Slot machine evolution. While contemporary video slots can have five or more reels with hundreds of paylines, traditional slot machines only had three reels and a small numbbuffalo slotser of symbols. Random Number Generators: Maintaining Equitable Results. A random number generator (RNG) determines the results of each spin, guaranteeing that they are completely random and equitable. For the game to remain fair and give every player an equal chance of winning, this randomness is essential. Knowing the Parts of a Slot Machine.