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What Makes Slot Machines Work?


Thousands of slot games populate casino floors and the internet, with new ones dreamed up all the time. They may come in dazzling shapes and themes, but all of them have the same underlying technology. It’s a good idea for players to understand what makes slot work so that they can make informed choices about which machines to play.

A slot is a narrow notch or groove, as in a keyway in machinery, a slit for coins in a vending machine, etc. It may also refer to a position in a group, series, sequence, or hierarchy. The term can be applied to human activities as well, such as a person’s social class or position on an employment ladder.

Modern slot machines are designed with microprocessors that program them to assign a different probability to each symbol on each reel. This is why it sometimes seems that a particular symbol is so close to hitting, or that a certain reel keeps spinning and never produces a winning combination. The truth is that the microprocessor’s random number generator (RNG) has already selected all the possible stops on the visible reel, so it only displays them to the player as a courtesy.

In addition to the number of symbols, slot machines are also programmed to weight their appearance on each reel. Lower paying symbols, for example, will have a higher frequency than the jackpot symbols. This means that they appear (along with blanks) more often, and that the odds of hitting a jackpot symbol on a given spin are much less than you might imagine.

While it might not feel like it at the time, slots are rigged to make money for casinos. If they didn’t, players would stop playing and the casinos would go out of business. Most jurisdictions require that slots return a minimum percentage of the money put into them, usually 85 percent. But even that small amount is not enough to make most people happy, and casinos must rely on the hope of big wins to keep their players coming back.

As a result, the houses edge on most slot games is between 4 and 8 percent. Those are not insignificant numbers, especially for players who have long-term experiences with the machines. Psychologists Robert Breen and Marc Zimmerman have found that video slot players reach debilitating levels of gambling addiction three times more quickly than do those who play traditional casino games. The 60 Minutes report of 2011 “Slot Machines: The Big Gamble” emphasized the role that these devices play in the development of addictive behaviors. Despite this, many players are unaware of the risk factors and don’t take steps to limit their play. Whether they are playing online or at a live casino, players should always know the risks and set limits for themselves. They should also try to diversify their experience, by trying new games from unfamiliar game makers. This will help them avoid getting bored with one type of machine and give them more chances to win.