How Slot Machines Work

Almost all slot machines used in casinos today are controlled by microprocessors. This means the machines can be programmed and are more like computers than mechanical boxes composed of gears and wheels. During the evolution of the modern slot machine, manufacturers took a whack at eliminating the traditional spinning reels in favor of a video display, and replacing the pull handle with a button. The public rejected these innovations, however, and the spinning reels in favor of a video display, and replacing the pull handle with a button. The public rejected these innovations, however, and the spinning reels and pull handles have been retained. In a modern slot machine there is a device that computer people call a "random number generator" and that we refer to as a "black box." What the black box does is spit out hundreds of numbers each second, selected randomly, in no predetermined sequence. The black box has about four billion different numbers to choose from, so it's very unusual but no impossible for the same number to come up twice in a short time.

The numbers the black box selects are programmed to trigger a certain set of symbols on the display, determining where the reels stop. What most players don't realize, however, is that the black box pumps out numbers continuously, regardless of whether the machine is being played or not. If you are playing a machine, the black box will call up hundreds or thousands of numbers in the few seconds between plays while you sip your drink, put some money in the slot, and pull the handle.

Why is this important? Try this scenario: Mary has played the same quarter machine for two hours, pumping an untold amount of money into it. While she turns for a moment to buy gum from a cigarette girl, a man walks up to Mary's machine and wins the grand jackpot. Mary is livid. "That's my jackpot," she screams. Not so. While Mary bought her gum, thousands of numbers and possible symbol combinations were generated by the black box. The only way Mary could have won the grand jackpot even if the man had not come along would have been to activate the machine at that same exact moment in time, right down to a fraction of a millisecond.

There is no such thing as a machine that is "overdue to hit." Each spin of the reels on a slot machine is an independent event, just like flipping a coin. The only way to hit a jackpot is to activate the machine at the exact moment that the black box randomly coughs up a winning number. If you play a slot machine as fast as you can, jamming in coins and pumping the handle like a maniac, the black box will still spew out more numbers and possible jackpots between each try than you will have pulls in a whole day of playing.