Slot Machines - An Online Bet-Guide

Known affectionately as “one-armed bandits”, slot machines have a reputation as either easy money or a waste of casino floor space. Love ‘em or hate ‘em, you can’t deny that this simplest of games in the casino is also the most profitable. Depending on the source you trust, slot machine profits are responsible for as much as 85% of casino business, a figure that adds up to hundreds of millions of dollars a year.

The reason some gamblers look down on slot machines is the same reason that many people flock to them--slot machines don’t require any gambling knowledge or skill. The cost of a single round on a slot machine adds to the democratic feel of the game. Some slot machines can be played with a bet of a single penny.

The biggest development in casino gaming in recent years is the expansion of legal wagering into the world of the Internet. An explosion in online gambling has not passed the humble slot machine by. Online slot machine games are a dime a dozen, from simple penny slots to more complicated progressive and even linked online slot games. As laws about online gambling have become more and more clear, new opportunities for slot players have followed. A recent law in New Jersey, for example, has legalized online gambling for state residents through licensed casinos in Atlantic City, including online slot machine play.

Slot Machine History

Whether you call them slots, fruit machines, poker machines, or “pokies”, the name of the game is the same. Slot machines have a long and interesting history, and have taken many forms over the years.

The slot machine as we know it today was invented by Charles Fey. Prior to Fey’s invention, coin operated games of chance had existed for a while, but not in any form that we would recognize. Generally, these games were built around poker rules, promising a free drink or a cigar to players who “rolled” up a decent poker hand. The problem, as Fey saw it, was that a coin operated gambling machine should have more limited rules than poker in order to pay out for all possible combinations.

Charles Fey simplified the rules and invented a simple automatic mechanism that contained three reels with ten symbols per reel. Fey’s first slot machines consisted of horseshoes, spades, diamonds, hearts and bells, with three bells offering the top prize. Modern slot machine players would find Fey’s invention very familiar-- players inserted a coin into a slot and pulled a handle to start the wheels spinning. At the time of his invention, patent laws were such that Fey was unable to own the copyright for his invention. Instead, he placed the machines in bars and other less than wholesome places and collected 50% of the take as his fee.

Fey’s invention came in 1887, and over a hundred years later, his original slot machine design is the basis of all slot design today. Fey simplified the game to include just three reels and ten symbols and set the standard for all coin operated slot gaming for decades.

The early days of slot machines were not exactly player-friendly. Bar owners and slot machine renters would often “better the odds” by altering the symbols on the reels to the house’s advantage. With no regulatory group to control slot machine alterations, it was common for an establishment to stack the deck against the slot player, making a “top prize” result (a jackpot of fifty cents in the early 20th century) nearly impossible.

So where did today’s standard slot machine symbols come from? In areas where gambling on slot machines was illegal, it became common for the prize to be issues in the form of different fruit-flavored chewing gums. The flavor of the gum became the symbol on the reel of the game—this is where the popular cherry, melon, and banana symbols come from. The bell is a holdover from Charles Fey’s original game design, the Liberty Bell. The BAR symbol, still very common in slot machines, comes from the logo of the Bell Fruit Gum Company, an early supplier of prizes for these gum machines. It’s interesting to note how little has changed about slot technology, even though these days you can play the games online or even in video game form.

It wasn’t until 1963 that another big advancement in slot machines would be made. The first fully electrical slot machine appeared at Bally that year, a machine called Money Honey. Up until 1963, slot machines were mostly analog, and required lots of attendants to pay out in the case of big winnings. The Money Honey machine was able to have a “bottomless hopper” and provide automatic payout, reducing the overhead of the casinos and increasing the excitement of slot play. Money Honey could pay out up to 500 coins without the help of a slot attendant, and this machine was soon so popular that other casinos couldn’t help but invest in their own fully electrical machines. This led directly to the move away from “classic” slot machine design (with a giant arm on one side, etc.) and in just a few years, electronic games were standard in Vegas.

How Modern Slot Machines Work

When you talk about “modern” slot machines, you’re talking about two or three very different types of game. Some casinos still offer versions of old mechanical slot machines, in which the player actually has to pull a level to get the reels spinning. Compare these old-school designs with the ultra-modern Internet-based slot machines and you get an idea of how many different types of slot machines are offered by modern casinos.

