I found this. maybe will help?
Casino Random Number Generators Revealed
Unlocking the Mysteries of Casino RNG’s
Did you ever wonder just who – or what – decides what number will come up on an internet game of roulette? What determines whether an Ace or a 4 will be dealt out in a video poker game? How it’s decided what symbol will show up on a video slot machine? Just how it’s determined which way the dice will roll in an online craps game?
Well, first of all, it’s not a who, it’s a what. And that “what” is called a Random Number Generator, which is often abbreviated as RNG. Put very simply, an RNG is a system for generating a totally random series of numbers. “Random”?
Yes: Random, unconnected, unpredictable, lacking any pattern. The number that just was generated in no way controls or influences the number or numbers that follow. The fact that the last number generated was a 6 does not preclude the next number from being a 6 again, nor does it in any way predict what number is going to follow next, or even what number is likely to follow next.
This is useful not only in online casinos but also in statistical work and in cryptography, and in some security applications. But what is a random number generator? How does it work – and is it similar to a poker room RNG?
It can be a mathematical formula that can be worked out on paper (albeit laboriously), or it can be (and these days much more often is) a computer program. While some computer programs fall short of total randomness (although coming close, with no discernible patterns), others are the 100% genuine article.
Even in the ancient days, something of a rudimentary random number generator existed: People drew cards or tossed dice to pick a number or series of numbers from 1 to 10 or 1 to 6 at random. Today, computers use algorithms (sets of specific rules) to generate long or infinite sets of unrelated and unpredictable numbers. More common than true RNGs are PRNGs, or pseudo-random number generators. These algorithms can create runs as long as millions of numbers that are genuinely random, but after that the sequence repeats itself, or the memory usage involved becomes more than the computer can handle.
Many PRNGs, however, while unsuited to cryptography, security applications, or perhaps to statistical work, are quite adequate for casino work, non-casino video games, and other such applications. Many RNGs and PRNGs require the user to specify an initial value. This is called a “seed.” If you initialize the RNG/PRNG with same seed twice in a row, you will get the same set of “random” numbers twice in a row. This can be a good thing… such as in cryptography, where both parties need to be able to replicate each other’s results. But by varying the seed, you get a completely different set of numbers. This makes the application suitable for such uses as in online casinos. Some programs use the clock time as the seed, thus obviating the need for human choice at all.
One type of random number generator actually involves several RNGs running simultaneously, with a sort of “boss” RNG picking from among the results. Let’s say there are five “lower-level” RNGs, each generating a number in tandem. And let’s say that on one round the numbers generated are 2, 5, 26, 47, and 41. The “top boss” RNG then selects— again, at random— one of these five numbers… let’s say 26. Thus there is sort of a double randomness to the calculation.
If you’ve ever wondered just how the online casinos “choose” which cards are going to come up, which roulette numbers the wheel will “spin” to, or what the fall of the dice will be, wonder no more. Like so much else these days, it’s all done with computers!
