The Complete Guide To Video Slot Machines

Ziv Chen

Updated by Ziv Chen


Last Updated 14th Mar 2024, 07:22 AM

The Complete Guide To Video Slot Machines

For many years, slot machine players were considered second-class citizens in casinos. They sat in the shadows of prestige casino table-game punters. That changed with the invention of the first video slot in the 1970s and later the launch of slot sites in the 1990s. Now video slots are the most popular game played in both land-based and online casinos.

Our slot experts at have written this comprehensive guide to video slots. It includes the history, types of games, mechanics, features, bonuses and everything you need to know about video slots. We’re constantly updating this page with new information, so bookmark it and visit us regularly to stay up to date on the latest video slots news, features and promotions.

What Are Video Slots and How They Work

Video slots are the most popular game played in today’s casinos. This includes both brick and mortar casinos with slots capturing over 80% of the casino’s floor space. Plus online casinos and online mobile slots where over 90% of all casino bets are wagered on the reels of video slots. However, this was not always the case. For many years, slot machines served as the backdrop to the card, roulette and dice game tables.

The History of Video Slots

To better understand what video slots are and how they work, it is worthwhile exploring their history.

There are many significant milestones in the history of video slots. However, the true revolution started in 1994 with the launch of the first online casino. This evolved into mobile casinos, which today let casino players all over the world have thousands of video slots at their fingertips.

It's worth noting that new slot games are being developed and released all the time. Our handy Slots Calendar has all the information you need to know about the latest and upcoming drops so you never miss out on the latest hit.

How Video Slots Work

Technology has revolutionized video slots and transformed the way we play them. But, many basic principles of slot machines are still the same – whether an old-fashioned One Arm Bandit or a state-of-the-art video slot.

Both slots with mechanical reels and digital slot machines will feature reels with different symbols. Where each symbol represents a different payout value. Every slot will have paylines which highlight winning combinations of symbols across the reels.

How to Play Video Slots

As this guide to video slots will highlight, there are many things to understand and keep in mind while spinning the reels. But the basic rules for playing video slots are quite simple. Once you placed your bets on a payline, press the spin button. Or pull the lever to spin the reels if you are feeling nostalgic. There are some video slots in the land-based casino that offer both options, with the lever being a memento for old time’s sake.

Once the reels stop spinning, you aim to align symbols with the pattern that is highlighted by the video slot’s payline. If the symbols align, you are awarded a win that is paid out with accordance to symbol value. If symbols do not land on a payline, you will forfeit your bet.

Note that slot machines have an RNG (Random Number Generator). This is an engine that regulates the slot and ensures that every spin has a random outcome. So although you can change your stake and bet on more or fewer paylines, there is nothing you can do to control or affect the spin’s outcome.

Video Slots Paylines, Reels and Symbols


As previously explained in this guide to video slots, a slot payline is a built-in pattern that symbols need to align with to generate a winning spin. Classic slot machines feature 1 payline which runs across the midsection of the reels and pays for symbols aligned from left to right.

The rise of video slots in the 1990s saw a new breed of slot machines. Which include 3, 4, 5 and even 25 and 40 paylines. Further changes now enable pay-both-way slots that will pay wins for symbols aligned from both-left-to-right and vice versa. There are many video slots with paylines that zigzag across the reels, and even a 1024-ways-to-win slot.

Having multiple paylines on a video slot brings the following benefits:

If you would like to bet on all the playlines, you can conveniently click on the Max Bet button which is available on most video slots.


The classic slot machines used to have a 3x3 game grid which shows 3 reels, each with 3 symbol positions. Technology advancement now allows game developers to feature multi-reel slots that are visually more attractive and provide more exciting gameplay. Plus, with many more chances to win. The most common video slot today is the 5-reel slot. However, there are also slot machines with 8 and more reels, as well as many more symbol positions. Some slots do not have any reels, but rather a grid of dynamic, floating symbols.

Video Slot Symbols

Beyond providing a visual spectacle that is key to the video slot’s theme, game symbols will determine the value of your win. The common game symbols include high and low-paying symbols, each having a different multiplier value that will be paid out against your stake. Winning spins can include different amounts of symbols (for example 2, 3 and 5 symbols aligned on a payline). Whereas more symbols will increase the payout multiplier.

Video Slot Special Symbols

Wild Symbols substitute for other symbols to help create winning combinations. This will usually exclude Scatter and other special and bonus symbols. Some video slots also have Expanding Wilds that grow to cover more spaces on each reel.

Scatter Symbols will either award bonus money or trigger a bonus round when landing on the reels. For example, 3 Scatter symbols will trigger a Free Spins session. On many video slot machines, a number of Scatter symbols will need to show on the reels at no specific pattern to trigger the bonus.

What are the Advantages of Playing Video Slots Online?

Before the times of online casinos, the only way to play video slots was by paying a visit to a brick-and-mortar casino. However, these days are gone, and now you can access thousands of the world’s best video slots from your computer or your mobile whether that's an Android or iPhone device.

