There are thousands of slots at casinos and online, with new slot titles being dreamt up all the time. While millions of people enjoy these games, few know how they work behind the scenes. On this page, we explain how slot machines work and the essential playing concepts that can make a difference for your bankroll.

How To Understand Slot Machines Displays

Playing casino slots can be a fun (and sometimes addictive) hobby. These machines can bombard your senses with lights, sounds, or vibrations, all of which are designed to entice you to play either in a casino or online. Because of their ability to draw attention, slot machines tend to be the most popular type of game at a casino.

Slots have evolved drastically from the first mechanical three-reel devices. These days, most slots are electronic, showing animated symbols on HD screens. Many have elaborate themes, some tie-in with popular music, TV or movie franchises. Bonus games might vary widely, though the underlying technology based on random number generator (RNG) software is standard for all games.

Below, you’ll find out more about how RNG software works, key factors like return-to-player (RTP) percentages and the many varieties of slots available.

Also, we share how to take advantage of bonuses and loyalty schemes to get the best bang for your bucks from slot play.

1. The technology used to judge the coins’ validity kept getting better and better, which made tricks like fake coins obsolete, or at least much harder to pull off. Slot machines started using a light sensor to register payments and figure out whether the coins were fake or real.
2. If you are new to the idea of playing slot machines, it is important to understand how to read a slot machine before you head out onto the floor and begin playing the slots. One thing that should be understood is that although slot machines may look as though they are all the same, that is not the case.

How does the RNG software work on a slot machine

Each time you press the spin button, the slot machine will generate a random sequence of numbers that determine the outcome of that spin. The RNG happens independently every single time you play.

While it can seem that sessions go in streaks, this is not the case. Each spin is an independent and random event. If you had hit the spin button a split second later, the RNG would have given you a different outcome. Both online slots and live casino slots use RNG software.

Auditing companies test the software to ensure the spins are fair and that (over the long run), the returns from each game are equal to the published amount.

Mechanical slots use a different system, which involves “stops” on each reel. Lower paying symbols will have a lot of stops, which means they occur (along with blanks) more frequently. Those with higher-paying, jackpot symbols will have the lowest number of stops, making it rare to line them up.

What is the RTP percentage?

Slots return most of the money put into them to players; however, this varies from 90% to 97%. You will often find “return to player %” in the helpinformation.

The primary factor affecting the RTP of a slot is its denomination, which is the size of your stake per line. The range goes from penny slots up to dollars. While the stake might be the same (30 lines on a 10 cent slot equals $3, and three lines on a $1 slot also equals $3), the higher the denomination, the better the returns and all else being equal.

While this is a usefulguideline, it is not enough information on its own to check whether a slot is worth playing.

How volatile are slot machines?

What you can’t tell from the RTP% is how volatile an individual slot is. Some games give you regular, smaller payouts, while others pay big prizes though do it infrequently. This is known as the “variance” of a game.

The highest variance slots have big jackpots.

If someone wins a million occasionally, then the overall returns (to non-jackpot winning players) naturally need to be smaller to balance this. You’ll find a lot of casino slots that pay small prizes of less than your spin amount, as well as bigger wins. These lower your variance, though not necessarily the overall returns.

Getting the most from slot bonuses and promotions

Both live and online casinos have bonuses and promotions to attract new players. Taking advantage of these is a great way to top off your bankroll.

Live casinos offer free play or matchedplay when you sign up for their loyalty schemes. You can then track your gameplay and get further rewards depending on the amount you gamble.

How To Understand Slot Machines For Beginners

Online casinos offer a greater range of bonuses. Look out for some of the following:

• Match Deposit Bonuses: The 100% match bonuses based on your first deposit are at most online casinos. Some are at 200% or more.
• No-Deposit Bonuses: Many state-regulated casinos in Pennsylvania and New Jersey will give you bonus cash to try their games for merely signing up. These bonuses are usually in the $10-$30 range.
• Rebates on Losses: An alternative incentive is to offer bonus credits if you lose your initial deposit. The terms of these deals (for example, playthrough) can vary widely.
• Free Spins: These can be linked to a deposit, or be completely free. You will usually have to wager any money you win a specified number of times.
• Tiered Loyalty Schemes: Online slots enjoy loyalty rewards as well as their live counterparts. You’ll get bigger and better bonuses the more you play.

