Slots Wikipedia

Feb 13, 2020 | Reading time: 18 Minutes

What do you think is the most popular gambling machine that's also so simple that even a 5-year-old child could understand it? Invented in the late 1800s, this automated "one-armed thief" is the slot machine.

1. History

1. Learn the history behind slots:

San Francisco native Charles Fey made the first gambling machine, the "Liberty Bell," with an automatic payout system to instantly reward players. It had just three spinning reels that displayed five symbols each: the famous American Liberty Bell, diamonds, hearts, spades and horseshoes. If you got three bells to line up in the middle, then you won the grand prize of 50 cents. Other inventors made similar machines in the United States to simulate gambling in areas where such gambling was illegal. For example, they made varieties of vending machines that would occasionally deposit extra tokens to let you get bonus candy for free. However, courts later banned these machines. Today, you'd define a slot machine, or "slots," as any mechanical device that lets you gamble independently by inserting coins or a ticket into an arcade-game type of slot; then you either press a button or pull a handle to start spinning the internal -- or on-screen -- reels. If you see a winning combination of several matching symbols line up, then you win a prize and receive your payout in coins that the machine deposits in front of you. For big prizes, machines may print out a receipt or give another winning token that you can exchange for your money at the register.

1.1 Etymology

The term "slot machine" refers to the slots where you deposit your bets and withdraw your winnings from the machines. In Great Britain, they use the term "fruit machines" in reference to the traditional fruit symbols appearing on the machine's reels. In Australia, they're "pokies," which is short for "poker machine."

1.2 Terminology:

Your "payline" on any slot machine is generally a horizontal line running across the center of the screen, and your winning combination of symbols must appear exactly on that line to win. You'll find that "multi-line" slot machines can be more exciting to play because you can win by hitting winning combinations in more than one line. A traditional multi-line, reeled slot machine could have up to five possible paylines, and video slots can have hundreds of paylines. "Multi-denomination" slots accept almost any amount of cash that you have on hand, and they'll convert your bet into the equivalent credits you need to play. You still get to select how much you'll bet on each spin. "Bonus rounds" are random opportunities you receive during a spin to win extra prizes or free spins. You collect your winnings from traditional slot machines from the "coin hopper" -- where the coins pop out at the front-bottom area of your machine when you're ready to cash out. Your "candle" is the light on top of your slot machine that illuminates when you need assistance to get change or you have a problem with the machine. It can also light up automatically to call the staff once you've hit a big jackpot! Veteran slot-machine players get hooked on the "taste" of the machines, which is the tiny payout they get intermittently as an intentional ploy to give players more hope for a big win eventually. "Progressive jackpots" -- which everyone dreams of -- are a grand prize that steadily increases as the machines gradually collect more money from many different players over time. Finally, each machine has its own "pay table" -- a chart listing how much you'll win by landing on each different combination of symbols.

1.3 Technology Development of Slot Machines

By the 1960's, more states legalized slot-machine gambling, and electromechanical slots without levers on the side started becoming more popular. Then the leap to video slot machines began in 1976 with a new machine made by the Fortune Coin Company in Las Vegas that was a great success. Just two decades later, touch screens appeared on slot machines before they even became commonplace on cell phones. New advancements in technology continue to upgrade today's slot machines with 3D screens that you don't need to wear glasses for. Plus, online, interactive slots have led to new apps that let you gamble on-the-go right from your Internet-enabled mobile devices.

1.4 Slot Types with Pros and Cons:

Here's an overview of the pros and cons for the most common slot-machine types: Three-reel slots are variations of the original slot machine, and they don't deliver many payouts. However, they give you the best odds of winning it big out of all the other slot machines with more reels. Five-reel slots give you more options to bet on 25 different paylines or more, so you can win more often ... but the payouts are generally smaller than three-reeled slots, and your odds of winning a big jackpot are much less. Five-reel slots usually offer more bonus rounds and often appear as video slots though, which makes them more fun to play. Seven-reel slots are a modern style of slot machines that may have 10 paylines or more depending on their vendor, so you can have more possible ways to win. Their main appeal is that their jackpots can be much greater than three or five-reel slots, but of course, the reason why the jackpots are more valuable is because your odds of winning are even less than on machines with less reels.

