Are random number generators really random?
All fair, modern slot machines rely on a Random Number Generator (RNG) that is hardware-based and, as such, generates random numbers by sampling naturally occurring electromagnetic noise. Random numbers are not derived by means of a repeatable algorithm, or set of rules, so even if the starting point, or any other number, in a sequence is known, the sequence cannot be reproduced at a later date.
The outcome of each spin of the reels of a slot machine is determined by the RNG, which generates thousands of random numbers per second. Consequently, while the outcome may be winning or losing, depending on the exact millisecond when the reels are activated, the player cannot predict what will happen, one way or the other, and each spin is an independent, truly random event. Indeed, it is the combination of fair, random numbers and other mathematical considerations, such as the weighting of the virtual reels, pay table and so on, that provide a casino with its house edge on slot machines.
By contrast, a so-called Pseudo Random Number Generator (PRNG) is software-based and relies on mathematical algorithms to mimic randomness based on a 32-bit integer, known as a ‘seed value’. However, PNRG algorithms can be reverse-engineered, such that the exact sequence of pseudo-random numbers for each seed value can be predicted. In the past, this vulnerability has been exploited by unscrupulous individuals, who have illicitly profited by hundreds of thousands, or millions, of pounds from slot machines at casinos worldwide. Consequently, the PNRG is a thing of the past as far as slot machines are concerned.