How to win at slots – Don’t fall for slot machine myths

Over the years, many tales have emerged regarding slots. If you visit any casino, you’ll find people trying to win at slots by rubbing or tapping the screen for luck or saying that a particular title is their “lucky game.”

Below are 5 common myths that people believe will help them win:

1. Due to Pay: Slots work by generating random numbers every time you hit the spin button. Except for special games such as “must pay by” jackpots, a game doesn’t have any memory of the outcome of previous spins. If you hear someone saying that a game is “due to pay,” treat this as nonsense.
2. Secret Hacks: Contrary to what you might find online, there are aren’t any secret hacks or systems to beat slot games. If there were a guaranteed way to win thousands, this would not be on sale for $30 on some shady website.
3. Kill Switch: Many players fear that the casino “sees” them winning and hits a hidden switch to have the game take their money. While the RTP of a game may be changeable, this is not something that can happen without a full reset. What players here are experiencing is natural variance.
4. Playing with a Loyalty Card Reduces Wins: Some people claim they do better without their card. This comes under the selective memory category; the software-controlled random outcome and predetermined RTP can’t be changed by a card that tracks you for loyalty rewards.
5. My Friend, the Winner: Conversations about slot play often results in claims of a lucky friend consistently winning on them. Over any reasonable sample size, this is simply incorrect. Possibly those small losses are easily forgotten, and the big wins easily remembered and shared.

Playing slots online

Regulation for online gambling is rapidly expanding on a state-by-state basis. For most states, only sports betting is currently on the statute books.

If you live in New Jersey or Pennsylvania, you will be able to enjoy online casino games, too. These casinos have hundreds of slot options. They range from versions of classic casino titles to brand-new games developed for online use.

However, if you live outside of a regulated state, you can play online slots legally via sweepstakes gambling sites. These include the popular Chumba Casino and LuckyLand Slots. Both use laws designed for sweepstakes contests (used by many businesses for marketing) to let you enjoy colorful and unique online slot games.

In order to play, you buy “gold coins.” Gold coins are for entertainment only and don’t have any redeemable value. The casinos give you free sweepscash alongside this purchase. You use this to play slots and can swap any winnings for dollars and cash out to your bank account.

Sweepstakes is a popular model that works in most states. You can even get sweepscash for free. Chumba Casino gives players $2 simply for registering. Both casinos have promotions on social media and give you extra sweeps coins for mailing a letter, too.

Popular slot games

New slots are being created all the time. As technology improves, new formats, new gameplay and ever more immersive production become possible. Each generation of games sees classics emerge.

Here are some popular slots, which have stood the test of time:

• Electro-Mechanical: Classics include Wheel of Fortune, Top Dollar and Pinball. The three-reel format remains popular today, with some up-to-date games combining three-reel formats with interactive bonus games.
• Classic Video Slots: Early five-reel video slots that have remained popular include Ancient Egypt-themed Cleopatra range, TexasTea, QuickHits and Aristocrat’s Buffalo games. These classics are often updated, with new versions keeping the themes and adding new gameplay.
• Multimedia Slots: These days, slots often have themes around popular TV shows, movies and music stars. Popular games include the WalkingDead series, Michael Jackson-themed games and the Lord of the Rings.
• Slots with Huge Jackpots: The biggest jackpot slots you’ll find in casinos are the MegaBucks range in LasVegas. The prize pool for these is seeded at $10 million and often goes higher than that. Many casino slots around the country now have prizes above $1 million.
• Online Slots: There are thousands of online slots. Among them are casino slot games that have been adapted for online play. Most are created for online play by various studios. They include huge jackpot slots, including Mega Moolah and MegaFortune, plus classics like ThunderStruck II and Da Vinci Diamonds.

Slot bonus rounds and on-reel features

While the slots of the past were all about lining up those “7s” or bars, today’s games pay their biggest prizes via bonus features. Creative slot studios are coming up with entertaining variations of these games every month. They can include on-reel features, e.g., expanding wild symbols or separate bonus games.

