How Do Slot Machines Work
Introduction to How Slot Machines Work
In these series of posts, I continue to answer the most common questions about slot machines asked via Google searches. This post explains the simple question of how slot machines work.
In this post, I will discuss the operational components of a slot machine from the point-of-view of a slots player. Meaning, the various interface areas on the front of a slot machine. These player interface areas include:
- Service Light
- Bonus Display (Optional)
- Pay Table
- Players Club
- Results
- Play Console
- Ticket In, Ticket Out (TITO)
Additional relatively minor interface areas are not listed or shown below. These areas are the locations audio speakers, audio volume control (optional), display lights, lever arm, and a hearing aid jack to accommodate those with a hearing disability.
- With the rise of modern technology, the traditional slot machine has given way to newer, more advanced mechanics. Inside each machine is a computer that operates on a code or mathematical equation. This slot machine algorithm works as a random number generator, also known as an RNG.
- The slot machines have a computer chip inside that runs the Random Number Generator (RNG). The RNG is continuously cycling through numbers even when the machine is not being played. These numbers correspond to the stops on the wheel that display the winning or losing symbols that you see when the reels stop.
What about slot machines makes them such reliable money makers? In part, it has something to do with casinos’ ability to hide their true price from even the savviest of gamblers.
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Service Light
A slot machine’s service light is generally located at the very top of a slot machine to be easily visible to casino employees. Because of this uppermost location, it’s also known as the candle within slots terminology.
Slots players can switch on the service light by activating the service button on the player console. Or, it will enable by itself if the player wins a hand pay jackpot or the slot machine develops a service fault. Faults might include lack of paper, a full cash-in condition, mechanical or electronic tampering, or an internal electronic failure such as CPU overheating, etc.
Modern casinos have a slot attendant call/dispatcher communication system using a headset and microphone. This setup is helpful for spotting problems on the casino floor. An activated service light automatically notifies the casino operating system. The casino dispatcher then informs the slot attendant responsible for that section of the casino.
Once the notification is sent out, a lit candle is of little practical use. At best, it guides the responding slot attendant the last few feet to the customer needing attention and, also, provides some reassurance to the waiting customer.
Slots players may activate the candle for a multitude of reasons. In general, they do so to deliberately call a slot attendant to their location, for any of a host of reasons only limited by imagination.
Pro-Tip #1: Service Light
Sometimes slots players need to leave a slot machine briefly but don’t want to give it up to someone else. If this break is relatively brief, say 10-15 minutes, use the service button to call over a slot attendant. The slot attendant can temporarily lock up the slot machine at the request of the player.
The slot machine can be unlocked later by the player via insertion of only their service card … or after 10-15 minutes when the temporary lockout automatically expires. For the specific length of lockout times, ask any slot attendant at your casino.
Bonus Display Area
If a specific slot machine has a bonus round available, then it will often have a second display area. Video slots may use the same primary display screen but abruptly display the bonus round game theme instead. However, video slots most often have a secondary display screen available for bonus rounds.
The Bonus Display area is optional and dependent upon the specific slot machine model. The location of this bonus display varies. More often than not, it is high up on the slot machine to be viewable by other players from a distance.
Casinos offset their losses by offering slot machines with bonus round display visible from a distance. Frankly, wins on these highly visible and usually loud bonus displays are seen by many. This obvious win encourages other casino patrons to play slot machines.
Pro-Tip #2: Bonus Round
Bonus rounds generally cannot be activated unless that slot machine’s maximum credits are bet. By not betting maximum credits, the player automatically lowers their odds of winning.
If betting maximum credits on a specific denomination slot machine is not affordable, pick another affordable slot machine. I discuss this approach in detail at Choosing Slot Machines.
Pay Table Area
The Pay Table area lists information on the jackpot amounts for specific reel combinations. It can also display some or all of the game theme rules. This area may be permanently displayed on the slot machine, or possibly only available through an interactive series of images available by touchscreen.
In either case, all possible wins may or may not be displayed. Sometimes the list is highly abbreviated, and displays only the highest jackpots, due to space limitations. Other times, mainly with touchscreen displays, a series of images can be switched between to view every possible winning combination.
However, pay tables typically provide the highest value jackpot. Slot machine game themes with multipliers or “wild” reel symbols have their most top value jackpots being the result of these reel symbols. Alternatively, it may not show all multipliers or “wild” symbols in the tabulated list of win-reel combinations. Instead, they may be in writing along the edge of the paytable interface area.
