monopoly and Catan, and 1d6 covers Ludo, snakes and ladders and most children's games. For tabletop roleplaying games every standard polyhedral die is here — d4, d6, d8, d10, d12, d20 and d100 — along with keep and drop rules for advantage, disadvantage and stat generation, without the mental arithmetic.
Teachers use dice rollers for probability lessons: roll 2d6 fifty times, tally the totals, and compare the result with the distribution above. The list of earlier rolls keeps every roll of the session for exactly that.
Limits and privacy
Up to 100 dice per roll, dice from d2 up to d1000, and up to 12 parts in one expression. The exact average is shown for any plain roll and for keep or drop rolls small enough to enumerate in full (up to 50,000 combinations); larger ones show the range only. Rolling happens entirely in your browser — nothing is sent anywhere, and the history disappears when you leave the page.
Some systems use mechanics this roller does not do: exploding dice that roll again on their highest face, rerolling ones, or counting successes in a dice pool. For those, roll the dice here and apply the rule by eye — every individual face is shown for exactly that reason.
Answers
Frequently asked questions
How do I roll with advantage or disadvantage?
Use 2d20kh1 for advantage (keep the higher of two d20s) and 2d20kl1 for disadvantage, or press the buttons under Common rolls.
What does 4d6dl1 mean?
Roll four six-sided dice and drop the lowest. It is the usual way to roll D&D ability scores, and averages about 12.24.
Can I add a modifier?
Yes. Type it, as in 1d20+5 or 2d6-1, or use the +1 and −1 buttons.
What is d%?
A percentile die: a number from 1 to 100. Typing d100 gives the same thing.
Are the dice fair?
Each die is an unbiased draw from your browser's cryptographic random generator, so every face is exactly equally likely — fairer than most physical dice.
How many dice can I roll at once?
Up to 100 per roll, with any number of sides from 2 to 1,000.
Can I roll a d3, d7 or other unusual die?
Yes. Any number of sides from 2 to 1,000 works in notation — 1d3, 2d7, 1d30 — even though the buttons cover only the standard polyhedral dice.