Online Slots Explained

Are you new to online slot games? Learn everything about these exciting games, including how they work, popular types, unique bonus features, payout percentages, top providers, compatibility, and much more, in our comprehensive guide.

Online casino gambling is on the rise across the US states. Numerous online casinos offer different types of games in free mode and real money. Online slots are the most popular games you can find at any casino site. They are liked by many people because of the simple gameplay, innovative themes, lucrative bonus features, and high payout percentages. Also, these games are playable across all devices, including smartphones, tablets, and desktop computers.

Whether you are a beginner or a veteran player looking for extra knowledge about online slots, we've provided helpful information to guide you through. You'll learn about online slot mechanics, popular types of slots, unique slot game features, and much more.

A Brief History of Online Slots Games

Slot machines have been around since the invention of the first casinos. They were among the first games to hit casino floors even before the online casinos were invented. The history of these games stretches back to the implementation of the Free Trade and Processing Act in Antigua and Barbuda more than 25 years ago. It was from this moment that people received licenses from companies to offer online casino games.

The first renowned slot developer was Charles Fay, who dominated the better part of the industry from 1895 to 1964. It was not until 1964 that the first electronic slot machines gained popularity in the US.

New technological advancements lead to the evolution of slot machines. The first online slots hit the market in the 1960s. Though the number of games was limited, they spread widely across the globe. The original online slots were identical to the classic single-reeled fruit machines.

The latest online slots are packed with exciting bonus features, massive paylines, and exclusive bonus features to enhance your winning opportunities. While playing slots is legal in most countries, you can only play real money slot machines in legalized states in the United States.

How Online Slots Work

One of the significant advantages of slot machines is the simple gameplay. Unlike table games, slots don't require special skills or an optimal strategy to play and win. Moreover, you don't have to dress up in your official attire to play. These games are optimized using the latest cutting-edge technology to fit all devices, including mobile and PCs.

The thumb rule of online slots is to match at least three or more symbols on active paylines to win. All winnings are awarded starting from the leftmost reel to the rightmost reel, and they are completely random. The payout rate and chances of winning an online slot vary depending on the game and provider.

Nevertheless, the rule applies across all types of slots. Another thing you should understand is that the betting range and bonus features vary from one slot machine to another.

Additionally, all online slots are built with Random Number Generators (RNG) that help determine the payouts. The RNG software in slot machines works by ensuring all winning spins are randomly generated. Also, the software is audited and certified by an independent authority to ensure it's not biased. Therefore, all payouts are fair and randomly generated.

Different Types of Online Slots Games

As earlier mentioned, there are different types of online slot machine games at top US online casinos. These games are reminiscent of the original traditional fruit machines despite the difference in designs. 

These are the most popular types of slot games you can find at online casinos in the US:

3-Reeled Slots

Classic or 3-reeled slots are the most popular types in online casinos. These slots are considered the simplest of them as they don't have many features. Classic slots are sometimes referred to as one-armed bandits because they resemble the traditional fruit machines. The themes, symbols, and design of these games will give you a true Las Vegas experience. The best thing about classic slots is they have progressive jackpots with life-changing rewards. Many punters opt for classic slots because they as faster, easy to learn, and easy to play regardless of your experience or budget.

5-Reeled Slots

Most modern online casinos have moved from offering classic slots to five-reeled or video slots. These slots are the most common at US online casinos and globally. The appealing thing about video slots is stunning graphics and immersive sound effects. Additionally, video slots have more bonus features and paylines that increase your odds of winning. What sets these games apart from classic slots is the diverse mechanic, such as multipliers.

Progressive Slots

Progressive jackpot slots are the most sought-after games for obvious reasons. They offer bigger payouts than standard slots. The good thing about these games is that the jackpot keeps increasing with every bet. Most online casinos display the accumulated amount of the jackpot for everyone to see. Progressive slot machine games are connected to different casinos and can be won randomly by any player. The maximum prize pool can increase up to millions of dollars depending on the provider.

Interactive Slots (i-Slots)

Interactive slots are more exciting to play than regular games. What makes these slots unique is they have free games and a bonus. They have mini-games that allow players to multiply their winnings. Even more exciting is that players can wager on miniature golf in the bonus rounds. The best part is that iSlots don't entirely depend on chance like regular games.

Virtual Reality Slots (VR Slots)

Today, you can find a wide collection of online slots games to play at VR casinos. Unlike your ordinary games, these types require special equipment, including a headgear, to play. Many VR google brands are available, including Oculus Rift, Samsung R, Sony Play Station, and Razer OSVR.

