How Does Casino Slot Machines Work

Most modern slot machines are designed to look and feel like the old mechanical models, but they work on a completely different principle. The outcome of each pull is actually controlled by a central computer inside the machine, not by the motion of the reels. The computer uses step motors to turn each reel and stop it at the predetermined point. Introduction to Kentucky Slot Machine Casino Gambling in 2020. Kentucky slot machine casino gambling does not include games of chance, which are strictly illegal. Instead, Kentucky has competition-based electronic gaming machines at four out of its five pari-mutuel wagering racetracks.

Slot machines are an extremely popular form of gambling. The premise is simple: you insert a coin, pull a lever, and reap in cash rewards if the symbols on the reels align in a certain way. Slot machines test your luck and intuition, and, despite the simple rules, they are not boring in the slightest.

Slot machines use catchy music, fun graphics, and interesting symbols to hold the player’s attention. But how slot machines work? What are they made of and how do they determine when to pay out and when to disappoint the not-so-lucky players?

This article uses advanced terminology. If you are new to slots, you may want to check out our complete glossary of slot game features.

The Anatomy of a Slot Machine

So how do slots work? In order to find that out, you’ll need to go through video slot parts. When playing a land-based slot machine, you will see the following components:

Coin Slot/Bill Slot

This is where you put your money into the machine. You can also insert a cashed-out ticket into a slot machine and spend your winnings on additional spins.

Reels

Slot machines usually feature three or five reels, but you can occasionally come across machines with as many as ten reels! Reels are the spinning mechanisms that make the vertical positions on a slot grid rotate. Each reel has a certain number of “steps” where it could stop, and each step either contains a symbol or is blank. A typical slot machine contains about 20 stops on each reel, but this can vary.

Lever

In older slot machines, the lever would actually set the reels in motion. In modern slot machines, however, the lever just triggers the casino game’s software, which, in turn, makes the reels spin.

Play buttons

Slot machines may feature several different buttons. The most common include “Spin Reels”, “Play One Credit”, “Play Two Credits”, “Bet Max Credits”, “Cash Out”, and “Request Change.”

Coin Tray

In the past, once you would hit the “Cash Out” button, your coins would cascade out of the machine and pool in the coin tray. Now, however, it is now more common for the machine to print you a cashout voucher. These are redeemable at a redemption machine or at the cashier’s cage. Alternatively, you can insert it into another slot machine (usually through the bill slot) and go for some more spins.

Payline

The payline is the horizontal line that you can see in the center of a slot machine’s screen. In order to land a winning combination, the symbols must align on an active payline. The number of paylines available can vary from game to game, but you can only win payouts on the paylines that you place a bet on.

If there are ten paylines available, and you only bet on two of them, you can only reap those two payline’s rewards. Some machines require users to pay one credit for each payline that they would like to activate. Other machines may require multiple coins to activate a single payline.

Some slot games allow players to adjust the payline’s direction, while others are fixed. Paylines can run left-to-right or take on a zig-zag shape.

If you’re also interested in how all of these parts come together, make sure to watch this How It’s Made feature on casino slot machines:

Pay Table

A slot machine’s pay table will display all of the game’s winning combos and corresponding payouts. It will also display any special bonus, wild, or scatter symbols. Furthermore, the pay table will show the game’s current jackpot and indicate whether or not the machine is progressive. You should always check out a slot game’s pay table to educate yourself on all possible wins, payline configurations, payout odds, and information for bonus events.

Displays

Every slot machine will clearly display the basic information relevant to its users. Some common displays include:

• Credits played. This display shows the exact number of credits that the player is betting on each spin.
• Credits. This will show the player how many remaining credits they have. When the display reaches 0, the player must deposit additional coins through the coin slot in order to keep playing. Keep in mind. each credit will align with the denomination the game requires. If a player is using a 25-cent machine and inserts a $10 bill, the display will show that the player has 40 credits available.
• Insert Coin. This display shows that the slot machine is not currently activated. Anybody simply has to insert bills or coins into the machine to begin playing.
• Winner Paid. This will show how many credits were won on the previous spin, which would be added to the player’s total on the Credits display.
• Error Code. This display will only activate if a slot machine is malfunctioning. It will show a code that assists a staff member in identifying the problem.

Feel free to also watch a video guide on how a casino slot machine works below:

Types of Slot Machines

There are many different kinds of slot machines, some of which can be difficult to find. Here are some types of slots that you might come across and a short guide on how they operate.