Here are some of the types of bonus games to look out for:

• Wheel Bonuses: While mechanical wheels that tower above casino slots are still being produced, there are also electronic versions. The format started with the famous Wheel of Fortune games from IGT. These days, you can win jackpots and bonus features as well as cash prizes.
• Electro-Mechanical Slots with Bonus Games: Reel slots with picks games were early examples of innovation. These include Pinball and TopDollar, and basic pick games that use lights on the top section of the cabinet.
• Free Spins Bonuses: Many slots have free spins, which can come with multipliers, expanding reels, extra wild symbols and sometimes reveal systems. Retrigger your free spins and you could see those wins keep accumulating.
• Hold and Spin Bonuses: Pioneered by Aristocrat with their Lightning Link range, hold and spin swaps regular symbols for balls (in different designs), giving cash prizes and progressives. Each time you hit a new prize, you reset to three spins. There are now many variations of this concept.
• Jackpot Picks Games: Picking tiles or objects from screens for cash prizes or jackpots can be made into many entertaining bonus games. The standard system is to match three jackpots and win that prize. This system also decides what kind of bonus game you will receive.

Final thoughts

Slots are elaborate machines these days. Many have multiple on-reel features, impressive animations and second-screen bonus games.

When you strip away all the fancy features, slots work similarly. RNG software generates a string each time you hit spin, and this determines how the symbols land and how much you win or if you win at all. Returns are calibrated in advance to hit a specific percentage of the money put in.

RTP is usually between 90%-97%. Games are tested over millions of spins to ensure that the real returns match the percentage that is published. What is harder to judge is the variance of a game, which describes whether the payouts come in bigger though less frequent chunks or smaller (more regular) ones.

There are a lot of slots to choose from in live casinos and online. With plenty of competition between the studios to create the next big thing, those of us that enjoy these games can only benefit.

In the not-too-distant past, slot-machine players were the second-class citizens of casino customers. Jackpots were small, payout percentages were horrendous, and slot players just weren't eligible for the kind of complimentary bonuses -- free rooms, shows, meals -- commonly given to table players. But in the last few decades the face of the casino industry has changed. Nowadays more than 70 percent of casino revenues comes from slot machines, and in many jurisdictions, that figure tops 80 percent.

About 80 percent of first-time visitors to casinos head for the slots. It's easy -- just drop coins into the slot and push the button or pull the handle. Newcomers can find the personal interaction with dealers or other players at the tables intimidating -- slot players avoid that. And besides, the biggest, most lifestyle-changing jackpots in the casino are offered on the slots.

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The following article will tell you everything you need to know about slots, from the basics to various strategies. We'll start at square one, with a primer on how playing slot machines works.

How to Play

The most popular slots are penny and nickel video games along with quarter and dollar reel-spinning games, though there are video games in 2-cent, 10-cent, quarter, and dollar denominations and reel spinners up to $100. Most reel spinners take up to two or three coins at a time while video slots can take 45, 90, and even 500 credits at a time.

Nearly all slot machines are fitted with currency acceptors -- slide a bill into the slot, and the equivalent amount of credits is displayed on a meter. On reel-spinning slots, push a button marked 'play one credit' until you've reached the number of coins you wish to play. Then hit the 'spin reels' button, or pull the handle on those few slots that still have handles, or hit a button marked 'play max credits,' which will play the maximum coins allowed on that machine.

On video slots, push one button for the number of paylines you want to activate, and a second button for the number of credits wagered per line. One common configuration has nine paylines on which you can bet 1 to 5 credits. Video slots are also available with 5, 15, 20, 25, even 50 paylines, accepting up to 25 coins per line.

Many reel-spinning machines have a single payout line painted across the center of the glass in front of the reels. Others have three payout lines, even five payout lines, each corresponding to a coin played. The symbols that stop on a payout line determine whether a player wins. A common set of symbols might be cherries, bars, double bars (two bars stacked atop one another), triple bars, and sevens.

A single cherry on the payout line, for example, might pay back two coins; the player might get 10 coins for three of any bars (a mixture of bars, double bars, and triple bars), 30 for three single bars, 60 for three double bars, 120 for three triple bars, and the jackpot for three sevens. However, many of the stops on each reel will be blanks, and a combination that includes blanks pays nothing. Likewise, a seven is not any bar, so a combination such as bar-seven-double bar pays nothing.

Video slots typically have representations of five reels spinning on a video screen. Paylines not only run straight across the reels but also run in V's, upside down V's, and zigs and zags across the screen. Nearly all have at least five paylines, and most have more -- up to 50 lines by the mid-2000s.

In addition, video slots usually feature bonus rounds and 'scatter pays.' Designated symbols trigger a scatter pay if two, three, or more of them appear on the screen, even if they're not on the same payline.