But when you say “modern slot machine”, you mean electrical slot machines. Essentially, these machines work on the same principles as the old mechanical machines, with a few different electronic components.

In modern slot machines, the outcome of each “pull” of the lever is actually determined by a computer inside the machine, not by any kinetic motion or anything at all to do with the machine’s reels.

The computer inside your standard modern slot machine uses motors to turn each reel and to stop it at a point determined by a random number generator. These motors are controlled by minute electrical pulses, also controlled by the machine’s computer. These tiny pulses are capable of moving the motors a precise specific increment.

Alright, so that word “determined” up there makes some people suspicious. It sounds like the machine pays out according to a schedule—but even though the slot machine’s computer brain tells the reels where to stop; the games are not set up to pay out at certain times. The random number generator at the heart of the machine sees to it that every “pull” on a slot machine lever is as likely to hit the jackpot as every other pull.

Random Number Generators

Every slot machine that is powered on is constantly spitting out random whole numbers hundreds of times per second. You’ll never see these numbers, but they’re there, spinning in infinity as long as the power is on. These whole numbers, digits between 1 and several billion, are what determine the outcome of your “pull.”

Every time you pull the machine’s lever or press the button to stop the reels, the machine’s internal computer listens to the next few numbers spit out by the random number generator. Those numbers are what determine if you win or lose—the outcome of your game is decided long before the symbols pop up.

Here’s a quick example of how a random number generator determines if your bet is a winner. The computer records the first three numbers spit out by the random number generator—each number corresponds to a different reel. If the first number spit out by the RNG is 100,000,000, the computer takes that number and puts it through a simple equation to determine the reel position.

That giant number is first divided by a standard value—32, 64,128, 256 or 512 depending on the machine’s manufacturer. If our machine divides by 32, our first number is 3,125,000 with a remainder of 0. Since there are only 32 possible outcomes, each value becomes a “stop” on the machine’s virtual reels.

Each reel calculation will have a different value outcome, linked to a different result on the machine’s visible “reels.” Sounds way more complicated than it actually is—really, you should think of slot machines as little calculators, constantly coming up with random numbers and comparing them to pre-programmed equations and tables.

How Online Slot Machine Games Work

Since slot machines no longer require a physical “pull” of the lever, it was only a hop and a skip to create virtual slot machines that can be played online. The Internet lends itself to modern slot machine design—small and simple calculations controlled by random number generators and the simple push of a button. When you think about it, modern slot machines are an easier design than most other casino games. When the outcome of a gambling wager is based solely on random numbers, that game is easy to design for use on computers.

Online slot machines work exactly like modern electronic machines. The biggest difference is that you don’t need a physical gaming surface (the machine itself) to spit out the random numbers and turn them into a commodity that can be wagered on. Bypassing the slot machine itself and offering online gamblers the opportunity to put their money up against RNGs was just a matter of designing some simple software and offering it for download.

Probability & Slot Machines

It won’t take you long to find people who want to sell you “slot machine secrets” or ways to beat slot machines. The Internet is overloaded with eBooks and other means of disseminating false information about slots. The easiest thing to do with slot machine systems is to ignore them. None of them work, and you can’t beat a random number generator.

Does that mean that there’s no way to figure out odds? Not at all.

The odds of hitting a particular symbol or a jackpot combination depend entirely on how a particular slot machine’s virtual reel is set up. The actual odds of hitting an image on the slot machine’s physical reel depends on how many of a machine’s “virtual stops” correspond to an actual stop on the virtual reel. Okay, don’t pull your hair out, it is simpler than it seems.

An average slot machine gives just one virtual stop for every jackpot payout spot on the reel. That makes the odds of hitting a jackpot symbol on just one reel 1 in 64. If you’re playing a basic slot machine with three reels, that means that the chances of hitting the jackpot image on all three reels is 1 in 262,144.

This is the main reason that modern slot machines often have multiple paylines and use many more stops on their virtual reels—big jackpots naturally require longer odds.

Another way that modern slot machines control jackpot payouts is by adding extra virtual stops to the losing symbols just above and just below the jackpot symbol. This means that a slot player is far more likely to hit the non-winning symbols than to hit the jackpot symbols. Not only does this protect the machine’s jackpot, it gives the player that “almost hit the jackpot” feeling that tends to encourage them to feed even more money into the machine.

