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Some of the blog posts I’m most proud of here are the ones in my “ultimate guides” series. So far I’ve written ultimate guides to United States lottery games, greyhound racing, and Atlantic City casinos.

Today, though, I’m writing about something even bigger—the king of casino gambling games.

Today’s post is the ultimate guide to slots and slot machines.

My goal with this post is to share everything you might need to know to play slot machines intelligently in a casino.

Here are the topics covered in this post:

• The history of these games
• Differences in gameplay from one country to another
• How to play slots in Atlantic City, Las Vegas, Reno, or anywhere else
• How the payback percentage, probability and odds work
• Which different kinds of games are available
• The most popular games
• How slot machine tournaments work
• Which of those games are best for the discerning gambler?
• Questions and answers

The History of Slot Machines

If you’ve read anything about antique slot machines or about the invention of these games, you’ve heard of Charles Fey. He was a mechanic living in San Francisco. In 1887, he invented a game with 3 spinning reels. Each of these reels had 5 symbols on them:

• Diamonds
• Hearts
• Horseshoes
• Liberty Bell
• Spades

The Liberty Bell

You’ll notice a playing card theme here, but you’ll also notice horseshoes—symbols of good luck. And the Liberty Bell is the symbol from which this prototypical slot machine game gets its name. The game originally required an attendant to pay off wins, but he continued working on and improving the machines. Eventually (by 1898), you could play a Liberty Bell slot machine and win a whopping 50 cents from the machine directly.

A Tradition of Outsmarting the Law

The games were quickly made illegal because of their gambling nature. But entrepreneurs are creative, and Fey (and other imitators) got around these restrictions by paying off winnings in candy. This is where we get the ubiquitous fruit and bar symbols seen still on these games today. The fruit symbols used to represent the flavor of the candy won. The bar symbols represented sticks of chewing gum.

In some ways, history keeps repeating itself. I live in Texas, and you’ll find slot machines called “8-liners” throughout the state. I’ve seen them in bars, in gas stations, and in “game rooms”. Since slot machines are (strictly speaking) illegal in Texas, these games don’t pay off in cash.

Instead, you get points which you can use toward prizes. I spent some time in a game room in a small town in Texas where you could literally cash in these points for canned goods like corn. They also had a cheap set of gardening tools available.

I’ve also played 8-liners in bars where if you won you had to visit the owner of the bar on Friday to pick up “an envelope”. This envelope had your cash winnings in it. But God forbid you ask for an envelope if the owner didn’t know who you were.

These are just examples from my personal experience of clever entrepreneurs skirting anti-gambling laws to continue to offer slot machine games to their customers. In that respect, things have changed little since the 1890s.

In fact, these gambling machines changed very little for decades, although they did become fixtures in the casinos. For years, these games were considered a distraction for the wives of the “real” gamblers—the men who were playing blackjack, craps, and poker. They were found in the places in the casino where the management thought they’d be more likely to attract the attention of these women.

Bally Technologies, Money Honey, and New Electro-Mechanical Games

Things started to change in the industry in the 1960s with the introduction of the first electro-mechanical slot machines. Bally Technologies invented a game called Money Honey, which incorporated a combination of electronic components. These gizmos enabled the designers to accept multi-coin bets. These games also ran faster.

Faster games with higher payouts increased the popularity of such machines, but they didn’t take over the casino floors immediately. This has been a gradual process that hasn’t stopped. But the invention of electro-mechanical machines like Money Honey was the first step in that direction.

Video Slots Like Fortune Coin and Megabucks Change Everything

The industry took off with the invention of video slots in 1979. The importance of the developments made in the 1980s can’t be overstated. The first of these was called Fortune Coin, and it was soon acquired by IGT, the largest manufacturer of casino games in the world. Believe it or not, it was initially distrusted by gamblers. They assumed that a game powered by computer animation would inevitably be rigged and impossible to win.

By 1986, these computerized games made it possible to link multiple games to the same ever-increasing jackpot. These games are now called progressive slots, and the first—and still most famous—example of these games is called MegaBucks. The jackpot for this network of games regularly surpasses $10 million.

These larger jackpots became available because of the lack of restrictions on number of symbols on each reel. With a mechanical slot machine, you’re limited to probably 20 symbols per reel max. And since such a game is mechanical, it’s hard to adjust the probability of a symbol coming up. Each stop had an equal chance of happening.

But with a computerized game, you can program one symbol to come up once every 20 spins and another to come up once every 40 spins. The games now use PARs sheets to delineate those probabilities. The designers and the casinos know what the odds are on these games. The public doesn’t have access to this information, though.

Over the last 30-40 years, slot machines have become the most popular game in the casino. Just a decade ago, you’d often see the following factoid on the Internet:

65%-70% of a casino’s revenue comes from the gambling machines.

But that’s changed. I read a book recently which claimed that in most casinos, slots make up 80% or more of that casino’s revenue.

This is a seismic shift in gambling practices in a casino.

The Internet Changes Everything Again

In the 1990s, the Internet became a thing. It didn’t take long for gambling entrepreneurs to realize that you could use similar computer technology to offer the same kinds of games over the Internet. The Web also allowed these operators to offer their games to players in areas where gambling was illegal. (Remember—that’s a tradition in the industry.)

The thinking is that an offshore casino is regulated by the laws where it’s located. If gambling on the Web is legal in Costa Rica, for example, it’s legal for someone in Texas to gamble online there. Their contention is that the wagering is taking place where the server in Costa Rica is.

The federal government in the United States takes a less enlightened stance on this idea. They’ve made it clear that offshore companies offering gambling games to United States players are breaking the law. They’re less close-minded about whether the players are breaking the laws.

The Future

As Criswell points out in the great Ed Wood movie Plan 9 from Outer Space, we’re all interested in the future, because that’s where we’re going to spend the rest of our lives. But who knows what the future holds for slot machine gambling?

It’s clear to me that we’ll continue to see innovations which make these games even more compelling and addictive. The legal climate in the United States seems to be trending toward legalization. Just in my own lifetime, I’ve seen gambling become something that people had to fly to Nevada or to New Jersey to do. Now I can just drive an hour north to the Winstar Casino to spin the reels and try my luck.