Similarly, special symbols will trigger a bonus event. The bonus may take the form of a number of free spins, or the player may be presented with a 'second screen' bonus. An example of a second screen bonus comes in the long-popular WMS Gaming Slot 'Jackpot Party.' If three Party noisemakers appear on the video reels, the reels are replaced on the screen with a grid of packages in gift wrapping. The player touches the screen to open a package and collects a bonus payout. He or she may keep touching packages for more bonuses until one package finally reveals a 'pooper,' which ends the round. The popularity of such bonus rounds is why video slots have become the fastest growing casino game of the last decade.

When you hit a winning combination, winnings will be added to the credit meter. If you wish to collect the coins showing on the meter, hit the button marked 'Cash Out,' and on most machines, a bar-coded ticket will be printed out that can be redeemed for cash. In a few older machines, coins still drop into a tray.

Etiquette

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Many slot players pump money into two or more adjacent machines at a time, but if the casino is crowded and others are having difficulty finding places to play, limit yourself to one machine. As a practical matter, even in a light crowd, it's wise not to play more machines than you can watch over easily. Play too many and you could find yourself in the situation faced by the woman who was working up and down a row of six slots. She was dropping coins into machine number six while number one, on the aisle, was paying a jackpot. There was nothing she could do as a passerby scooped a handful of coins out of the first tray.

Sometimes players taking a break for the rest room will tip a chair against the machine, leave a coat on the chair, or leave some other sign that they'll be back. Take heed of these signs. A nasty confrontation could follow if you play a machine that has already been thus staked out.

Payouts

Payout percentages have risen since the casinos figured out it's more profitable to hold 5 percent of a dollar than 8 percent of a quarter or 10 percent of a nickel. In most of the country, slot players can figure on about a 93 percent payout percentage, though payouts in Nevada run higher. Las Vegas casinos usually offer the highest average payouts of all -- better than 95 percent. Keep in mind that these are long-term averages that will hold up over a sample of 100,000 to 300,000 pulls.

In the short term, anything can happen. It's not unusual to go 20 or 50 or more pulls without a single payout on a reel-spinning slot, though payouts are more frequent on video slots. Nor is it unusual for a machine to pay back 150 percent or more for several dozen pulls. But in the long run, the programmed percentages will hold up.

The change in slots has come in the computer age, with the development of the microprocessor. Earlier slot machines were mechanical, and if you knew the number of stops -- symbols or blank spaces that could stop on the payout line--on each reel, you could calculate the odds on hitting the top jackpot. If a machine had three reels, each with ten stops, and one symbol on each reel was for the jackpot, then three jackpot symbols would line up, on the average, once every 10310310 pulls, or 1,000 pulls.

On those machines, the big payoffs were $50 or $100--nothing like the big numbers slot players expect today. On systems that electronically link machines in several casinos, progressive jackpots reach millions of dollars.

The microprocessors driving today's machines are programmed with random-number generators that govern winning combinations. It no longer matters how many stops are on each reel. If we fitted that old three-reel, ten-stop machine with a microprocessor, we could put ten jackpot symbols on the first reel, ten on the second, and nine on the third, and still program the random-number generator so that three jackpot symbols lined up only once every 1,000 times, or 10,000 times. And on video slots, reel strips can be programmed to be as long as needed to make the odds of the game hit at a desired percentage. They are not constrained by a physical reel.

Each possible combination is assigned a number, or numbers. When the random-number generator receives a signal -- anything from a coin being dropped in to the handle being pulled -- it sets a number, and the reels stop on the corresponding combination.

Between signals, the random-number generator operates continuously, running through dozens of numbers per second. This has two practical effects for slot players. First, if you leave a machine, then see someone else hit a jackpot shortly thereafter, don't fret. To hit the same jackpot, you would have needed the same split-second timing as the winner. The odds are overwhelming that if you had stayed at the machine, you would not have hit the same combination.

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Second, because the combinations are random, or as close to random as is possible to set the program, the odds of hitting any particular combination are the same on every pull. If a machine is programmed to pay out its top jackpot, on the average, once every 10,000 pulls, your chances of hitting it are one in 10,000 on any given pull. If you've been standing there for days and have played 10,000 times, the odds on the next pull will still be one in 10,000. Those odds are long-term averages. In the short term, the machine could go 100,000 pulls without letting loose of the big one, or it could pay it out twice in a row.

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So, is there a way to ensure that you hit it big on a slot machine? Not really, but despite the overriding elements of chance, there are some strategies you can employ. We'll cover these in the next section.