But, with large touchscreens has come the capability to provide full paytable information along with game theme rules. Some slot machines now have this feature and, perhaps, more will have it in the future.
Many paytables show the number of credits that would be won for a specific combination of reel symbols. Or, they may show a monetary amount. In either case, these tables have separate columns for winning combinations dependent upon how many credits are bet. The far
Some examples of credit and denomination combinations are:
- 1-credit slot machines having a $100 denomination
- 3-credit slot machines having a $5 denomination
- 5-credit “quarter slots” having a $0.25 denomination
- 300-credit “penny slots” have a $0.01 denomination
Pro-Tip #3: Pay Tables
Frankly, learning the paytable of any slot machines played is a relatively easy way to improve the odds of winning at slots. Many typical slots players believe there is no skill involved in winning at slot machines. Casinos gently foster this misunderstanding, as it is to their benefit. Don’t fall for it.
Traditionally, slots players find it acceptable to play slot machines with visual succinct paytables. Frankly, casinos would instead have their customers spend their time playing a game they don’t understand
One easy-to-learn skill to improve the odds of winning at slots is choosing which slots to play based on their paytables. I discuss this in detail at Choosing Slot Machines.
Players Club Area
The Players Club area contains a card reader, numbered keypad, and a small display. A security feature of players club cards is for players to choose a PIN to enter when they wish to access their player account.
Newer-style slot machines have a touchscreen display, which removes the need for a physical keypad. Meaning, it’s part of the touchscreen display.
Bets can be made on a slot machine without a players’ club card. At most casinos, it typically is not required. Neither is the PIN needed to play the device or view basic information. For example, a running total of reward points earned during the current play session is generally on display.
The PIN is required, however, to:
- access certain portions of player’s casino account
- transfer banked funds
- activate “free play” provided by the casino as a complimentary gift
Results Area
The Results interface area is where the reel combinations are seen after making a bet. Whether a video slot machine or a slot machine with physical reel, this is where the results of a bet are provided.
Interpreting whether a reel combination is a winner requires an understanding of the paytable. This result is fundamental to how slot machines work.
Of course, the slot machine will immediately display the results. A small display beneath the reels shows:
- the total amount of money or credits available in the machine
- how many credits most recently bet
- the jackpot amount won if any
Jackpots are usually in credits, where each credit equals the denomination of the machine rather than the amount bet, as well as a monetary amount.
Player Console
The Play Console typically has physical buttons, a cash/ticket reader, and a ticket printer. The buttons include:
- Cash Out for requesting the removal of any player funds in the machine
- Service to request a casino attendant
- A Series of Buttons for selecting the number of credits to bet, or placing the maximum possible bet
- Cash Out for removing any remaining bankroll
- Repeat to making another bet for the same credit(s)
- Denomination to select a specific bet denomination (optional)
The player console may have several possible button configurations, dependent upon the model of the slot machine. Given how often game themes are switched to maintain the interest of players over time, it is common for player consoles to be standardized over many machines within a casino.
Also, it is becoming common for consoles to have embedded displays visible through their semi-transparent button covers. This array of small screens are linked together to show visually stunning composite images displayed across the entire array of buttons.
Ticket In, Ticket Out (TITO)
By the beginning of the 21st Century, the use of coins was removed from casinos. This removal was for the sake of convenience of both the casino and customers. Both had issues with handling so many coins. Customers because of the difficulties inherent with carrying so much weight, but also gambling delays due to full (or empty) slot machine coin hoppers.
How Do Slot Machines Work In Casinos
Casinos had issues with coins as well, including customer complaints due to delays caused by a full (or empty) slot machine coin hopper. This inconvenience was a coin logistics issue, which also included higher costs of maintaining a larger vault space and coin processing equipment and services. As casinos became more popular, coins became more difficult for everyone.
As a result, Ticket-In, Ticket-Out technology was pulled into casinos. They are now integral to how slot machines work. This automation is the same technology that was beginning to be seen in Automated Teller Machines (ATMs). Once proven out, this slot machine technology was here to stay like so many others.
Summary of How Slot Machines Work
I’ve discussed the operational components of a slot machine from the point-of-view of a slots player. This explanation of how slot machines work included the various player interface areas on the front of a typical slot machine.
There are additional relatively minor interface areas. These areas include audio speakers, audio volume control (optional), display lights, lever arm, and a hearing aid jack to accommodate those with a hearing disability.
Related Articles from Professor Slots
Other Articles from Professor Slots
- Previous: Where Were Slot Machines Invented Historically?
