Most players at least know the basics of a slot machine – drop in a few bucks, hit the spin button, watch the reels spin around and around before coming to a stop, and then see if some winnings are heading your way. But there are some other aspects of slots that the average player may not realize.

Some of these secrets of the slot machine world can offer some insights into the technology behind today’s machines, the history behind those “one-armed bandits”, and the symbols and lore involved with these immensely popular games.

Keep reading for some of those interesting trivia and slot machine secrets exposed:

Fruits, Bells, & Bars

A quick look at slot machines and one will find some symbols that are found frequently in numerous games, such as fruit, bells, bars, and playing card symbols. While many modern games feature unique symbols, this traditional group dates back to the game’s early days including to the original inventor, Charles Fey.

Fey’s original machine from the late 1800s included bells, hearts, diamonds, spades, and horseshoes. Fruit symbols were added in the early 1900s. The bars came from another earlier machine and are believed to have originally been sticks of gum that transitioned to bars when slots began paying in cash instead of chewing gum.

Symbols Are Only ‘Symbolic’

Most slot fans look for just the right symbols to show up for that jackpot. But algorithms and the number generator within the machine determine whether a player is a winner or not, with the symbols simply showing a representation of that result.

“A slot machine algorithm is heavily dependent on what is called an RNG,” notes. “RNG stands for Random Number Generator, and it’s an engine that constantly churns out random numbers, and in the case of online slot machines: random symbols on the reels.”

Online Slots Usually Are More Favorable for Players

Those who can play slots online in legal jurisdictions will find games usually with a higher RTP than often found in a live casino. This stands for “return to player” and is the total percentage of money put into a slot or casino that’s paid back out to players. Slots at live casinos generally have RTPs in the 80-90% range, but online slots often see RTPs at 95% or even higher.

You Win a Cigar

Early slot machines didn’t pay out cash. Some of the first games in the late 1800s paid out winners with prizes like a nice cigar or chewing gum. However, some bar or tavern owners might pay out in cash on the side. These prizes went away as cash became a more popular prize.

Game Show Shenanigans

In recent years, pop culture has become a much more prevalent slot machine theme. That includes game shows like Wheel of Fortune, which has become one of the most successful slot brands since debuting in 1996. Other popular game show slots to hit the casino floor include The Price Is Right, Jeopardy!, Hollywood Squares, The Match Game, Let's Make a Deal, and Deal or No Deal.

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Time Stand Still

For slot manufacturers, time spent on a device helps determine profitability. There’s a reason many games feature so many bonus games and frequent winning spins (at least to some degree). These games are designed to keep the player spinning those reels.


Casinos offer numerous opportunities to gamble, such as table games, a poker room, a sportsbook, and more. But the slot machine is the casino king when it comes to revenue. Many in the industry estimate the average casino produces about 85% of its revenue via slot machines.

The University of Nevada, Las Vegas reports:

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“With slot machines producing the bulk of profits in most of the world’s casinos, gaming managers make it their business to keep slot players happy.”

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Some Slots Aren’t Technically Slots

While a player may be spinning reels on what they think is a slot, this isn’t technically always the state. Laws vary by jurisdiction about the game and in some U.S. states, you may be playing VLTs (video lottery terminals). These games are often based on bingo or lotto, with players theoretically competing against each other.

Horsing Around

Some states also feature games called HHRs (Historical Horse Racing), also known as “instant racing.” These games may look like slots but the results are based on thousands of random past horse races instead. It’s a unique way to allow players a slot machine-like experience.

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“Historic horse racing machines date back to the late 1990s, when the idea was conceived by the general manager of Oaklawn Park race track in Hot Springs, Arkansas,” the Las Vegas Advisor notes. “The Arkansas Legislature approved them and the first HHRs were installed at Oaklawn in early 2000. Oregon and Wyoming followed suit in 2003, though they were deemed illegal in both states and didn't return for 10 years. The same sequence was repeated in Nebraska, Idaho, and Texas.”

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Slot-Like Machines Are HUGE in Japan

Slot machines and casinos have been illegal in Japan for a long time (although the government voted in 2018 to allow three casino resorts). Instead, the country is in love with slot-like games called pachinko.

Pachinko parlors are located throughout Japan and players pull a lever sending a small metal ball up to the top of the machine, bouncing around until it falls into various receptacles, some awarding more of the balls. The balls can be exchanged for cash or prizes and Business Insider reports that Japanese gamblers spend as much as $200 billion a year on Pachinko games.

A Gambling Device All in One

Slot machine inventor Charles Fey solved a unique problem that precursors to his Liberty Bell device weren’t able to – namely creating a single device that could take a bet, perform the activity wagered on, and also payout any winnings.

