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?
HOW SLOT MACHINES WORK This is what is known about casino slot machines: The RNG (Random Number Generator) The Random Number Generator (RNG) is the brains of the slot machine.
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.
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).
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.
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.)
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.
More About the Subject:
- 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.
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.
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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.
How Slot Machines Work 2014 Dodge
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.
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.
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By Jon H. Friedl, Jr. Ph.D., President
Jon Friedl, LLC