Modern gaming machines use computer technology to operate their functions. Slot machine outcomes are determined unsing a Random Number Generator (RNG) which is a mathematically-based program that selects groups of numbers to determine which symbols are selected to produce a winning or losing outcome.
While the results in slots are random and determined by a random number generator (RNG) within the game, there are some fixed parameters that determine the chance of winning. For example, the number of symbols for each type is fixed. More matching symbols on the reels can result in more frequent wins.