Slot machines are going to continue to become more interactive and profitable for the casinos. Eventually, I’m going to predict that they’ll become too interactive and addictive. At that point, the government might start restricting gambling on a legal basis again. The pendulum seems to swing back and forth with such things, at least in the USA.

Most of the research for this section was done using Wikipedia.

How to Play Slot Machines at Casinos in Atlantic City, Las Vegas, Reno, or Anywhere Else

Slot machines are the easiest games in the casino to play.

You insert money, push a button or pull a lever, watch the spinning reels, listen to the sounds, and collect your winnings (if any).

In fact, slots are so simple to play that it almost seems silly to write a guide on the subject.

But like any other gambling activity, playing slots has subtleties that aren’t apparent.

In practical terms, here’s what you need to know about playing these games.

When you’re looking at one of these games, you’ll notice that it looks a lot like a traditional coin-operated video game in an arcade. Only most slot machines have a lever on the side.

And in fact, most modern slots have more in common with video games than anything else. 50 years ago slot machines were mechanical and powered by springs and gears, but modern slots are powered by computer programs and video screens.

When you’re facing the machine, you’ll see the name of the game and its logo at the top. Underneath that are the spinning reels that make up the game. On many modern games, these spinning reels are animated.

If it’s an old-school machine with actual physical spinning reels, a pay table will be printed on the glass above or to the side of the spinning reels. This pay table shows the possible winning combinations of symbols and how much they pay if you hit them.

On newer machines with animation, you can access the pay table via the controls on the screen. (The controls and the pay table are both part of the animation, usually, although some machines have physical controls on the console.)

Most slot machine games still have a lever on the side, but it’s just for show. When slot machines were purely mechanical affairs, you’d use the lever to start the reels spinning. Now you have the option of pushing a button on the console to start the reels spinning. There’s no advantage to using either option, although you’ll play slower if you use the lever instead of the button.

Beneath the spinning reels is where you put your money into the machine. Some modern machines only have bill changers, but some still also accept change in a coin slot. When you input your money, the machine updates electronically and displays how many credits you have.

Beneath where you input the money is a metal tray called a hopper. In the old days, this is where your winnings would spill out. They were paid in coins, and casinos used to have big plastic buckets located throughout to use to put your coins in.

Most modern slot machines use a ticket in/ticket out system now. You cash these tickets in at the cage in the cashier area, just like you would cash in clay casino chips. The bill changer on modern slots will also read your tickets—you can insert them just like cash.

The ticket in/ticket out system has a lot of advantages for the casinos, the biggest being breakage. That’s just a fancy word to describe tickets that don’t get claimed. Many gamblers don’t want to waste time standing in line at the cage to cash in a ticket that might only be worth a couple bucks.

The casino gets to keep this money if the players don’t claim it.

And a couple of bucks per person matters a lot when you’re dealing with thousands of people per day.

The actual mechanics of playing are simple, though. You insert your money, choose how much you want to wager per spin, and wait to see what your results are. When you’re ready to cash out, you push the button to cash out and take your ticket.

Some games do pay more if you play max coins, but others don’t. Read the pay table to find out beforehand. If the game has higher jackpots for playing max coins, you’ll probably want to do so. If you can’t afford to, you should move to a lower denomination machine.

These games are played in the same way regardless of where the casino is. Slots in Las Vegas play just like the games in Atlantic City. The games in Reno are the same, too. The insides might work differently from one locale to another, but that difference is more-or-less opaque to the player. I’ll write more about the different kinds of innards slots have in the next section.

I referred frequently to this article when I researched this section.

World Slot Machines

These games aren’t just played in the United States. They’re popular in other countries, too. In fact, in some countries (ahem, Australia), they’re practically a national pastime.

But most countries call them by another name.

In England, they’re called “fruit machines”.

In Australia, they’re called “pokies” (short for “poker machines”).

In Norway, they’re called “kronespill”.

In Scotland, they’re called “puggys”.

In Canada (and often in the U.S.) they’re called “slots”.

They all feature spinning reels. That is, in fact, the defining aspect of such a game.

But they also feature different gameplay options and variations depending on where you live.

Fruit machines, for example, differ slightly from regular slot machines. In fact, they resemble the 8-liners found in bars in Texas. They resemble video poker machines, in a sense. That’s because they almost always give you the option to hold some symbols and take another spin on some of the reels. This doesn’t imply that skill helps in any way. The results are still randomly controlled by a random number generator, and no amount of so-called strategy will improve your odds.

Pokies, on the other hand, usually feature a massive number of pay-lines and lots of bonus features like scatters, wild symbols, and bonus games. The newest innovation in pokies are the games with 243 ways or 512 ways to win. These basically eliminate the concept of pay-lines entirely. Any winning combination from left to right results in a win.

I should point out to that one of the biggest and most popular gambling destinations in the world now is Macau. But slot machines aren’t a big draw there. In fact, baccarat occupies the position in the casinos there that slots hold here in the U.S. Over 80% of a Macau’s casino revenue is generated from baccarat, not slots. That’s a significant cultural difference, to be sure.

I consulted this page when researching this section of the post.

Slot Machine Games and Variations

The original slot machines developed at the turn of the last century were mechanical devices with actual metal reels inside them. When you pulled the lever, the springs set those reels to spinning. Symbols were printed on the front of the reels, and when they lined up, you got paid off.

For example, you might put a penny into such a machine, pull the lever, and see three cherries line up across the center of the reels. That line across the center of the reels is called a pay line.

Modern slot machines often have multiple lines, but you pay to activate each line. Old-school games had only three reels and one payline.

These kinds of games still exist, but they’re no longer powered by springs and reel stops. Their results are determined by a computer program called a random number generator. These are called classic slots. They might seem boring compared to some of the newer, flashier, and glitzier games.

But they usually offer the best odds in the casino (at least as far as slot machines go).

Newer slot machines also often feature five reels instead of three. To accomplish all these extra reels and pay lines, the slot machine manufacturers use animation and computer programs. Five reel slots and multi-line slots are usually video slots. That just refers to what the game looks like.