Before the Liberty Bell, machines paid out a ticket or a token, requiring an attendant to pay out winners. However, Fey solved that and created quite an ingenious device – the first gaming machine that didn’t require any humans to accept a bet or payout.

Ready for Rewards

Modern slot players are accustomed to sliding their reward cards into a slot machine. The accrued loyalty points can be used for merchandise, free play, meals, hotel rooms, and more. Some of the first cards appeared in the 1980s, but the programs have seen high-tech innovations in recent years. That includes allowing players to earn loyalty points in other ways and also tracking a player anywhere in a casino.

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When a guest checks in at Resorts World, I can recognize and thank them,” Resorts World Senior Vice President of casino operations Rick Hutchins told the Las Vegas Review-Journal. “When they enjoy their journey throughout the property, I can recognize them and reward them. If they leave for five hours somewhere, I can notice that they’re missing and I can do something to help bring them back.

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Casino Slot Meet Online Slot

Some players may be hesitant about online casino slots, feeling that they may be rigged or operated differently. In reality, these slots are the same game you’d play in a casino. As noted earlier, many online slots have higher RTPs than those in a live casino, making them more favorable for players.

Name Game

Slots have some interesting names depending on where you’re located. While they’re called “slot machines” (originally named for the slot to insert a coin), the same games are called “fruit machines" in the United Kingdom (named for the fruit symbols appearing on early machines).

In Australia, the games are known as “pokies” because some early machines used symbols and combinations based on poker hands. Scotland checks in with another interesting name for slot –  “piggies,” often cited named so because some cash dispensing machines in the country are also piggies, and a slot also dispenses cash as well.

Video Poker Machines Are Considered Slots

Many slot players may not realize that video poker games are considered a form of slot machines. These games, however, allow some interactivity with players deciding which poker cards to keep or draw. Both games use RNG, but a player using the perfect strategy on some games with the best rules can flip the house edge slightly in his favor.

Seven Up

The number is big in the world of casinos. That goes for craps and slot machines. In craps, that number can end a roll and usually register wins for the casino. On slots, many games feature seven as a winning number on many classic and modern machines, such as Blazing 7s.

This number represents luck and good fortune in many cultures. Some ancient people believed the seventh son of the seventh son would be gifted with magical powers. In the Bible, God created the world in six days and rested on the seventh. There are seven heavens in Islam and Judaism, seven represents harmony In Confucianism, the number represents harmony. Hindus believe in seven higher worlds and seven underworlds. Buddhists believe the newborn Buddha takes seven steps.

Cheating Chatter

The idea of winning big sums of money can be alluring to some criminal types. While finding a way to make a machine payout when it’s not supposed to, some ingenious crooks have found a way through the years. How would one go about making this happen?

Some of those cheating devices have included “light wand” electronic devices that could be inserted into the payout chute and trick the machine into dropping more coins. A “monkey paw” into the coin slot, tricking the machine into increasing the coin-in count.

More recently, a group of Russian criminals reverse-engineered a type of Aristocrat machine and used an app to communicate with cohorts in Russia and predict the games’ outcomes. Cheating doesn’t pay in the long run, however. The Russians and other cheaters have received lengthy prison sentences when caught.

In Constant Motion

Slot machines continue working even when no one is playing. The reels may continue spinning to make sure spins remain despite no one hitting the spin button. The random number generator continues working whether you’re ready to play or not.

Location, Location, Location

Most slot fans are probably accustomed to playing slots in casinos, online, or perhaps in bars, pubs, and restaurants in some states. But Nevada even allows slots in more locations that might seem a bit strange to many.

Have the urge to wager while shopping for fruit, vegetables, milk, and bread? Many grocery stores house slots for that quick urge to take a shot at a jackpot. Reno and Las Vegas are also the only airports in the U.S. that host slots, allowing eager slot fans to play a bit on arrival or drop a few bucks as they wait on their plane to head back home.

Streaming Strength

Slot machine streaming has grown in popularity with many players filming their casino play for YouTube or playing live online on Twitch. Some players, such as popular YouTuber Brian Christopher, are even making their living by playing slots online.

“A new class of niche celebrities has turned the once-solitary experience of gambling at casino slot machines into a spectator sport with millions of viewers and fan camaraderie,” the Wall STreet Journal reports. “Using monopods or videographers to film the action, the players spend hours talking audiences through the highs and lows of jackpots and losses.”


Slot machines remain the most popular games in a casino and many properties devote about two-thirds of their gaming floor to slots. These devices are fairly new when it comes to the history of gambling, but have surged in popularity as the industry has embraced technology over the last couple of decades.

Modern games offer players advanced software and hardware, interesting themes, complex narratives, fun bonus features, and so much more. Let us know your thoughts on these games and some of your favorite games and features.