1.5 Slot Denominations and Odds of Winning

What are your odds of winning on different slot-machine denominations? The universal rule to all slot machines is that the higher the betting denomination of your slot machine is, the better your odds of winning are. Penny slots: These machines only accept multiples of one-cent bets. According to Nevada's Clark County report on house wins for all of their slot machines during the year 2012, casinos had an almost 11-percent return on penny slots, and the lowest return was from $25 slots: 3.97 percent. If you're new to slot-machine gambling, penny slots are a fun way to start because you're less likely to lose a lot of money while playing. Still, that fact also means that penny slots have the worst odds of winning big bucks out of all slot machines. Nickels, quarters, dollar and five-dollar slots: These machines accept five-cent coins, 25-cent coins, one-dollar and five-dollar bets respectively. In Nevada, the house returns from these slot machines are 5.96 percent for nickels, 5.74 percent for quarters, 5.64 percent for dollars and 5.51 percent for five dollars. Therefore, your chances of winning don't vary greatly between these machines -- although you have slightly better chances to win more on these machines than you do on the penny slots. Overall, the odds vary from one machine to another even within the same casino. Since the law doesn't require most places to list your actual odds of winning at these games, this information often isn't public. Please note that the odds of winning at any slot machine will be the lowest odds of winning at any game within a casino.

2. Game Types:

2.1 Classic Slots

have three reels and one payline, and you pull a large lever on the side to start spinning the reels. Usually winning combinations are three matching symbols or two matching symbols plus one wild or bonus symbol. Each win is worth different cash prizes. The more you bet, the more you'll win if your spin is lucky. Most classic slots accept up to three coins at a time, and you decide to bet with either one coin or more per spin.

2.2 Video Slots

can have as many as five to seven reels and 100 possible paylines because they contain no rotating mechanical parts like classic slots do. Simply push a button to start. Then when you hit a jackpot, you'll see the screen light up to excite you with special animation. Some newer versions like "Slotris" have even blended elements of Tetris and Jenga into the game to make it more interesting.

2.3 Fruit Machines:

originated in the United Kingdom. These three-reeled fruit machines randomly award "nudges" that let you move one reel a little more to complete your winning combination. If you get a "hold," you can freeze some of the reels during a spin to increase your chances of winning. If you can hit the buttons at just the right moment during a "cash-ladder" or "bonus-board" play, then you'll get even more chances to score big.

2.4 Pokies:

are Australian and New Zealand style video-slot machines that typically have more than three reels. They also operate off of randomly generated results from a computer program. Each pokie has its own special theme, and they offer bonus features like free spins with options to double your money when you get lucky. They also display different messages at the top of the screen to "talk" to you.

2.5 3D Slots:

are video-slot machines that immerse you in the gaming world by using special screens that feature three-dimensional images that pop out at you -- and they don't require any special glasses. Deluxe versions of 3D slots may have well-cushioned seats with surround-sound booths to enhance the experience. These slots often have progressive jackpots, which give a higher payout after no one hits a big win for an extended period of time.

3. Slot Machine Classes 101: How Slots Work :

While it may seem like a classic slot machine with physical reels is working on randomly spinning wheels, they're often not random in the way that you think they are. Newer slot machines with the traditional pull-lever on the side are usually connected to random-number generators inside the machine. Based on whichever random number the computer chip selects, the computer processor sends quick digital pulses of electricity to internal step motors, which stop the spinning reels according to where the computer chip tells them to stop.