These games often include all kinds of bonus features and games. Some of these bonus games even have skill elements. Others are completely random.

A good example of a game with a bonus feature is Wheel of Fortune slots. If you’ve spent any time in an American casino, you’ve seen and heard this game. It’s based on the popular game show. If you get certain combinations of symbols on the screen, you get to spin the wheel.

On most Wheel of Fortune games, the wheel is smaller and is located on top of the machine. I’ve seen versions that are huge and allow multiple people to sit around the wheel itself. Most players love getting to spin the wheel.

And of course, you get a bonus payout based on where the wheel lands.

These games often also include wild symbols. If you play poker, you’re probably familiar with the concept of a wild card. It’s just a card that can substitute for a card that would make a winning hand.

A wild symbol on a slot machine game works in the same way. It substitutes for a reel symbol that you would need to have to achieve a winning combination.

Modern slots also often include scatter symbols. These are symbols which don’t need to be on any specific pay line to achieve a winning combination. No matter where they appear on the screen, if the right number and type of scatter symbols show up, you get paid off.

Slot machines differ from most other gambling games. You can easily list the number of poker variations or blackjack variations on a single page. But slots come in a staggering array. That’s because dozens of manufacturers create new games constantly.

In fact, you can find several ways to categorize these games. Below are some of these ways:

Legally, slot machines can be categorized by how their algorithms work. These categorizations are Class II and Class III. They matter because they affect which kinds of games the casino can legally offer. In states which allow tribal casinos, the restriction is often that they can only offer Class II slot machines. These games are based on a bingo algorithm. All the games are networked together with a central computer which is constantly running bingo games. The payouts are based on the bingo results, and the spinning reels are just for show. Class III slot machines, on the other hand, have individual random number generators inside each machine.

Progressive slot machines have jackpots that grow constantly while you play. You’ll see a jackpot ticker at the top of such a machine which tells you what the top jackpot is. Flat top slot machines, on the other hand, have a fixed top jackpot.

Traditional slot machines have 3 reels and usually 1-3 pay-lines. These games look mechanical, even though the results are still powered by a computer program called a random number generator. Video slot machines usually have 5 reels (or more) and at least 5 pay-lines. They cost more to play because you pay to activate each pay-line. But you have more opportunities to get at least small wins.

Video slot machines are usually the games with all the bonus features like bonus games, scatter symbols, and wild symbols. All these bells and whistles result in lower payout percentages for the player, though. You have a choice. Play the fancier, more fun game. Or play the more boring game which provides you a better chance to win.

I leave it to you to decide which of those options is better for you.

I used several pages to research this section, including this one and this one. You’ll also find a page with a more comprehensive treatment of this subject right here on this site.

The Most Popular Slots Games

I read a book about gambling once that compared the popularity of slot machines with a quote from the Beatles. At one point, they claimed to be more popular than Jesus.

And if slots are that popular, specific games occupy high positions of popularity within the category. This section of the post looks at the most popular games and how they got there.

Wheel of Fortune slots are the undisputed kings of the gambling machine sections of casinos in the United States. I read a book about slots recently that claimed that IGT, the game’s manufacturer, were so eager to duplicate this game’s success that they surveyed the players to find out why it was so popular.

They got a variety of answer, of course. But one answer was common.

Most of the people who loved Wheel of Fortune slots said that the game reminded them of watching the game show on TV with their grandmother when they were young.

How can you beat that as a formula for success?

In fact, Wheel of Fortune isn’t just a single slot machine game anymore. It’s a brand. Lots of different games use the branding, and each of them has different gameplay features. They all have two things in common, though:

• The sights and sounds related to the game show.
• The spinning wheel bonus game.

Wheel of Fortune isn’t the only game to borrow elements from a popular game show. You’ll find plenty of them scattered throughout the casinos: The Price Is Right, Jeopardy, The $20,000 Pyramid, Deal or No Deal, and Who Wants to Be a Millionaire have all spawned slot machine games.

The Simpsons slots are like that, too. It’s more about branding than specific gameplay features. Multiple slot machine games share the branding, sound effects, characters, and iconography. The newest version is a big flashy monstrosity of a game. The TV show has been on the air for over 27 years now.

Notice a trend yet? Tapping into existing intellectual properties and brands is a smart move for game manufacturers and casinos. People love familiarity. You’ll find that most of the most popular gaming machines tap into this tendency.

And The Simpsons isn’t the only cartoon to spawn its own gambling game. The Pink Panther has been popular for years. South Park slots are also hugely popular. At one time, using a cartoon as the basis for one of these games was controversial. The regulators felt like this was a means of enticing under-age gamblers. But most modern cartoons aren’t even aimed at children.

Elvis slots are a big deal, too. Like the other games I’ve listed, several different machines share this branding. You can find slot machine games featuring skinny Elvis, fat Elvis, and Elvis singing different songs. (“Burning Love” is a favorite.)

He’s probably the most iconic singer to have a popular slot machine game, but other singers are in on the action, too. Dolly Parton slots are popular. Cher has her own slot machine, too. You can even find slots based on Hee-Haw, a country western music themed variety show that was on the air for decades.

In short, anything that summons nostalgia among the right demographic is a potential theme for a popular gambling machine. The more popular the brand and intellectual property, the more popular the game.

Igt 5 Cent 1986 No Buttons Slot Machine Volume Controls

Slot Machine Tournaments and How They Work

A slot machine tournament is an opportunity for you to compete against other gamblers. It’s also an opportunity to get a good little bit of action without spending a lot of money.

Here’s how most slot machine tournaments work:

You pay an entry fee. For that, you get a certain number of credits on a slot machine. The other players do likewise.

When the tournament starts, the casino sets a timer, and you get to make as many spins as possible before one of the following happens:

• You run out of credits.
• The timer runs out.

When the timer runs out, the player with the most credits is the winner.

Usually this gives you an opportunity to get a large payout for a low buy-in. Many of these tournaments are offered as freerolls by the casino to attract new customers.

I researched some of the information for this section using this page.

