Online Slots & Slot Games 2021

Slot machines have been a part of the gaming world since the 19th century, with the first of these devices being brought about in the late 1800s in New York. Since then, they have undergone evolution after evolution, going from the fruit machines of yesteryear all the way to the complex online slots that people have come to know and love today. Along the way, several innovations have taken place that have made casino slot games and online titles into what they are today. In this overview of online slots and slot games, find out what makes your favorite titles tick and what kinds of features you can expect from various online casino slot games. Players can also find out how slots work and how to win a fortune at online slots. Given the long history of this type of game, players will be fascinated by just how far the world of slots has come over the years.

Michael Tradford
Last Update:
September 15, 2021
This author was thoroughly tested and approved by the experts at before joining the editorial board to ensure a high content quality.
Author Bio:
Michael was Marketing Director in Atlantic City and worked in the casino industry for several years before shifting over to numerous newspapers in New York and Chicago working his way up to Editor-in-Chief. His focus areas are mainly in the fields of sports, gambling, and politics. He has a Marketing Degree, visited Columbia University during his time in New York and is now Editor-in-Chief at AmericaGambles.
Michael was Marketing Director in Atlantic City and worked in the casino industry for several years before shifting over to numerous newspapers in New York and Chicago working his way up to Editor-in-Chief. His focus areas are mainly in the fields of sports, gambling, and politics. He has a Marketing Degree, visited Columbia University during his time in New York and is now Editor-in-Chief at AmericaGambles.

Slot Machine: How it works

The first thing to understand when trying to figure out how to play online slots is how the actual slot machine works. A casino slot machine consists of a series of reels that spin to reveal a series of symbols on the reels, which are on a screen when playing online or in the cases of most physical casino games these days as well. When each reel shows its symbols after each spin, those symbols are run across a series of paylines. If a combination of symbols runs along a payline that is deemed worthy of a win, the player is paid out for that combination. There is a paytable available for all casino slot games that will show players ahead of time what paylines exist for each title and what symbol combinations will yield them money, to ensure fairness. Each game also has a return to player percentage, or RTP, that tells players what percentage of funds wagered they can expect to get back over the long term.

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The features of online slots

There are several key features that players should be aware of when they go to play a slot online.

Bonus games

When players land certain symbols, they may trigger a bonus game, which allows players the opportunity to play a brief standalone game that can provide them with a far higher payout than traditional slot spins. There are many different types of bonus games that players may encounter when they take to their favorite games.


Wild symbols can be substituted for other symbols throughout a slots game to form fortune winning combinations. The exception to this is usually special symbols such as those that generate bonuses or those that yield free spins. Wilds are usually one of the most sought after symbols in any slot title.


The scatter symbol can mean any number of things, from free spins to bonuses. But the basic idea behind the scatter is that they can lead to wins without having to fall along one specific payline. Instead, their appearance anywhere on the reels can be enough to trigger a win if enough of them are present.

Free spins

With each spin typically requiring a player to place a bet, it is always nice to get something for free. Free spins give players the chance to win a fortune on the slots without having to put down money out of their bankroll to wager on another spin. They are a risk-free way to earn more money from the bonus slots. If you want to play slots for free the demo versions on our website might be a good idea!

Nudge and win

Some players have looked back at slot spins and surely remember being just a symbol or two away from a huge win. With a nudge feature in some titles, players are able to alter reels by one or two spots, which could create the winning opportunities that they are looking for by changing the reels by just a bit.

Double or nothing

Some slot titles allow players the opportunity to risk what they have won on a given spin by playing a double or nothing game. These can take many forms, but the goal is to make a choice in a 50/50 type of game where a win would double the winnings from a spin and a loss would relinquish any winnings.


Depending on the rules of each title being played, some slots may offer a multiplier to players to boost the amount that they could end up with if they were to have success on a given spin. Some of these take place in bonus rounds, while others are offered during regular spins to boost the value players might see.

Tumbling and cascading reels

Tumbling and cascading reels bring an entirely new dimension to slot titles, where players have the chance to earn more. Winning symbols disappear after being paid out, making room for new symbols to fall into the screen where they can form additional combinations without a player needing to make another bet.


The goal of any slot player is to earn a jackpot. There are traditional jackpots, where a certain combination yields a maximum payout, and progressive jackpots where players’ bets add slight amounts to a jackpot that continues to increase until someone claims it.

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The different types of slots

There are several types of casino slot games, with these main game formats being the highlights.

  • Video slots: The most common form of online casino slots, video slots are the majority of what online slot players see today. They can feature any number of paylines and design elements to accompany what a player sees when they are spinning the reels, with very few limits to a developer’s creativity.
  • Fruit machines: The fruit machine goes back to the original slot machines, where the symbols consisted of fruits and bells and the number seven. Fruit machines are a name that is typically reserved for three-reel slots that don’t carry with them many of the special features that today’s more advanced video slots have to offer.
  • Adventure slots: For those who like to experience a bit of something out of the ordinary, adventure slots are a fun way to do just that. These titles see players embark on a journey rather than just spinning reels again and again, with characters involved in these titles and bonus rounds that do a nice job of breaking up the routine that some less sophisticated titles may fall into.
  • Jackpot slots: As if the name wasn’t self-explanatory enough, jackpot slots are games where players can earn a jackpot if things go their way on the reels. This genre of the game includes both standard jackpots and progressive jackpots, with players standing to earn big payouts from both forms of this exciting genre of game.