3.1 Computerization Facts

All computerized slot machines, which feature a video screen and don't actually spin physical reels, simply display spinning animations on the screen to entertain you. In reality, a computer chip inside the machine is selecting randomly generated numbers on each "spin," and it will display different results on your screen based on the number combinations it picks. Therefore, the odds of winning will always remain exactly the same on every spin and on every slot machine. However, computerized slots will always look more appealing because the manufacturers can program them to give different probabilities to each symbol on each reel. That means that while the random-number generator still decides whether or not you win at slots, you are more likely to see winning symbols appear more often on the screen than they would in real life, as if you "just missed" that big jackpot quite often.

3.2 Random number generators:

Modern advances in random-number generators have now found a clever way to get around their greatest weakness: Every random-number generator will eventually repeat its number sequence -- albeit after an extraordinarily long amount of time. Highly skilled computer programmers had found ways before to exploit machines by hacking their number sequence since the machine's program had predetermined results. These days, machines have upgraded random-number generators that actually generate new numbers constantly -- even when you don't play the machine -- at speeds of up to a fraction of a second between new number picks. Essentially, even if you knew how the program of the slot machine worked, you'd still have no way to know exactly where in the random-number sequence the machine actually is at any given point in time.

3.3 Payout percentage

What's your payout, or "payback," percentage? Every country, and even each state within that country, has different laws regarding their minimum payout percentages for slot machines. One of the lowest payout percentages in the United States is 75 percent, the minimum for machines in Las Vegas. Some payout percentages go as high as 95 percent, but you must keep in mind that these numbers represent the total percentage of money that the machine pays on average to everyone as a whole compared to the total amount of money that the machine collects. In other words, don't plan on getting 95 percent of your money back when you play. These percentages are based on probabilities, and it could actually take years of playing to eventually get around 95 percent of your money back in winnings. Based on independent analyses by Professional Actuary Michael Shackleford, you'd be lucky if you had a one-percent chance of winning big on most slot machines.

3.4 Linked machines:

Linked slots offer the promise of bigger, dream-worthy payouts since they're connected to a set of multiple machines and therefore have a bigger pool of money to draw from. Linked slots most commonly offer progressive jackpots. The biggest slot-machine prizes are offered by area-wide linked machines, those connected between many different casinos that may even be in different states. An independent operator manages all these linked machines and takes a percentage of the returns while the casino housing the machine also collects their own percentage too. The bigger the prize is, the greater your chances are that your machine is linked ... and your odds of winning are even less since these machines have to compensate for additional operating fees.

3.5 Fraud

Can fraud beat the machines? The latest big case in slot-machine fraud scandals struck in December 2014 when the FBI reported that they'd arrested four Russian nationals for developing electronic devices to cheat the Aristocrat Mark VI slot machine by predicting its behavior by communicating with foreign Internet servers. They allegedly developed a plan to hit 10 different casinos across the United States before their arrest.

3.6 Jackpot errors

Do jackpot errors really happen? Internal bugs in the software programming of your slot machine can cause it to accidentally award you more money than you originally betted on. Such bugs appear randomly -- like in 2010 when a Colorado casino wrongly awarded more than 10 million dollars to a player by mistake due to an internal program error. Unfortunately for this player however, the state's gaming commission reviewed the machine's playing records to discover the flaw before paying out those winnings.

3.7 Skill stops

What's the advantage of skill stops? Popular in Japan on “Pachislo” slot machines and also on British fruit machines, the skill-stop feature is an extra button on the machine that lets you freeze a spinning reel at will to get an extra chance at winning. However, the random nature of the machines is still so great that finding patterns to help you know when to hit the skill-stop button is almost unachievable. The Japanese version has a metal ball that you try to aim and shoot at just the right time to land in a lucky slot.

4. FAQ About Slots Online

4.1 How much of the payback comes from the jackpot?

It's a long-standing tradition that most casinos will never tell you this information. Some experts estimate that the jackpot is less than two percent of the total payback or returns from slots.

4.2 Who has the best slot paybacks?

Very few websites advertise their slot-payback rates. You can ask these companies directly, but do realize that they have no legal obligation to answer your question. In fact, laws regarding online gambling aren't as clear as laws regulating the gambling at land-based casinos. One exception is, which states that "Gold Pirates" and "Jack in the Box" give you their best odds of hitting a jackpot: a 1 in 250,000 chance.