Probability and Slot Machines – How the Payback Percentage Works

All casino games have this in common—they pay off less than the odds of winning. For example, if you place a bet that pays off at 10 to 1, you can bet that the odds of winning are worse than 10 to 1. The casinos are in business to make a profit. This mathematical edge is how they do it.

Here’s a specific example of how that might work with a simple slot machine game:

You’re playing a game with 3 reels and a single payline. Each reel has 8 symbols on it. The probability of getting a specific symbol on a specific reel is 1/8. The probability of getting that symbol on all 3 reels is 1/8 X 1/8 X 1/8, or 1/512. This means that the odds of winning are 511 to 1. If that bet pays off at 500 to 1, the casino expects to win money in the long run.

Let’s assume you’re playing for $100 per spin. You lose $51,100 on your losing spins. But you win $50,000 on your winning spin. Your loss is $1100 on the 512 spins, which means you lose an average of $2.14 per spin.

This means the casino has an edge of 2.14% on this bet, and the payback percentage (the amount they expect to pay back on every bet) is 97.86%.

Of course, modern slot machines are more complicated than this. They usually have more than 8 symbols on each reel. They might have 15 or even 20 symbols.

Igt 5 Cent 1986 No Buttons Slot Machine Volume Control Valve

And since they’re not mechanical but computerized, they can weigh the probabilities of some symbols coming up differently than others. Some symbols might come up an average of once every 40 spins, while others might come up an average of once every 10 spins.

These numbers are all determined by the designer and the PARs sheet for the game. But the casino and the manufacturer know the exact expected payback percentage for every slot machine on the floor.

In fact, in almost every case, the gamblers don’t have the information needed to calculate what the payback percentage is for a specific game.

This makes the slot machine the only game in the casino where it’s impossible for a player to know what kind of house edge he’s facing.

I used some information presented on Gamblers Bookcase when researching this section.

Which Slots Games Are Best for the Smart Player

The best slots games for the smart players are no slots games at all. These games always have a house edge that can’t be overcome. If you play any of these games long enough, you’ll lose all your money.

So some games can be considered less worse than others, though. The lower the house edge, the better. At the same time, if a game has a low payback percentage but isn’t fun, it’s probably not worth playing, either.

What’s a smart slot machine player to do?

Here are some tips about which games, in general, offer the best odds. I also offer some personal observations about how useful each tip is.

• Flat top games are better than progressive games. Unless you’re determined to win a huge life-changing jackpot, you’re better off going with the games which have a fixed top prize. (These are called flat top slot machines.) Progressive jackpots, on the other hand, offer worse odds overall, because a tiny percentage of each of your bets goes toward increasing the size of that jackpot.
• The games with the lowest jackpots probably offer better odds. This probably seems counter-intuitive. After all, if you have two slots games that cost $1 per spin to play, wouldn’t the game with the higher jackpot offer the better odds? The short answer is no. You take two factors into account when determine a gambling game’s odds: 1) the payoff and 2) the odds of winning. On a slot machine, the larger the top prize, the less likely you are to win it.
• Higher denomination games usually offer better odds than lower denomination games. The reason for this is simple. A game that you play for a nickel can be more profitable for a casino than a penny game with an even higher payback percentage. Let’s say the penny game has a payback percentage of 90%. That means the casino wins 10% (on average) of the money put through the game. At 600 spins per hour at a penny a spin, that’s $6.00 per hour in action, and 60 cents per hour in expected profit. Let’s say the nickel game has a payback percentage of 95%. That means the casino wins an average of 5% of 600 spins at 5 cents each. That’s $1.50 per hour. The nickel game offers you MUCH better odds of winning, but the casino still makes more profit per hour. The casino WANTS you to play the higher denomination machines.
• Max coin doesn’t matter so much. On some gambling machines, it makes a difference, but this isn’t carved in stone. In fact, it’s just as common that it doesn’t matter at all. This is one of the major differences between most video poker games and most slot machines. You should ALWAYS bet max coin at video poker because of the increased payout for the top jackpot. This is not true of all slots games. Check the pay table on the game you’re looking at to know for sure.

You can also find plenty of bad advice about how to choose the best slots games. Below are some examples of advice that isn’t accurate:

• If anyone tells you WHERE the highest-paying games are, just smile knowingly and ignore them. 22 years ago, Frank Scoblete published a book called Break the One-Armed Bandits. The advice he gives in that tome is to look for games on the ends of the aisles. The theory is that the casinos want to attract players to the games, so that’s where they put the loosest machines. That’s not how it works, though—at least, not in the real world. Most casinos with identical games have games with identical payback percentages. Those that don’t place their games randomly throughout the floor of the gambling machine area.
• There’s nothing you can do to improve your chances of winning. This is true in a sense, because if you play long enough, you’ll almost certainly lose. But you can choose games which offer better odds in the short term than others. For example, avoiding progressive slots in favor of flat top slots improves your chances of winning. Choosing traditional 3-reel slots with a single payline improves your chances of winning compared to choosing 5-reel slots with a dozen or more paylines.
• Games get hot or cold. The idea behind this is that a game is either due to pay out or that it’s cold and on a cycle of losing spins. This is an example of the gambler’s fallacy in action. The idea is that you can take advantage of a winning streak or a losing streak, but the reality is that every spin of the reels is an independent event. The results of previous spins have nothing to do with the result of your next spin. Yes, you will see winning and losing streaks. But you’ll only see them in retrospect. And there’s no way to predict when they’ll begin or end. There’s no way to take advantage of what’s already happened.

A lot of the details about improving your chances of winning at slots was found at Michael Bluejay’s excellent page on the subject.

Slots Questions, Answered

Per my rigorously scientific (not) research on Google and Bing, these are some of the most commonly asked questions about slots and slot machines. Lots of people seem to want to know the answers to these questions. I’ve answered them succinctly and included links to other resources that answer them in more detail.

Which slot machine strategies are winning strategies?

Okay, so this one might not be a word-for-word question many people ask, but this is the one that gets to the point most people care about. How can you win at slot machines? Is there a smart way to play?

The short answer is that none of the slot machine strategies you’ll read about online are winning strategies. Slot machines—and every other casino game, for that matter—have an unassailable house edge. Mathematically speaking, nothing you do can improve your odds of winning.