All this complexity and variation means that figuring out a particular slot machine’s odds is next to impossible. Understanding basic slot probability is a good thing, but you can hardly ever apply this basic understanding to an active slot machine, especially the machines with huge jackpots, multiple pay lines, and progressive features and bonuses.

Slot Machine Payback Percentage

With all this variation possible in terms of payout and jackpots, how are slot machines kept fair? After all, the ability to alter the possibility of jackpot winnings could give the House an unfair advantage.

The answer is something called “payback percentage”. This refers to a specific percentage of the money put into slot machines eventually paid back out to the slot machine player. This is given as a whole number between 0 and 100—a payback percentage of 90 pays the casino back a full 10 percent of all money put into it. Even when a machine gives away the other 90 percent of the money put in, the casino will always come out on top. You’ll never find a payout percentage above 99; it wouldn’t make sense for the casino to offer the game.

Depending on the state in which you’re gambling, the law about payback percentage will be vastly different. Most areas of the world require at least a 75 percent payback, though casinos tend to program their machines to payback at least 90 percent to keep slot players interested. This is why some slot machines appear to be “tighter” or “looser” than others—the machines actually pay out at slightly different percentages, though finding out a machine’s payback percentage is little more than a pipedream. What sense would it make for the casino to advertise a specific slot machine’s percentage?

Slot Machine Strategy

Because of payback percentage and random number generators, most slot machine strategy guides are full of useless information. Many people will tell you that they know when a machine is “loosening” or “tightening”, driven in part by their own inflated sense of their gambling acumen, and in part by small fluctuations in a machine’s output that is part of the computer system it runs on.

The fact is, slot machines don’t tighten or loosen in front of your eyes. Since the internal computer is constantly coming up with new random numbers, a slot machine player has even chances of hitting a jackpot on every single pull of the bandit’s handle. Any notion of a machine “tightening up” or “loosening up” is all in a slot player’s head.

It's natural for humans to see patterns where they don’t exist, but if you remember that a slot machine depends on random numbers to determine winners, you can avoid all the usual slot machine superstition.

Here are some actual words of wisdom from a veteran slot machine player:

1. Always bet max. Machines with multiple bet options, even machines that don’t offer multiple pay lines, only pay out maximum jackpots to players who make max bets. On machines with multiple pay lines, slot players choose how many lines they play based on their bet amount. Minimum bets only pay on the single straight line running across the reels. Larger bets mean more playing options.

2. Manage your bankroll. There are a few different slot machine bankroll management systems, none of which are effective. The idea behind wager and bankroll management is to have a realistic view of how well you’re doing and a set amount of losses or winnings that leads to getting up from the machine and walking out of the casino. Determining these things ahead of time can save you a large loss or a bad beat later on in your gambling session when your brain may not be as sharp as it should be.

3. Read the pay table. Playing at a slot machine without understanding the pay table is asking for trouble. Many slot machine disagreements arise because a player has a limited understanding of the pay table—and since this table is posted on every legal slot machine in the world, you are responsible for understanding how a machine pays out. It isn’t the fault of the casino if you didn’t bet max and now you want to cash in a jackpot that you didn’t earn.

Some Slot Machine Terms You Should Know

Action – The total amount of money you've wagered during a slots session. Slot regulars can keep track of their action on special slots club cards offered by casinos.

Basic Slots – Slot machines with a single payline and a static jackpot. These jackpots do not change over time like a progressive jackpot machine does. Also called straight slots.

Bet Max – A button on the slot machine’s playing surface that lets the slots player bet the maximum number of credits allowed per spin of the slot machine. Playing “bet max” offers the highest possible payouts for a given slot machine.

Big Bertha – The giant slot machines used in casinos to grab player’s attention. Usually containing multiple reels and making lots of noise, Big Bertha machines are there to draw in casual slot machine business.

Big Hit – Hitting a jackpot combination.

Bonus Multiplier Slot Machines – A specific type of slot machine that offers bigger jackpots (“multipliers”) in an attempt to force slot machine players to bet the maximum number of credits.

Carousel – A group of slot machines. Carousels are usually made up of similar machines, such as “dollar slots” or “nickel slots.”