Single-Coin Machines

These used to be very popular but are now much harder to find since most slots now accept dollar bills or require multiple coins per spin. Because these machines only accept one coin per spin, the house does not rake in as much revenue during a period of time as it would when using a multi-coin machine.

However, some old-fashioned casinos still use these types of machines. If you want a more classic gaming experience, and you want your credits to last for more spins, try out a single-coin machine.

Multipliers

Not to be confused with Multiplier symbols, a multiplier machine takes multiple coins and has a payout ratio that corresponds with the number of coins that a player uses on a spin. This type of machine was introduced in 1987 and is now the most popular type of slot machine found in modern casinos.

Multiplier machines still allow players to partake in single-coin play, but often players will choose to make the maximum bet.

Buy-Your-Pay Machines

Buy-Your-Pay machines allow players to bet between 1-5 coins on each spin. The number of coins inserted is what determines the game’s number of activated winning combos. For instance, if a player inserts only one coin, 3 “bars” would be a winning combo, but not 3 cherries. On the other hand, if they insert more coins, then both combos would be considered winning ones.

You can identify this type of machine by taking a look at the pay table. If it shows that more coins unlock extra winning combos, then you know it is a Buy-Your-Pay machine.

This kind of machine is not as common as multiplier machines. Many players avoid using them because it can be frustrating when they are just one coin shy of cashing out a great combo.

Multiple Payline Machines

Most slot machines only have one payline, which is in the middle of the game’s screen. On the other hand, a multiple payline machine has more than one active payline, as its name implies. This gives players a more exciting experience and offers more win potential.

However, players will typically need to pay an additional credit to activate each payline. When a payline is activated, it will light up.

Land-based casinos’ multiple payline machines typically offer 2-5 paylines, but sometimes more. On the other hand, online machines could have 50+ paylines!

Progressive Machines

Progressive machines are linked together by one jackpot, which can grow to gigantic proportions since it grows anytime a player inserts a coin into one of the network’s machines. When a player finally hits the jackpot symbol combination, the pool will reset. Some US gambling venues have linked together slot machines across entire states! Over the years, this type of slot machine has become very popular, since everybody wants to try their hand at winning a jackpot that would make them a millionaire.

Progressive jackpot slots have become especially popular in online casinos, and slots across various websites can be linked, as long as they use the same software platform.

Big Berthas

A Big Bertha slot machine simply refers to a machine that is gigantic and features 3+ reels. Some even feature as many as 8 reels, and each reel has 20 symbols! These machines are typically located near the entrance of a casino, to draw in attention. However, they don’t offer a great payout percentage.

Multi-Game Machines

A multi-game slot machine allows the player to switch between various games without having to sit at a different machine. For example, one multi-game machine might offer slots, blackjack, and video poker. In addition to this, multi-game machines will usually support many different currency denominations.

Other Useful Terms to Know

Hit Frequency

Hit frequency refers to how often a winning combination will land on the reels. If a machine has a high hit frequency, this means that winning combos will land more often. Machines that hit often don’t have a great payback percentage. Conversely, slot machines that have a low hit frequency will usually have a pretty significant payout rate.

Payback Rate

The payback rate, also known as payback percentage, refers to the amount of money that gamblers win, compared to how much they wager. Slot machines’ payback rates typically fall between 82% to 98%.

RNG

Each slot machine has a built-in Random Number Generator (RNG), which is an algorithm that ensures that each landing symbol is totally random and is not dependent on a player’s previous spin.

Now that you know all the details about slot machines, come try out some virtual ones at CasinoChan!

A slot machine simply takes a dollar and gives 80-98 cents back (it's rare to find a slot machine with a payback of over 98%).

But, of course, it does this in the long run.

Since playing slot machines seems insane on paper, what makes slot players spend so much money on these machines that are often referred to as one-armed bandits?

That'll be all the psychological factors.

Slot Machines and Psychology

A machine that just takes money and does nothing else would unlikely succeed, so the way slot machines have worked around that hurdle is offering a theoretical chance to win money, even if you lose money on the machine in the long run.

And that chance makes people play the machines. First of all, who wouldn't want to win a lot of money for basically doing nothing? That's appealing even if the odds were against you.

Additionally, people rarely realize just how much of a house edge slot machines have, and how much better it would be to play games like blackjack with optimal strategy.

Usually, the bigger the jackpot, the more players are willing to play the machine. After all, what's $50 spent on a machine that may give you a life-changing sum of money? (Co-incidentally, progressive jackpot slots, the ones that have more than a million dollars in jackpot prizes, give you the worst winning odds.)