The best you can do is try to choose games with a low house edge. You’ll at least get more entertainment for your money.

But if you play long enough, no matter what strategies you use, you’ll eventually lose all your money.

You can find comprehensive information about slot machine strategy in this page on this site.

Can you play slot machines for free?

Yes, you can play slot machines for free, but not at traditional brick-and-mortar casinos. Free slot machine games are available at most online casinos. These companies want you to try free versions of their games, hoping that you’ll upgrade to playing for real money.

You can also buy software and download apps that have free slot machine games.

I’ve never seen the point in playing such a game. After all, aren’t you just pushing a button and watching a meaningless animation?

The only thing that gives a slot machine game any meaning at all is the money that you have on the line, isn’t it?

The only reason I can see for playing a free game is to try out the casino software to see if you think you’ll want to play the real money games there.

You can find detailed reviews of casinos offering free slot machines here on this site.

Are slot machines addictive?

Some people are from a school of thought that says you can’t be addicted to slot machines because you’re not ingesting anything into your body. Slots aren’t like drugs or alcohol. How could you become addicted to them?

Those people are wrong.

Addiction is more complicated than that. Gambling game designers do their best to make these games addictive.

If you know anything about behavioral psychology or how the brain reacts to video games and gambling games, it doesn’t take you long to realize that slot machines are addictive.

Does this mean you’ll become a mindless slave to these games if you play them?

Not necessarily.

Addiction is more complicated than that, too.

The best thing you can do is look for warning signs that your gambling has gotten out of control. The most important warning sign is a lack of joy in the activity.

If you’re compelled to play these games but don’t enjoy them, you might have an addiction.

Get help.

Read a detailed guide to gambling addiction in general here on this site.

Can you buy and/or own your own slot machine?

The answer to this depends on where you live. In some states, slot machine ownership is completely illegal. In others, you’re allowed to own such games if they’re old enough to qualify as antiques. How old such games must be varies based on state law. But in all states, you must have a gambling license to own such a game and offer real money play to customer on it.

You can find a more detailed question and answer section elsewhere on this site.

Do casinos change the odds of winning on a machine that’s gotten hot or cold?

The random number generators on a slot machine are programmed to pay off at a certain percentage over the life of the game. But in the short run, anything can happen. Casinos understand this. They don’t need to re-program these games. They just let them run until the long-term expectation kicks in.

Conclusion

I hope you found this definitive guide to slots and slot machine helpful.

Would you do me a favor now?

Igt 5 Cent 1986 No Buttons Slot Machine Volume Controller

Leave a comment below and let me know what you think of this guide to slot machines.

What did I leave out that I should have included?

What questions do you have that I didn’t cover?

Did you see any mistakes?

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If you have a slot machine or you have bought one old used vintage slot machine and want to have some fixes to get it work then obviously you will think you need a machine technician. Many of you will even think of taking it to some repair station to get things done. But here in the guide you will find some of the repairs that you yourself can do with your slot machine and you need not need to join machine technical repair training school.

Like any other machines Slot machines too are a blend of electronic and mechanical components, that wear with age and require routine repairs. Before you begin to repair yourself do note that every slot machine that you have purchased whether old or new comes with installation and user guide manual. You need to read that many a times until you are familiar with each components and parts of the slot machine and understand thoroughly as how the slot machine works.

In your guide to repair slot machines you will find some common repairs that can be carried out by you, some videos to watch as well. If your slot machine has some complex issue then obviously you require a qualified technician.

Changing the Top Florescent Light

The top florescent light bulb is easily changed by following these simple procedures. The replacement bulb is an F15T8/CW 18″ 15 Watt bulb which is available at most hardware and department stores or may be purchased online at Ebay or Amazon or realslotmachinesforsale under the category ‘parts of slot machine’.

• Open the main slot machine door and ensure the door is fully open. Turn off the power to the slot machine. The power switch can be found with the main door open about midway down on the right side just inside the machine.
• If the machine is equipped with a top ticket printer, you must pull the bottom of the printer out far enough to see where the ticket paper is located, and note the area large enough to place a couple of your left fingers under.

• Remove the top metal trim strip which is a cover plate to the right of the ticket printer and/or is located along the bottom of the top glass. There are a couple of clips on the back of the metal trim strip that fit into notches on metal bracket which holds the top glass. The metal trim strip should be lifted upwards and outwards to remove.
• Once the metal trim strip is removed, the next step is to remove the top glass. Note that some top metal trim strips have a slot in the top that holds the top glass and they must be removed very carefully as to not damage or drop the top glass.

• You can now see the top glass is held in place by usually two or three clips that rise above the metal bracket behind the top metal trim strip. Now slowly lift up on the top glass from both bottom edges until the top glass until it is high enough to gently pull it forward and allowing it to slide down and away from the top track and clips holding it in place.
• Once the top glass has been removed, put it somewhere where it will not get knocked over or broken. You will see the florescent bulb in the middle of the top box area of the machine. Care should be taken removing the bulb as it may be very hot. Remove the old bulb by twisting the florescent tube about a quarter to half turn allowing the two prongs on the bulb to slide out of the fixture on both sides of the bulb.