Cold Slots – Slot machines that do not seem to pay out very often. Also called “tight slots.”

Credits – When you put coins into the slot machine, they become “credits.” If you’re playing a dollar slot machine, a twenty dollar bill inserted into the machine will give the player twenty credits on that machine.

Doubles – Specific winning combinations on slot machines. When these symbols come up two or three at a time, they can double or triple a player’s winning amount. (Those are called "triples" rather than "doubles.")

Fixed Value Slots – Slot machines where the amount and coin size of a bet cannot be altered. That means a player gets one denomination and one coin per spin. (As opposed to unfixed value slots.)

Hit Frequency – How often a particular machine pays out. Think of it as an average payout. You are looking for low numbers when it comes to hit frequency—a machine with a hit frequency of 5 pays out, on average, one out of every five spins.

Hold Percentage – How much of a player’s money the casino keeps on average over the long run. A 95% slot machine keeps five dollar while returning ninety-five dollars back to the player.

Hot Slots - Slot machines that appear to pay out more often than other machines. These are also called “loose slots.”

Line Bet – A bet on a given line on a multi payline machine. (Multiple payline slot machines give the player the option of betting on only one or a specific number of lines.)

Linked Progressive Jackpot – Also known as a “wide area progressive”, this is when two or more slot machines have linked jackpots that get larger until someone wins. These machines will be clearly marked.

Multi-line Bonus Slot Machine – Slot machines that offer more than one payline are called multi-line bonus slot machines. These slots vary by casino—the biggest of them can have up to fifty paylines or even more.

Multiplier – When a slot machine offers payouts that can be multiplied under specific conditions, it is called a “multiplier machine.”

One Liner – A slot machine with only one reel. This usually means slot players only have to line up three symbols to win.

Onesies – A “onesie” is a slot player who plays just one coin or one credit at a time. This is usually done to determine a machine’s average payout or to “test” a new machine.

Payline – The line on which winning combinations on the slot machine must land in order to win a payout.

Pay Table – The most important part of any slot machine, the pay table is a small sign on every slot machine that tells what all the winning combinations are and how many credits they win, including winnings that are based on bet amounts. Pay tables are crucial when you’re playing slots to win money and not just for fun.

Progressive Slot Machines – A slot machine that offers a jackpot that continues to grow until it is won. These are sometimes linked to other progressive machines.

Reel Stop – Any one position on the reels of a slot machine.

RNG – A computer program running in the brain of the slot machine that that selects the results at random from all possible sequences.

Scatter Pay – Slot machines that sometimes pay out even when no symbols match. This is a bonus feature offering payouts for rolling a single symbol, regardless of what other symbols you roll.

Slot Club – If you plan on spending any money at all at slot machines on your next Vegas trip, joining a slot club is the way to go. These member-exclusive programs pay out prizes and special rewards to club members in exchange for a certain amount of play time on the casino’s slot machines.

Slot Host – Less and less common as slot play becomes more automated, slot hosts are casino employees whose job it is to serve slot customers and handle any issues in the slot machine banks.

Slot Testing – This is what big-time slots gamblers do to a new machine or bank of machines. Usually, slots players will set a specific number of coins to play to determine a machine’s average payout.

Three Liner - A three liner slot machine is one with three reels. This very basic type of slot machines requires a player to line up three identical symbols to win a cash payout.

TITO - Also known as Ticket In / Ticket Out, TITO slot machines print tickets with winning amounts printed on them when players decide to cash out a machine. This allows the player to easily switch between machines.

Two Liner - A two liner slot is a more complex version of the three liner. These machines have just two reels to line up three symbols and win, but if six symbols are lined up, the win amount doubles.

Up / Down Slot Cycle – Because a machine’s average payout is determined over a long period of time, the words “Up / Down slot cycle” came to refer to the periods where a machine’s payout appears to fluctuate away from an average. Naturally, fluctuations exist when you’re talking about average payouts, and Up / Down refers to these fluctuations.

Wager Management – A strategy of slot play bankroll control, wager management means breaking up your bankroll into smaller amounts for a predetermined amount of slot play time. Usually, wager management leads slot players to cash out while they’re up.

Zig Zag – Multi-line payout machines don’t just allow for wins across the line—on some of these machines, you can win a payout for completing certain symbol combinations in a zig-zag formation.