dice for RPG and tabletop games
Tabletop RPG systems describe any roll with the NdX notation, where N is the number of dice and X the number of sides, and understanding that notation is the first step to predicting what a roll tends to produce before the dice even land.
A classic ability-score-generation roll: the 10.5 average is the statistical center, but 10 and 11 come up in 27 of the 216 combinations each, far more than the 3 or 18 extremes.
The +2 modifier shifts the whole curve without changing its shape: the range moves up 2 points on each end, and the average rises from 10.5 to 12.5.
Keeping the higher of two dice does not change the minimum (1) or maximum (20), but it pushes the average almost 3.3 points above a single d20, because low values become rarer to survive both dice.
Yes. Each face is selected with `crypto.getRandomValues()`, which uses the operating system's cryptographically secure generator, with value rejection to avoid modulo bias. Every value has identical probability.
It means rolling 4 six-sided dice and dropping the lowest value, then summing the remaining 3; it is the common ability-score-generation method in D&D, and it shifts the average to about 12.24 (versus 10.5 for a plain 3d6), because the worst of the four dice is removed before the sum.
Because there are far more three-dice combinations that sum to 10 or 11 (27 each, out of 216 total) than combinations that hit the extremes: there is only one way to roll a 3 (1-1-1) and one way to roll an 18 (6-6-6).
It is shorthand for `d100`, a percentile die from 1 to 100, used in random-event tables and percentile systems like Call of Cthulhu; this tool converts `d%` to `d100` automatically.
No. Advantage means rolling 2d20 and keeping only the higher value (`kh1`), not adding both together; summing two d20s would give a range of 2 to 40 with a 21 average, a completely different result from the actual mechanic, which keeps the 1-to-20 range.
1d6 · Min 1 · Max 6 · Avg 3.5
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