Below are a few advantages of playing video slots online and on mobile:

Play from anywhere, at any timeOnline and mobile casinos give you the ultimate freedom to play video slots from wherever you are. You can play video slots on your couch at home, or on the bus on your way to work. 24 hours a day, 7 days a week, whenever you want to spin the reels.
Save time and moneyTravelling to the casino means planning a trip, taking time off work and paying for travel and accommodation. Your bankroll is already in the red before you even take your first spin. Playing video slots online doesn’t cost you any extras. Meaning you can spend a lot more time and money on the reels
Receive higher payoutsThis is the amount a slot machine will pay back in winnings over time. The average RTP in most land-based casinos is around 80% compared to an average 96% when playing video slots online.
Claim bonusesOnline casinos have intense competition. So they use generous slot bonuses to entice new players and reward the loyalty of returning punters. When playing video slots online you may be able to claim great bonuses such as sign up extras, deposit bonuses, free spins and other attractive offers.
Try video slots for FreeEither through bonus money, Free Spins or demo mode – online casinos allow you to test their video slots for free. This will let you research video slots that suit your personality and playing style. And playing for free will allow you to get acquainted with the bet limits, paylines, bonus features and gameplay.
Focus on your gameSlot halls in land-based casinos are a noisy place. There is constant chatter, announcements and hundreds of game tables and slot machines clinking. Playing video slots online lets you play quietly. You can concentrate on your game, immerse yourself in the visuals, and focus on your bets and winning strategy.
Enjoy a wide varietyBrick and mortar casinos are limited in floor space, meaning limited slot machine offerings. Moving from one slot machine to another involves getting up, grabbing your belongings and finding another game to play. Playing video slots online allows you to browse and choose from hundreds of video slots at just the click of a button.

What is the Random Number Generator for Video Slots?

The Random Number Generator (RNG) is the engine that will generate the combination of symbols that will appear after every spin once the reels stop turning. Video slots use a computer algorithm that makes sure that the outcome of every spin is completely random. Therefore the slot player cannot affect the outcome or predict wins based on a pattern.

Although each particular spin is random, the RNG regulates clever statistical models that are built into every video slot. These include volatility (also known as variance) which measures the level of risk of a slot. High volatility video slots will pay higher prizes less often, while low volatility slots will pay smaller prizes more frequently. An outcome of the volatility is the hit rate which determines the percentage of winning spins out of all spins. The RNG of a video slot also facilitates its Return to Player (RTP) which is the portion of total wagers that are returned to players in winnings. However this is a statistical payout over time, and the RNG will still generate random spin outcomes and not award wins to any specific player.

What are the Best Video Slots in 2021?

With thousands of video slots available, you are spoiled for choice. With different themes, features, mechanics, paylines, volatility, RTP and more. Visit our best slot games pages for hundreds of reviews of recommended video slots.

To get you started, we recommend a few of our favorites:

  • Gladiator - If you enjoyed watching Maximus fight in the hit movie, you will love this Playtech video slot. A low volatility slot with a progressive jackpot prize and bonus features.
  • Kiss - Spin the reels of the WMS medium volatility slot inspired by American rock band Kiss and legendary frontman Gene Simmons.
  • Divine Fortune Megaways - A Megaways remake of hit slot Divine Fortune brought to you by Swedish legendary game developer NetEnt.
  • Augustus - A Microgaming slot based on the theme of the Roman Empire. This medium volatility video slot offers a 96.14% RTP and potential win of 100,000x your stake.
  • The Mummy - This Playtech video slot unlocks the secrets of ancient Egypt. Based on Steven Summer’s 1999 blockbuster movie. This medium volatility slot features great graphics and sounds.
  • Siberian Storm - An ice-cool video slot machine by IGT featuring Siberian felines. A 96% RTP and a maximum win of 250,000x your stake.
  • CSI - Based on the drama and suspense of the American crime series. This IGT 5-reel, 25-payline slot offers medium volatility and 95.13% RTP.
  • Dracula - The vampire king starts in this NetEnt 40-payline video slot. It was made in collaboration with Universal Studios, and features a high 96.58% RTP.
  • Ghostbusters - An IGT 30-playline slot based on the big-screen hit from the 80s.

Tips on how to win on Video Slots

As the outcome of every spin is random, no system can guarantee you a win on video slots. As with every form of gambling, luck is a big component in winning. However there are a few things you can do that will help you pick the right slot, manage your budget and increase your chances of winning.

The following are a few tips for increasing your chances to win on video slots:

  • Find the right video slots: research slot games and find the ones that suit your strategy and playing style. Consider aspects such as volatility, RTP, bet limits, maximum win, etc.
  • Understand bonus features: Video slot bonus features such as Multipliers and Free Spins can increase your chances of winning considerably. It is best to understand how they work, what triggers them, potential returns, etc.
  • Play for free: Playing for free is a great way to research and try video slots. It will also help you understand the game mechanics, bets and features before starting to play for real money.
  • Use bonuses: Subject to wagering requirements, video slot wins from bonus money and free spins can be withdrawn and redeemed as cash. Shop for bonuses and use them to increase your betting stake. However, read the terms and conditions carefully to understand bonus rules.
  • Monitor your stake: Placing large bets on multiple paylines can potentially yield handsome wins. However, it can also wipe out your stake quickly. Manage your stake and remember that even if the video slot shows that you won, it can be less than your bet on the spin.
  • Make sure your bets quality: If you are playing progressive video slots, make sure that you place bets that are high enough to qualify for the jackpot prize you are playing for.
  • Set limits: Before starting to play every video slot session, set for yourself limits of time, bets and budget. This will include the total time of your session, the number of bets you are planning to place and the total money you are willing to spend. Once the time is up, you are out of bets or you lose the money you allocated, finish your video slot session.
  • Never chase losses: While winning on video slots is very exciting, remember that losing is also a big part of gambling. Never bet on money that you can’t afford to spend. Don’t try to win back your losses. As soon as you reach your budget or time limits, stop playing. This way you can come back again for what will hopefully be another fun and exciting video slot session.

Meet The Author

25 Years
Ziv Chen
Ziv Chen
Writer Writer

Ziv Chen has been working in the online gambling industry for over two decades in senior marketing and business development roles. Ziv writes about a wide range of topics including slot and table games, casino and sportsbook reviews, American sports news, betting odds and game predictions. Leading a life full of conflict, Ziv constantly struggles between his two greatest loves: American football and US soccer.

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