• Remove and discard the old bulb. To install the new bulb, align the two prongs on each side of the florescent tube with the slits on each fixture in the top box of the slot machine. Twist the bulb into place normally using about a quarter to half of a turn. If the bulb is not secure or aligned, repeat the procedure.
• If your slot machine is an IGT S Plus machine, it is equipped with a florescent bulb starter. Then you can replace the starter when replacing the florescent light bulb. The starter is an FS-U Universal Starter. They are available at most hardware and department stores or may be ordered online too. The starter for the top florescent bulb on an IGT S Plus machine is located directly behind the florescent bulb fixture on the left side of the slot machine in the top box area.
• It is replaced by twisting about a quarter to half a turn as it is held in place with a bayonet type mount. Remove the old starter and discard. Replace with a new FS-U Universal Starter by aligning the two pins on the bottom of the starter with the notches in the starter receptacle, pushing it up into the starter socket, and then twisting it a quarter to half a turn into place.
• Prior to re-installing the top glass, turn the power switch on the right inside of the machine on to verify the bulb works properly. If it does not, turn the power off and check that the bulb is properly installed and secure. If replacing a starter, check that it is also properly installed and secure.
• After verifying the bulb is working, it is now time to replace the top glass. If your slot machine has a top ticket printer, ensure the ticket printer is still pulled out so you can place your fingers in the opening while replacing the top glass.
• Carefully and slowly lift up the top glass placing each hand under the bottom of the top glass. Slide it into the upper edge track on the top box of the slot machine carefully lifting it so it slides into the tracks while being able to push the top glass back far enough to clear the two or three raised clips on the metal bracket where the top glass holding track is located.
• Gently and slowly lower the top glass behind the clips so as to allow them to hold the glass in place. If properly secured, the top glass will not be able to slide down or out of its position. Keep a secure hold on the top glass until you are certain it is secured in the proper position.
• Replace the top metal trim strip by aligning the two or three hooks the back through the metal bracket that supports and holds the top glass. Once the hooks on the back are in place, gently push the top metal trim strip down and it should snap into place. If you have a slot machine with a top ticket printer, close it tight into position. Close the main slot machine door and you are ready to play.

Changing the Belly Glass Florescent Light

The belly glass florescent light bulb is easily changed by following these simple procedures. The replacement bulb is an F15T8/CW 18″ 15 Watt bulb which is available at most hardware and department stores or may be bought online as spare parts of slot machine.

• Open the main slot machine door. Turn off the power to the slot machine. The power switch can be found with the main door open about midway down on the right side just inside the machine.
• Facing the slot machine door, look on the right side of the door just around from bill acceptor area. You will see a knob sticking out that is approximately the size of the end of a regular pencil. This knob when pulled out releases the slot machine belly glass assembly (belly door) to fold down so the bulb can be accessed.

• There are a couple of very important thing to remember prior to pulling this knob to release the belly door. First try pulling gently on the knob. If it does not allow you to pull out and you have a lock installed directly above it, the lock must unlocked in order to allow the release knob to pull out. When pulling out the release knob, be ready for the belly door to fold down.
• Most of the time you must lightly pull on both sides of the belly door to get it to fold down, however always place your hand under it so it does not fall down too quickly causing the belly glass to break or crack.
• Once the belly door is in the down position, you will see the access to the florescent bulb bracket that is held in place by a small Phillips screw. Remove the screw and place it the coin tray so it will be handy when you need it after replacing the bulb.

• The long metal bracket that holds the florescent bulb must be slid slightly right or left so as to be able to lift it out of the belly door. Gently lift the metal bracket with florescent bulb out of the assembly far to be able to turn it over to replace the bulb. Be cautious as the bulb could still be hot!
• Grasp the metal bracket holding the florescent bulb and remove the old bulb by twisting the florescent tube about a quarter to half turn allowing the two prongs on the bulb to slide out of the fixture on both sides of the bulb.

• Remove and discard the old bulb.To install the new bulb, align the two prongs on each side of the florescent tube with the slits on each fixture that is on each side of the new bulb. Twist the bulb into place normally using about a quarter to half of a turn. If the bulb is not secure or aligned, repeat the procedure.
• Now turn the metal bracket that holds the newly installed bulb over and back into position in the belly glass assembly. Slid the bracket slightly right or left into position and replace the small screw which holds the metal bracket in place.
• If your slot machine is an IGT S Plus machine, it is equipped with a florescent bulb starter. So you need to replace the starter a well when replacing the florescent light bulb. The starter is an FS-U Universal Starter. They are available online and you can purchase one.
• The starter for the belly glass florescent bulb is located on the back of the main slot machine door on the lower right hand corner as you face the back of the door.

• It is replaced by twisting about a quarter to half a turn as it is held in place with a bayonet type mount. Remove the old starter and discard. Replace with a new FS-U Universal Starter by aligned the two notches on the bottom of the starter, pushing it into the starter socket, and then twisting it a quarter to half a turn into place.
• Prior to closing the belly glass door, turn the power switch on the right inside of the machine on to verify the bulb works properly. If it does not, turn the power off and check that the bulb is properly installed and secure. Also check to ensure the starter is properly installed and secured.
• Lift the belly glass assembly up and push it into place in the slot machine door. Ensure the belly glass door snaps into place and the knob on the side of the door is in its normal position. It is spring loaded so as to not allow the belly glass assembly to open unless it pulled. If the belly door appears to be in place, pull on both sides of the belly door to make sure it is locked and secure.
• If you unlocked the lock above the knob, re-lock it. Close the main slot machine door and you are ready to use your slot machine.

Changing the Push Button Bulbs

All of the slot machine’s push button lights such Play Max Credits, Spin Reels, Bet One Credit, etc. are easily replaced by following this simple procedure. The replacement bulbs are #161 on IGT S2000 machines and #555 on IGT S+ machines and may be purchased from online stores.

• Fully open the slot machine door. Look on the backside of the door. Each push button will extend down from the shelf on the door and will have a small wire bundle going to it. Identify which push button bulb needs to be replaced.
• Carefully pull down on the bottom of the push button area that is normally white and is where you will see wiring connected. Using your thumb and two fingers, pull straight down and the bottom portion of the push button should snap out.

• You will now be able to see the bulb in the top area of the lower push button assembly. Use caution as the bulb may be very hot. Pull the wedge bulb out and discard it. Notice the slot in which the bulb located.
• Place a new bulb in the slot noting the direction of slot ensuring the new wedge bulb is inserted so as to line up in the slot. Push the new bulb into place.

• Replace the bottom of the push button assembly by inserting it into the top portion of the push button assembly. The bottom portion will snap into position. Ensure that none of the wire connections have been accidentally knocked loose on the bottom of the push button. Note the push button light will not illuminate until the slot machine door is closed. Close the main slot machine door and you are ready to play.

Changing the Small Panel Lights

The small panel lights that illuminate the denomination amount and other areas behind the glass are easily changed. For denomination amount lights on the IGT S2000, a #73 bulb is needed and a #86 bulb is needed on the IGT S+ slot machines. They may be bought online from slot machine selling sites.