3-D Slots

Three-dimensional slots or 3-D slots are more detailed than an average slot machine. Though these games are similar to video slots, they have impressive graphics and 3-D characters that are more engaging. You can find highly entertaining and unique slots at top online casinos in the US.

Mega Spin Slots

If you feel like one type of slot is insufficient, you can opt for Mega Spin games. You can play different slot machines on the same screen simultaneously. However, these games require you to have a bigger bankroll, and the payouts are worth it. The rules and other basics of Mega Spin slots are the same as regular slot machines.

Online Slot Games Features

Online slot machines have come a long way from the 1-reeled coin machines to the latest video slots. These games are developed by different companies and come with varying special features to increase your winning potential. The biggest battle among developers is creating games that are as catching and engaging as possible. The following are the most common features you find when you play online slots:

  • Free Spins Round: Free spins provide you with a number of free spins to increase your winning opportunities. Free spins can be activated differently, such as when you land scatters. Also, the number of spins varies from one game to another.
  • Bonus Games: Bonus games are offered in different forms, and they provide a good chance to win extra money. The way to trigger bonus games is by lining up specific symbols on the reels.
  • Wild Symbol: Wild symbols are common in classic fruit machines and modern slot machines. This symbol substitutes for all other icons on the reels to form winning combinations. The most popular types of wilds are expanding wilds, transferring wilds, sticky wilds, stacked wilds, and random wilds.
  • Retriggering: With the triggering feature, you get the chance to re-play your bet for free. Retriggering can happen several times in a slot machine.
  • Scatter Symbol: The overall rule of playing slot machines is that you must match symbols on paylines to win. The scatter symbols go against this rule as they pay anywhere in the game.
  • Multipliers: Multipliers, as the name suggests, increase your payout by doubling your stake. The multiplier will range from 2x and can go up to 5x your stake.
  • Win Both Ways: Slots with win both ways feature as the best because they pay starting from left to right and right to left. This creates more winning opportunities than one-way slots.
  • Progressive Jackpot: Progressive jackpot games are popular in land-based and online casinos. These games are connected to different casinos, and they offer significantly bigger payouts.
  • Paylines: A payline is a row when winning combinations are formed. The number of paylines will vary in slot machines. Some are limited to a few lines, while others have massive paylines.
  • Pay Tables: Every online slot game has a unique pay table that shows payouts for certain combinations. The pay tables provide information about the wild symbols, scatter symbols, and other special features of the game.
  • Auto Spin: Most games have the Autoplay or auto spin feature. Once this feature is activated, the game will help spin automatically without interruption.

Top-Notch Online Slot Machine Developers

Online slot games are created by different software companies. These developers utilize the latest cutting-edge technology to deliver unique games with all the exciting features to enhance your gameplay. Moreover, the number of providers and games varies depending on the sites you choose. The following are the most popular online slot creators:

  • NetEnt
  • Microgaming
  • Big Time Gaming
  • Yggdrasil
  • Betsoft
  • Playtech
  • IGT
  • Bally Technologies

Online Slots Terminologies

Online slots have different terminologies you must learn before playing for real money. The following are common terminologies:

Credits: The money you use to wager on online slot machines.

Freeplay: Slot games that can be played without depositing any real money.

Symbols: Icons used to form winning combinations in a slot machine.

Pay Table: A table indicating the symbols and the possible payouts they offer.

Payline: This is an active line in a game that determines the combination of symbols.

RNG: The Random Number Generator is a computer program used to determine fairness in slot games.

RTP: Return to Player (RTP) percentage is what the player profits from a slot in the long run.

Volatility: Volatility or variance indicates how often a certain slot game pays. It could be low, medium, or high variance.

Online Slots Winning Tips and Strategies

Winning at online slot machines is not a big challenge as the games are entirely based on luck. The good news is that there are ways you can follow to maximize your winning opportunities when playing slots online. Here are the tips you can use to win more:

  1. Always set a budget before you start playing real money slots.
  2. Do your research about the game to know the variance, RTP, and other features.
  3. Never chase your losses.
  4. Pick an online casino with generous bonuses.
  5. Choose online slots with the highest RTP.
  6. Learn how to manage your bankroll.
  7. Take your time to learn and understand how the game work.


Slots are among the favorite games in online and land-based casinos. Many people, including beginners and professional gamblers, enjoy the thrill and fun that come alongside these games. We hope that our comprehensive guide has expanded your knowledge of online slot games. We highly recommend finding a licensed and regulated online casino to play slots.


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