" Dice rolls on Roll20 are processed by QuantumRoll to provide true randomness in each roll. The engine itself is powered by a powerful, thoroughly-tested RNG, seeded by an entropy source deriving from quantum fluctuations ." This is not strictly correct. There is not true randomness with each roll. There's still a PRNG (pseudo random number generator) in there (the "powerful, thorughly-tested RNG"). The seed is truly random, assuming that the entropy generator isn't fooling itself. In between re-seeding, though, the sequence of numbers is deterministic. Practically speaking, this is not important. PRNGs, at least if the algorithm is good, are great, and have all the statistical properties you'd want of a random number. They're used all the time in scientific simulations. For gaming , their statistical properties are almost certainly way better than dice you roll at the table. (They're not great for the hardest core cryptography, but that's not at all what we're doing.) I have seen people on gaming forums say "never use computer dice
rollers, they're not truly random." That's a complete red herring.
Yeah, somebody could hack them to cheat. But, if the players are using
them fairly, the computer dice rollers are almost certainly better than
dice. So, I'm not quibbling that there's anything wrong with the algorithm, but I am quibbling with the fine details of how it's represented. (Assuming that there's just one RNG that everybody pulls from, it's even better than that. Even if you roll two d20s right in a row, chances are that some number of people have rolled them in between. So, you're not even getting the numbers in sequence, but there's some sorta-random gap between the numbers you get yourself.) There is of course one wrinkle. The PRNG has to be a decent one. There's a notorious PRNG named RANDU that was discovered long after the fact to have bad statistical properties that weren't obvious to casual inspection. But, the ones folk use nowadays are, as the "QuantumRoll Status" says, generally thoroughly vetted and tested. My first question: Which PRNG algorithm is in use? It's nominally a thoroughly tested one, but which one? Second, the QuantumRoll Wiki page says "QuantumRoll introduces a new site-wide "status dashboard" showing all the rolls being made in Roll20 games for the last hour". However, I have not been able to find the list of all the rolls on the statistics page linked , just the number for each value on a d20 and the average number. My second question: What am I missing? Where can I find the list of all rolls? (Why does it matter? The aforementioned RANDU would have done just fine on a histogram of all die results. The problem wasn't that the dice were "weighted", so that some numbers would come up more often than others over a long period of time. The problem rather came into correlations and patterns of how the numbers would show up. If one really wants to vet the generator independently, one needs the raw data, or, equivalently, the algorithm in use.)