Here it is described as how to change the lights behind denomination amounts such as .25 Cents. Other small panel light bulbs are changed in the same manner.

• Fully open the slot machine door. Look on the backside of the door. Note the location where the denomination amount would be located near the center just below the slot machine’s center glass. The area will appear to be flat with a small bulb holder projecting out that is slightly larger in diameter than a regular pencil and is flat on two or four sides.

• This bulb holder is removed by simply twisting it a quarter to half a turn and then gently pulling it out of its socket. It is held in place by somewhat of a bayonet type mount.
• Once the bulb holder is removed, pull the wedge bulb out of the socket and discard the old bulb. Caution should be taken as the old bulb may be very hot. Replace the bulb by firmly inserting a new bulb into the socket of the bulb holder being careful to align the wedge bulb correctly into the slot.
• Take the bulb holder and look for two notches on each side of the opening where the bulb holder is inserted. Note there are two notches on the bulb holder. Align the notches inserting the bulb holder into the panel.
• Gently twist the bulb holder about a quarter to half a turn to lock it into place. Verify the bulb is illuminating, and if not repeat the procedure using a different new bulb. Now close the main slot machine door and ready to use.

Cleaning Your Slot Machine

This is common thing and all you need is usually nothing more than a damp cloth to clean the exterior cabinet of your slot machine. Never use any abrasive or ammonia based cleaners on the cabinet of the machine.

The slot machine top, center and belly glasses may all be cleaned on the outside by using a window cleaner. However if you own a slot machine with a frosted exterior glass or one that has any exterior decorated markings such as stars, a window cleaner should not be used as the cleaner may damage the exterior images. Care should be taken cleaning interior glass as a cleaner and cloth may damage labels or markings.

The inside of the slot machine should not require cleaning other than occasionally removing dust. This can normally be done with a damp clean cloth, however ensure the power switch has been turned off prior to cleaning.

When wiping dust inside your machine, be careful not to loosen any wires or connections. Do not use a damp cloth on the face of your reel strips as the playing symbols on the reel strips could come off or become torn. Also be very careful not to touch the back side of your reel strips with a damp cloth especially if the back sides of the reel strips are black. This can cause damage to this type reel strip.

When your Slot Machine Doesn’t Power On

When you get a slot machine and wish to locate or set up at your place, determine the household 120V AC outlet you are planning to use has power. Keep in mind some outlets are controlled on and off by a wall switch.

• With the slot machine unplugged from the outlet and surge protector, open the slot machine main door. Remove the coin tray by lifting up and pulling out the tray. Simply pull it out and down to remove the tray.

• The hopper is on the bottom floor of the machine and slides out on two base rails along two metal guides. Slide the hopper out slowly by grasping the handle with your left hand and supporting the hopper with your right hand. Do not use the black hopper bowl to pull the hopper out of the slot machine.
• On the lower right corner of the slot machine you should see the black power cord coming into the machine. The power cord plugs into the Power Distribution Unit which is located on the back wall of the slot machine.
• Verify the power cord is firmly plugged into place into the right side of the Power Distribution Unit.

• Place the hopper back into the slot machine making sure it slides in easily and completely with the base rails on hopper guides on the bottom of the machine. The hopper plugs into a receptacle toward the back of the machine. It is designed to fit in easily without using excessive force.
• The coin tray can be easily put back into place by ensuring the alignment pins on the coin tray match up to the top alignment holes on the bottom side of the machine. The tray should be pushed down into place. Make sure the tray is even when pushed into place. If the coin tray is not aligned and even, remove the coin tray, and repeat the procedure.
• Verify the power cord is firmly plugged into a good surge protector. Plug the end of surge protector into the outlet you have verified is good, and make sure the on/off switch on the surge protector is turned on.
• Now turn the power switch on the inside right of the slot machine to the on position and verify the slot machine is powered on by lights illuminating.

Jackpot Payout Reset

When your slot machine just hit a 25,000 credit Jackpot it now needs to be reset to continue playing. Depending on the model slot machine you have and the amount of the payout will determine the best course of action.

If you have an IGT S+ Slot Machine and your win is under the maximum payout amount specified on the center glass of the machine, the hopper may run out of coins or tokens. This is normally displayed by Error Code 3300. In this case it usually a simple matter of taking the coins or tokens that have been paid out and putting them back in the hopper allowing it to fully pay out. However, if you won a large jackpot that is “hand pay out”, then follow the steps below.

• First open the main slot machine door. Locate the Jackpot Key which is normally kept inside the slot machine in a plastic envelope on the side of the cash box. If you do not find it inside the machine, often times the Jackpot Key will be strapped with the main slot machine door key. It is a small key as pictured below.
• Take the key in hand and locate the jackpot reset which is a keyhole located on the right side of the slot machine. It is normally about two-thirds up from the bottom of the machine.

• Insert the Jackpot Reset Key into the keyhole. Turn the key only one quarter turn to the right. This will reset the machine, and once you close the main slot machine door, you will be ready to resume play.
• Note that if you turn the Jackpot reset key multiple times you may place your slot machine into a test mode and will thus delay your ability to continue playing.

Some of the Error Codes you get on Slot Machine

Error Code 3300 (IGT S+ Machines)

Simply put Error Code 3300 is normally telling you your hopper is low on or completely out of coins or tokens.

Open the main slot machine door. Look into the hopper. If it is empty or has just a few coins or tokens, place about 500 coins or tokens back into the hopper. Close the main slot machine door. In a few moments you should hear the sound of the hopper’s motor turning and soon the remaining coin payout will begin.

Error Code 3100 (IGT S+ Machines)

Error Code 3100 (Extra Coin Out Tilt) normally signifies either a jammed/stuck coin or token in the coin-out chute on the hopper, or the hopper coin-out sensor has detected the hopper may have paid out an extra coin.