4.3 Where are the highest-paying slot machines?

In the real world, you'll find the highest rates of return from slots around Northern Las Vegas and Reno in Nevada. Online, it's very debatable which slot machines actually pay out the most due to conflicting sources and a lack of openly published rates from the game creators. With that being said, gaming aficionados point to the five-reel "Thunderstruck II" by Microgaming, the five-reel "Immortal Romance" by Microgaming and any online slot game from Mummy's Gold Casino.

5. Compare Slots Around the World :

5.1 United States and Native American casinos

In the United States, Las Vegas and Atlantic City are the top two destinations for slot-machine players that offer a legendary amount of games to choose from. Since Native American casinos have more property available to build on with less residential building restrictions than regular cities in the United States, these casinos are generally the largest in the country. For example, one of the biggest is the Foxwoods Resort Casino, located on the Mashantucket Pequot Indian Reservation in Connecticut with more than 6,300 total slot machines. Even the the Chickasaw Nation of Oklahoma tribe owns the WinStar World Casino in Thackerville, Oklahoma -- the biggest casino in America that's coincidentally not all on reservation property.

5.2 United States Legislation for Classes I, II and III

Within the United States, the Indian Gaming Regulatory Act law clearly defines three different categories of gambling games that each have specific restrictions.
Class One games include all traditional Native American games, which only tribal governments can monitor.
Class Two games include bingo and all cards games played solely between players. Tribal governments regulate these games completely, as long as they obtain a gaming ordinance approved by the National Indian Gaming Commission, or "NIGC."
Class Three games include every other game in a casino. These games must be legally approved and require an ordinance from the NIGC.

5.3 Canada

Many casinos throughout Canada are government-owned, so the governments do collect a percentage of the returns directly. However, their odds of winning on slot machines are roughly within the same range as those machines that are also popular on the Las Vegas strip. Far less indigenous tribes from the Assembly of First Nations invest in casinos than the tribal communities of the United States, partially because Canada's government doesn't allow them to independently conduct gaming activities.

5.4 Australia

Australian slot machines, or "pokies" as they're often called, have been most popular in the New South Wales state since 1956. Their most popular features are "scatter" win variations where symbols don't have to line up exactly for you to win. One special feature of machines in Victoria especially that you won't find in most other casinos is that they come with an information button you can press to see the actual payback percentage, odds of winning and pay table for that particular machine.

5.5 Japan

Japanese “Pachislo” slot machines theoretically involve more skill to play than your other typical slot machines, and they don't accept any kind of currency -- you'd have to buy tokens to play. Every reel has a button below it that allows you to stop the spinning reel whenever you choose while playing so that you're not "entirely" gambling. This addition is important because gambling has been notoriously illegal throughout most of Japan even since 2010. You can win tokens that earn you prizes from the house like specialty cigarette lighters or souvenir collectibles. Some machines have a metal ball that you try to aim and shoot at just the right time to land in a lucky slot.

5.6 United Kingdom

The United Kingdom's Gambling Act of 2005 puts its games into four main categories based on the betting levels and available prizes:
Category A games are adult-only games with unlimited prizes. They were meant for "super casinos," which aren't approved yet in Britain.
Category B games are games betting from 1-10 pounds for adults only to win up to 4,000 pounds.
Category C games are for one-pound maximum bets with a top prize of 70 pounds, and they're for adults. Casinos can often have more of these games onsite than other high-stakes games.
Category D games are for players of all ages with bets usually less than one pound. Maximum prizes are eight pounds or less,

6. Slot Clubs

If you're serious about playing slots, join a slot club! Slot Clubs are one of the most sought-after benefits of gambling in land-based American casinos. Many are often free to join. The more you play, the more complimentary drinks, meals, hotel rooms, cash-back bonuses or other prizes you can receive. Every slot-club member plays with a unique card that tracks their playing history to determine how many benefits they're eligible for.

Was this helpful?