- Next: Why Do Slot Machines Say Bar on Their Reels?
Have fun, be safe, and make good choices!
By Jon H. Friedl, Jr. Ph.D., President
Jon Friedl, LLC
Slot games started out as big machines with drums that spun symbols around when people pulled a long lever. These one-arm bandits couldn’t be further from how the games that you know and love, work today. Today’s slot games can be found online or via slot apps, just like the games you can find at House of Fun. These work with a click of the mouse or a swipe and tap of the smartphone screen and you certainly can’t see drums of the reels spinning around. Of course, there is plenty going on behind the scenes to make sure that you can enjoy a fun and exciting game with great sound effects and graphics, unique features and mini games and even progressive jackpots. Here we’ll look at the guts of the mobile and online slot machines that we have all grown to love in order to understand how they are designed and how they work.
The Ins and Outs of Video Slots
When slot games first moved online in the 1990s, people were nervous of a game where they couldn’t see the actual reels spinning. But, the way that these games work has proved to players that they are not only fun, but fair and reliable.
The most important part of the way that video slot games work is the Random Number Generator (RNG) and here’s where it gets a bit technical. The RNG produces a constantly random sequence of numbers. When you click spin, that sequence will stop, telling the symbols where to land. This means that the symbols will land in a random way every time you spin.
How is the Random Number Generator Random?
The RNG does not have a memory so it can’t remember if you’ve won or lost in the past and it can’t remember how the symbols landed on the reels on past spins. It works with a mathematical equation, but the results are not pre-programmed.
The RNG is constantly producing numbers so that each time you press the Spin button, the sequence will be different. In other words, no 2 spins will be the same, giving you a unique playing experience every time you sit down to play!
How Does a Slots Game Work?
The RNG is the guts of the slot machine; it’s behind the scenes and we don’t see it. Let’s take a look now at the parts of the slot games that we do see.
- Reels – There are slot games that aim for a more authentic look and feel and these have 3 reels, similar to the original land-based machines. These are known as classic slots or fruit machines. More common are the video slots and these generally have 5 reels, although you may find games with 6 reels. These are the types of games you will find at House of Fun.
- Paylines – This describes how many lines of combinations of symbols there are in the game and also explains how many chances you have to win as you play. Video slots games generally have between 5 and 50 paylines, but there are games with more. You can choose how many paylines you want to play and this will affect the size of your bet. You will only be paid out for combinations that land on active paylines so the more paylines you bet on, the bigger your chances of winning!
- Rows – The number of rows in a game describes how many symbols there are visible on each reel at a time. Online slot machines most commonly have 3 rows, but 4 is not unusual. At House of Fun, during some bonus features, the number of rows increases to give you even more opportunities to create winning combinations!
- Ways to Win – Some games do not have paylines, but they have something called Ways to Win. These Ways to Win are calculated by how symbols land with respect to other symbols. Games commonly have 243 or 1,024 ways to win. If a game increases its number of rows, such as during the free spins feature of some of House of Fun’s games, the number of Ways to Win will go up.
- Features – Features are what make games unique and fun. At House of Fun, there is an incredible range of features, including free spins, mini games, gold symbols, progressive jackpots, Classic Star jackpots, Rapid Fire jackpots and more.
How Mobile Slots are Unique
Mobile slots use the same RNG as online slot machines so whether you are playing on your computer or on a mobile device, every spin will be unique and fair. The games also look the same as online slot machines with great graphics and sounds, unique features and impressive bonus games. But, at House of Fun, we know you love to play on the go and have your favorite games right in your pocket with you, so we have developed our games to be played on mobile devices also. These games are designed to fit perfectly onto a smartphone or tablet screen with a specific layout and display that suits the size of the screens. The swipe and tap features of mobile devices are also perfect for slots play and these are incorporated for intuitive and simple playing. Not only that, but mobile players will have access to the same incredible progressive jackpots as online players.
Playing Slots via Mobile – The Final Say
How Do Slot Machines Really Work
For slots lovers, mobile slots are a windfall! Slots apps, such as House of Fun, allow you to carry around your favorite slot games wherever you go. You can whip out your smartphone or tablet whenever you have a few minutes and play games that have been especially designed for your mobile device. These have all the fairness and randomness of online slot machines, as well as all the great bonuses and features that players have come to love. If you’re wondering whether it is a good idea to play slots via mobile, the answer is a resounding yes! Simply collect your free coins and start spinning the reels to win!