How Do Modern Slot Machines Work

Someone hit a jackpot on the machine you just left - so you would have won that jackpot if you kept. If you’re a beginner, you should understand the answers to these seven important slot machine questions: 1 – How Do Slot Machines Actually Work? Slot machines used to be mechanical games powered by levers, springs, and spinning reels. Modern slot machines retain the lever and the spinning reels, but they’re both just for show, mostly. Slot machine video from casino expert Steve Bourie that teaches you the insider secrets to winning at slot machines and how a slot machine really works. On a slot machine, a random number generator (RNG) picks a random number for each reel, which each number matching a stop on its reel. Then the machine directs the reels to stop on the spots selected by the RNG. Note that by the time the reels are spinning, the game is already over.

Most amateur gamblers believe that if a slot machine hits the jackpot, then it immediately goes ‘cold’. They also believe the opposite is true; if a machine runs cold for hours, then it’s ‘due’ for a big payoff. But if you look inside modern slot machines, you learn the cold hard truth. Every single pull of the lever has equal odds of winning, and those odds are steep.

Since the earliest mechanical slot machines, gaming manufacturers have weighted the machines to tweak the odds. If you look closely at the reels of old machines, you’ll find many more blanks and low-scoring symbols than pots of gold, especially on the third or final reel. This creates the famous ‘near miss’ effect.

Modern slots have replaced the gears, cranks and stoppers with precision step motors and random number generators (RNG). When you pull the crank on a modern slot, a built-in RNG selects three numbers between one and 64. Each number corresponds to one of 22 spots on the three reels. The trick is that half of the numbers between one and 64 correspond to blank spots and only one random number matches the jackpot symbol. The odds of nailing the jackpot are 1/64 x 1/64 x 1/64 or one in 262,144.

Modern slot machines use a computer to generate random numbers, and these determine the outcomes of the game. The important thing to remember is that the results are truly random. The game doesn’t work on any kind of cyclical basis, and slot machine jackpots don’t become due. Slots don’t get hot or cold, either.

The lever is just for show. Three internal step motors spin each reel and stop them precisely at the positions chosen by the RNG. Still feeling lucky?

Return vs payback

There is no such thing as a ‘loose’ or ‘tight’ slot machine. In modern casinos, slot machines are programmed to deliver a precise return percentage, somewhere around 95 per cent. That means 95 per cent of the money that goes into a slot machine is paid back out to the players and the casino keeps the rest.
But here’s where things get tricky. The return percentage is not the same as the payback, which is the actual amount of money you win or lose during each gambling session at a slot machine. If you sat down at a slot machine for eternity and pulled the lever an infinite amount of times, your payback percentage would be exactly 95 per cent. Likewise, in a casino full of gamblers, the collective machines will pay back roughly 95 per cent of the total money gambled during the course of a day.

Unfortunately, you are only one person and you don’t have infinite pulls. So your odds of winning are equally good or bad every pull. You could lose all day and that doesn’t mean the machine is rigged. And it doesn’t mean that the guy who wins the jackpot found the ‘loose’ machine. He just got very, very lucky.

Top 5 Facts: Gambling stats

1) Big jackpot, big odds

The odds of winning the jackpot on a ‘progressive’ slot machine like Megabucks is one in 50 million, although if you are that one you’re likely to become very rich.

2) ‘Easy’ money

68 per cent of people who gamble at Las Vegas play the slot machines most often. And there’s a large target market as nearly 90 per cent of visitors to Las Vegas gamble.

3) The house wins

In the United States, gaming was a $92 billion industry in 2007, double what it was a decade ago. And in the UK, there were 143 casinos as of 31 March 2009.

4) United States of Slots

Even though Nevada is widely considered the gambling state, there are 37 US states with some form of legalised electronic gaming device like slot machines or video poker.

5) Vegas’ most wanted

The Nevada Gaming Commission maintains a list of 35 people who are not allowed in any casino or gambling establishment. Only one of them is a woman.

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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.

How do modern slot machines work videos

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 farright column typically shows the winning jackpots available when betting maximum credits.

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.

The casino isn’t making money if a player spends time studying or reading until they do understand rather than playing the machine.

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)

Slot Machines For Sale

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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Have fun, be safe, and make good choices!
By Jon H. Friedl, Jr. Ph.D., President
Jon Friedl, LLC