The modern slot machine uses an algorithm known as a random number generator, RNG, which does not use any form of memory to determine when a number should be generated.
Although it is known as a random number generator, the modern, Online slot machine actually randomly generates the different tiles used on the different spaces of a slot machine. All the different combinations of numbers, whether generated across three, five, or even greater numbers of reels, are random and must generate numbers independent of each other.
The history of slot machines began with metal reels filled with numbers that would spin and stop with a magnetic braking system. This system would randomly generate a stopping point for each drum after the reels were spun by the player. Some players would believe they had seen a moment when a slot machine became hot or would stop paying out.
RNG is used in video slots in casinos around the world. The modern slot machine does not have any built-in memory and generates hundreds of numbers per minute.
The lack of memory means the algorithm used to generate each number is completely independent of each reel on the slot machine. It is possible for a player to hit a jackpot on a number of occasions in specific plays, but this is a purely random part of the gameplay developed through the use of algorithms.
Every slot machine at a casino uses something called a par sheet which provides information about the odds for each tile on a reel. Each reel is weighted to reach a certain number of spins for every time a certain tile is generated by the algorithm. The lower the number of tiles appearing on each reel lowers the odds of a jackpot.
Each slot machine algorithm also includes the payback percentage which gives an insight into the winnings a player can expect as they play. The percentage is usually given as a number of around 97 percent which means a player can expect to win from $3 gambled in every $100. This number is not a figure of how much money a player will win but is part of the algorithm deciding how often the slot machine will offer a winning spin.
Want to know where slot machines came from? Check out the history here!