Roll dice notation such as 2d6+3, 4d6kh3 or d20 advantage, and see the exact chance of every total and of beating a target number.
To roll dice for D&D, type the roll in dice notation: 2d6+3 means roll two six-sided dice and add 3. The number before the d is how many dice, the number after is how many sides, and +3 or -2 is a fixed modifier. A d alone means one die, so d20 is one twenty-sided die, and d% is a percentile die, the same as d100. Put one roll on each line, up to 20 lines, and every line is rolled each time you press Roll. A term can hold 1 to 100 dice of 2 to 1000 sides, a line can hold 200 dice and 10 terms, and a line can mix dice and numbers, such as 2d6+d4-1. Your browser's secure random source, when available, rolls every die, so each face is equally likely.
Add kh and a number to keep the highest dice, or kl to keep the lowest, so 4d6kh3 rolls four dice and keeps the three highest. This is the usual way to roll an ability score. Drop notation works too: 4d6d1, 4d6dl1 and 4d6kh3 are the same roll, and dh drops the highest. Advantage rolls two d20 and keeps the higher one, and disadvantage keeps the lower one. Type adv or dis at the end of a line, as in d20+5 adv, or choose Advantage or Disadvantage in the setting, which rewrites only lines that hold exactly one plain d20; every other line is rolled as written. The page rewrites a plain d20 as 2d20kh1 or 2d20kl1, so you can see exactly what was rolled. It needs exactly one plain d20 in the line: d20+d20 adv is refused with a message. Rolls where the kept d20 shows 20 or 1 are marked natural 20 or natural 1.
The odds are calculated, not simulated, so they are exact. For the first valid line the page shows the lowest and highest total, the average, the standard deviation, the median, the most likely total, and a table with the chance of each total and of that total or more. A d20+5 against a target number of 15 needs 10 or more on the die: 11 faces out of 20, so 55%. With advantage the chance is 1 minus 0.45 times 0.45, which is 79.75%, and with disadvantage it is 0.55 times 0.55, which is 30.25%. 2d6+3 reaches 10 or more in 21 of 36 ways, or 58.33%. 4d6kh3 averages 12.24, with a lowest total of 3 and a highest of 18, and reaches 15 or more in 300 of 1296 ways, or 23.15%. Lines after the first get a one-line summary of their average and range.
There are no exploding dice, rerolls, success counting or Fate dice, and multiplication and division are not read. Exact odds are skipped when the work would be too large, for example 100d100kh50, and the table is skipped when a line has more than 200 different totals, such as 100d6, though the summary figures stay exact. The page does not keep a character sheet or sync rolls between devices, and the history of the last 10 results exists only until you reload. For a quick roll of a few plain dice shown as pictures, with no notation, use the dice roller at /dice-roller. Other tabletop rules, such as which die a spell needs, are for your rulebook.
Type 4d6kh3, or 4d6d1, on a line and press Roll. The page rolls four six-sided dice, shows the lowest in brackets and adds the other three. The result runs from 3 to 18 and averages 12.24, which is why many tables roll ability scores this way.
Type d20+5 adv, or choose Advantage in the setting. The page rolls two d20, keeps the higher and adds 5. With a total needed of 15 or more, that is 79.75% against 55% for a single roll.
It is a percentile die, rolled as one d100 with results from 1 to 100. The page shows it as d100. A 100-sided roll is a single number here, not two ten-sided dice, so 00 and 100 are not separate results.
Yes. Put one roll on each line, up to 20 lines, such as d20+7 on the first and 2d6+4 on the second. The first line is the big result with its odds, and every line is listed in the All rolls box with its dice.
By counting every outcome of the dice, not by simulating rolls. 3d6 makes 10 in 27 of 216 ways, which is 12.5%. Keep and drop rolls are counted the same way, so 2d20 keeping the higher makes a 20 in 39 of 400 ways, or 9.75%.
No. Dice are rolled in your browser, in this tab, and no server receives your rolls. Your advantage and target number settings are saved in this browser; the dice text and the history are not. Google Analytics counts visits and copy presses, never rolls.