While some casino games have a skill element in the outcome, some casino games are purely based on chance. Because all online casino games are partly or completely driven by chance, relevant web-site all casino games depend upon a random number generator, or RNG within the software that powers the game. The RNG is a mathematical application that does exactly what it says: generates a totally random number. Not all RNGs are identical, and they have to be tested extensively to ensure that the numbers they generate actually are random.

In certain games, the utilization of an RNG has an obvious role. In European roulette, for example, the RNG generates a number from 1 to 37 (with 37 corresponding to "0") on the roulette wheel. The RNG generates a number, the casino stops, and bets are paid or forfeited.