Dice Roller
Roll custom dice (d4, d6, d8, d10, d12, d20, d100) with modifiers for tabletop RPG games.
Roll Output
What random dice actually look like
A fair six-sided die gives each face a 1/6 probability, and each roll is independent— the die has no memory. Five sixes in a row does not make a sixth less likely, and the belief that it does is the gambler's fallacy. The probability of any specific sequence is the same as any other; only our expectation of what randomness should look like differs.
Summing dice changes the shape entirely. One die is uniform, with every result equally likely. Two dice are not: 7 comes up six times more often than 2, because six combinations produce it and only one produces a 2. Add more dice and the distribution converges on a bell curve, which is why 3d6 clusters heavily around 10-11 while a single d20 is flat — the reason tabletop systems choose one or the other deliberately.
Expected value is the average over many rolls: 3.5 for a d6, and n × 3.5 forn dice. Digital rollers use pseudo-random generators, which are deterministic sequences from a seed — fine for games, unsuitable for anything requiring unpredictability. A naive modulus on a random integer also introduces modulo bias unless the range divides evenly, making low faces marginally more likely.
Frequently asked questions
How does virtual dice rolling work?
Virtual dice rolling uses crypto-grade random number generation to produce fair random integers between 1 and the die size.
Are the rolls actually random?
They use the browser's built-in pseudo-random generator, which is statistically uniform and perfectly adequate for games but is not cryptographically secure - it should never be used where an adversary could benefit from predicting the output. For tabletop play the distribution is indistinguishable from physical dice, and arguably fairer than a cheap unbalanced die.
What are the odds on two six-sided dice?
Sums are not uniform: 7 is the most likely at 6 chances in 36, while 2 and 12 each have 1 in 36. That triangular distribution is why 7 is central to craps and why 2d6 games feel different from a single d12 with the same range.
What does notation like 3d6+2 mean?
Roll three six-sided dice, add them together, then add 2. The pattern is NdX+M: N is how many dice, X is the number of sides, M is a flat modifier. Rolling multiple dice clusters results toward the average, which is why 3d6 produces far fewer extreme values than 1d18 would.