Popular slot themes

In addition to the above game types, there are several popular themes that players might see from their casino slots.

Movie-themed slots

Given the massive popularity of several movie franchises around the world, it only makes sense that there are plenty of slot titles that are modeled after some of our favorite films. These can include both new and old titles and how much the movies are integrated into the slots themselves depends on the developer and how well they integrate the movies.

Comic-themed slots

Comic books have become the inspiration for movies more than they are enjoyed as their own standalone form of entertainment these days. But that doesn’t mean that players can’t enjoy their subject matter in the form of Vegas slots are titles like Gonzo’s Quest and Eggomatic, along with music-themed efforts such as Guns N Roses and the Jimi Hendrix slot.

Video game-themed slots

Video games are naturally formatted into slot titles on a regular basis, as the popularity of both forms of gaming makes for a natural pairing. In a lot of cases, titles that are based around console or PC titles will utilize their licensing to create some interesting bonus levels or other types of interactive elements to make the overall experience of playing much more immersive than a typical casino offering. Some of these might be fantasy slots as well.

TV-themed slots

Television series have also lent themselves to the reels on many occasions, with some of the most popular shows in existence being turned into slots such as Game of Thrones or Sex and the City. These types of titles are often filled with symbols depicting beloved characters and items that are used throughout the respective shows. Some of these might belong into the category of "naked slots" as well.

Egyptian-themed slots

The use of Egyptian imagery throughout many casino titles is something that has become commonplace over the years, with the use of symbols like Cleopatra and the Sphinx frequently featuring. Given how strong the images from ancient Egypt are, it makes sense that developers often attempt to depict them while putting their own spin onto things.

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The most famous game developers

Behind some of the top titles in the slots industry are developers that have brought those titles to life. These developers in particular are known for providing titles that are memorable and give players some of the best experiences in the world of slot play.

  • BetSoft: BetSoft is a company that specializes in games with a 3D presentation, meaning that they have some of the top graphics in the entire online casino industry, just as NetEnt does. Some of this developer’s top titles include Gladiator and Dr. Jekyll and Mr. Hyde.
  • Konami: Konami was founded as more of an all-purpose gaming company than one that dealt specifically in slots. In fact, they are known for arcade and console gaming just as much as they are known for providing Vegas slots action to players. Some of their top slots titles include Chili Chili Fire and Sparkling Roses.
  • NextGen Gaming: NextGen Gaming is a company that was born in 1999, just as the internet was really starting to take off as something that could be used for gaming and finding information. As a result, this company has always been focused on play through the internet, which makes them perfect for the online slots industry. Some of their top titles include Andre the Giant and the Foxin Wins series.
  • WMS: WMS is short for Williams Interactive, who are responsible for some slot titles that are remarkably popular in the United States particularly. Titles such as the Bier Haus series and several Bruce Lee games have been created by this company, who have done an incredible job of developing games that American specifically have enjoyed.
  • Yggdrasil: Born in 2013, Yggdrasil is a part of the new wave of casino gaming that is focused entirely online. With a priority placed on high-quality graphics to go along with quality gameplay, new companies like this one have had to stay ahead of the curve. Some of the top titles that have been brought about by Yggdrasil include Beauty and the Beast, Wolf Hunters, and The Dark Joker Rises.
  • Novomatic: Novomatic was founded in 1980, with the company being something of a land-based slot provider often moreso than an online slot provider. But the online slot offerings provided by this brand are plenty strong in their own right. They include African Simba, Golden Planet, and the David Hasslehoff-based Hoffmania. This company acquired an online gaming company in the 2010s, which has allowed them a greater ability to introduce online titles.

Top five online casinos with slots

For those who want to find a slot game online, knowing where to look for casino slots is incredibly important. A quality slot casino should offer players hundreds of titles with a diverse array of game types and themes to keep them entertained. These sites in particular are worth checking out, as many of them have robust slot offerings that should be able to keep both new and experienced slot players entertained with their range of slot titles to choose from and the large number of different game types that they have to offer.

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Most common online slots questions

The legality of online casino slot games can vary from state to state. This is because different states have different law regarding wagering, including stances that could vary on playing a slot online. Players should look for their particular state law to make sure that they are able to play slots online.

Yes, online slots are both legitimate and fair. Respected online slots developers use a mechanism known as a Random Number Generator or something equivalent to ensure that the results of each slot spin are in fact random and cannot be influenced in an unfair way.

The amount that can be won in online slots depends on what kind of game is being played. Each title has a different maximum payout that players can find out before they start playing. And with some titles having progressive jackpots that continue to increase until they are claimed, there is no real limit to the possibilities.

While there is no way to guarantee victory at online slots, understanding how each game works and how each title differs from the others is a great way for a slots player to maximize their chances of a slot living up to their expectations.

Yes, many online slots are available to be played on mobile devices. And many online casinos now focus on delivering a quality mobile experience to their players to go with those compatible slots. Players should make sure that their preferred casino has mobile capabilities before they get started.


Online slots: An exciting way to play
As you can see, online casino slots are a lot more than just a bunch of pictures that pop up on a screen that may win a player some money. In fact, they are very intricate, with plenty to separate different types of games from each other and several criteria that determine if a player wins and how much a player can win. Now would be a great time to test your new slots knowledge by playing a slot game online. Check out the above slots sites to start your online slots journey now.
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