• Open the main slot machine door. Remove the coin tray by lifting up and pulling out the tray. Simply pull it out and down to remove the tray.
• The hopper is on the bottom floor of the machine and slides out on two base rails along two metal guides. Slide the hopper out slowly by grasping the handle with your left hand and supporting the hopper with your right hand. Do not use the black hopper bowl to pull the hopper out of the slot machine.
• Inspect the hopper to determine if any coins/tokens appear to stuck or jammed in the hopper knife or the hopper coin-out channel.
• If a coin appears to be stuck or jammed, empty the hopper of coins/tokens for easier access to clearing the jammed coin/token.
• Once the stuck or jammed coin has been removed, place the hopper back into the slot machine making sure it slides in easily and completely with the base rails on hopper guides on the bottom of the machine. The hopper plugs into a receptacle toward the back of the machine. It is designed to fit in easily without using excessive force
• Refill the hopper with the proper size coins or tokens. The coin tray can be easily put back into place by ensuring the alignment pins on the coin tray match up to the top alignment holes on the bottom side of the machine. The tray should be pushed down into place. Make sure the tray is even when pushed into place. If the coin tray is not aligned and even, remove the coin tray, and repeat the procedure.
• Close the main slot machine door. The error code should be gone and the machine is ready to play.

Error Code 12 (IGT S+ Machines)

The 3.6 volt battery on the slot machine CPU Board normally lasts for years. However when an Error Code 12 is displayed, this is an indication the battery voltage has dropped below 2.9 volts and is now a low battery.

It is recommended to replace the battery as soon as possible. They can be purchased online from ebay, amazon or realslotmachinesforsale. When ordering a replacement battery, they will provide you with detailed instructions on how to change this battery which is located on the slot machine’s CPU Board.

In order to reset Error Code 12 temporarily, simply open and close the main slot machine door. It is important not to wait for a long time to replace the battery as data stored on the RAM may be lost. Replace the battery Asap.

Following are some of the other error codes that might interest you to solve your problem in repairing the slot machine

CODE	DESCRIPTION	PROBLEM
12	Low Battery	Battery voltage on processor board has dropped below 2.9 volts DC
21	Coin-In Tilt	Optic coin-in sensors were blocked
3100	Extra Coin Out	Stuck/jammed coin in hopper or optic sensor detects extra coin paid
3200	Coin-Out Tilt	Hopper coin-out sensor was blocked
3300	Hopper Empty	Hopper coin-out sensor sensor detects no coins were dispensed for 8 seconds or more. Hopper needs to be refilled with coins/tokens.
41	Reel #1	Tilt Designated reel is misaligned or malfunctioning
42	Reel # 2 Tilt	Designated reel is misaligned or malfunctioning
43	Reel #3	Tilt Designated reel is misaligned or malfunctioning
44	Reel #4	Tilt Designated reel is misaligned or malfunctioning
45	Reel #5 Tilt	Designated reel is misaligned or malfunctioning
49	Reel Mechanism Disconnected	A reel mechanism has become unplugged or the circuit is interrupted
61	CMOS RAM	Bad CMOS RAM data or data was cleared
62-0	Bad Game EPROM	Game program or data program check
62-1	Bad Data EPROM	Bad EPROM data
63	Processor Tray Open	Main processor door has been opened and closed since last game played
65-0	Bad EEPROM Device	Processor could not successfully read from or write to chip
65-1	Bad EEPROM Data	Data is invalid or corrupted
65-2	Game Type Mismatch	Game data om CMOS RAM does not match game data in EEPROM
66	Game EPROM Changed	Machine senses the game EPROM has been changed
67	Data EPROM Changed	Machine senses the data EPROM has been changed
68	Non-Compatible Data EPROM	Data EPROM is not a standard file
99-1	Bill Validator	Stacker jam
99-2	Bill Validator	Cash box removed
99-4	Bill Validator	Cash box full
99-5	Bill Validator	Hardware error
99-6	Bill Validator	Reverse bill detected

Hopper is Full and Coins Go Down a Chute to Bottom of Machine

Slot machines that accept coins were designed this way because when used constantly on the casino floor, hoppers could quickly fill. There is a coin level probe on side of the hopper that looks like a brass screw sticking inward toward the hopper bowl. This probe detects when coins/tokens are at a selected level, and will cause the subsequent coins/tokens played to go down a chute to the bottom of the slot machine.

Provided your slot machine sets on a regular casino slot machine stand with holes in the top and the holes are aligned with the slot machine, those coins which bypassed the hopper will go down the chute, through the hole in the bottom of the machine, through the hole in the top of the stand, and into the open area in the stand cabinet. As casinos have done for years, place a small plastic tub in the slot machine stand cabinet to collect these excess coins.

Retrieving Currency from the Cash Box

Though not all slot machines are equipped to accept currency in order to comply with certain laws but if your slot machine is equipped with a bill acceptor, bill transport and cash box, the bills in the cash box can easily be retrieved.

• Open the slot machine main door. The cash box door is located just under the yellow chute for the bill acceptor. Ensure the cash box door is fully open.
• On the right side of the cash box toward the top is a release level. Push release lever down and pull the cash box straight out toward you. If the cash box seems difficult or impossible to pull out, make sure you have pushed the release lever down.

• Hold the cash box in both hands and turn it upside down. Notice on the bottom of the cash box is a door which has two small finger sized holes on one side. Normally the door is held closed by a small piece of electrical tape so the bottom cash box door doesn’t come open while removing it from the cash box chassis of the slot machine.
• While holding the cash box with the bottom door up toward you, open the door and you will see where the bills are stored. The large spring expands as more and more bills are added to the cash box. Remove the bills by pulling them straight out.
• Close the bottom door of the cash box and re-secure the door using the same small piece of electrical tape. Turn the cash box around to the original position when you removed it from the slot machine.
• Align the flat top of the cash box with the flat surface at the top of the cash box chassis from which you removed it. Slide it firmly into place. Now close the cash box door and the main slot machine door and you are ready to use it for gaming.

All the content, graphics and videos in this post have been gathered by research for you from various online sources and hope this helps you as a guide to repair your slot machines. Note that many guide books and manuals too are there for you to buy from online stores which are handy to know as how to repair your slot machines. Just stay tuned at realslotmachinesforsale and know many more interesting information about slot machines.