Our desire to win big-time allows slot machines to play another psychological trick on us: the near-miss situations, which happen because slot machine reels are weighted differently (more about that lower on this page). It encourages us to keep on playing since we 'came so close' to winning life-changing money.

At live casinos, the most popular slot machines are often placed in the places where most people can see them. This takes an advantage of a psychological tendency called Social Proof (or as I like to call it, 'monkey see, monkey do'). Some say that casinos even place the machines with the highest hit frequency to where everyone can see them - I find this believable, but I have no proof.

Seeing lots of others play and win is one heck of a psychological trick. The sound of winning that a slot machine makes is affiliated deep in our mind with something positive, as is the sound of coins clinging and clanging against the metal disposer of the machine (the sound of money!). It's easy to see why someone walking in to space like that would be hooked.

So I thought it would be important to understand how slot machines work from a psychological point-of-view first - since psychological factors are what make us play slot machines - and now that you understand the basics of slot machine psychology, let's move on to the technical aspects.

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Random Numbers and Paytables

When someone believes in a slot machine's hot and cold streaks, it's called Gambler's Fallacy, and for a good reason. 'Hot' streaks happen, 'cold' streaks happen in the sense that sometimes, when numbers are chosen randomly, they happen to be of similar sort for X times in a row.

It's like receiving pocket aces twice in a row at poker - it's unlikely (in fact, there's a X% chance it happens) but it does happen sometimes. Does that mean the deck of cards is 'hot'? Or when you flip a coin and you get heads five times in a row, is the coin 'hot'?

Of course not. When things happen at random, they do. They're unpredictable. Anything can happen, and at some point probably will happen.

But the point is, you have no way of knowing what the future holds for a slot machine. Every spin of the reels is an independent trial, which means the previous game has no influence on the next game. Everything starts over and the chances of winning are the same with each spin of the reels, regardless of whether someone's lost ten spins in a row or just hit a jackpot.

Why would anyone design slot machines that get 'hot' or 'cold' anyway? If they did, players could tell when to play and when not to play. It makes no sense. Casinos are much better off creating slot machines to which there are no 'winning systems' available.

So slot machines use a random number generator (from now on referred to as 'RNG') to, well, generate random numbers for each reel. These numbers are between one and a couple of billions (let's just say a lot of numbers).

Casino Slot Machines Winners

And there's a symbol assigned to each number - for example, if the RNG would pick numbers between one and a billion, the game had ten symbols and each were as likely to come, there would be a 100 million numbers assigned to each of the symbols.

But lot machine symbols are never equally likely to come; the ones that pay the most are the hardest to get. Therefore different symbols have a different amount of numbers assigned to them. (The odds of winning the Megabucks jackpot are somewhere in the one out of 50,000,000.)

But the point is, the RNG assigns numbers to each reel and those numbers correspond with symbols that have been assigned to them. The RNG is not influenced by previous results; it deals a new, random set of numbers with every spin, regardless of what's happened.

Interestingly, the moment you press Spin or pull the lever, your fate has already been sealed. Spinning reels stopping one by one is just theatrics; they make the game more exciting and enjoyable.

Now, the slot machine must also know which symbol combinations are winners and how much they pay. For this, slot machines use EPROM chips. They tell the slot machine winning combinations and define the paytable.

When a casino wants to change the payback of a machine, they change the EPROM chip (or the settings of the chip). Not long ago casinos had to physically change the chip which was quite a bit of work, but now many casinos can change the settings of the chip externally.

How Does Casino Slot Machines Work At Home

There are rules, though. In Nevada, for example, casinos aren't allowed to change the settings four minutes before and after someone has played; this eliminates the myth that casinos change the settings while you're playing.

So either someone physically changes the chip or there has to be a four minute time window before and after someone's played. (While the settings are being changed, the slot machine screen should have a message stating that some sort of 'configuration' is happening.)

How Does Casino Slot Machines Work Videos

That's pretty much it. There are a lot of psychologal tricks involved, but technically the RNG assigns random numbers to each reel and the EPROM chip determines the winning combinations and paytables, which together determine the payback (or 'return') of the machine. The less it pays back, the more you're going to lose on the machine in the long run.

How Do Casino Slot Machines Work

More About the Subject:

How Does Casino Slot Machines Work

• Vegas Click: Michael Bluejay's comprehensive explanation of how slot machines work. In my opinion, the best one out there.
• Wizard of Odds: Michael Shackleford's slot machine advice -- the site also features an extensive FAQ section for slots.
• Gambling Captain: If you're looking for a short but insightful read on the basics of slots (or other casino games), this is a good site to visit.