What Are Online Slots?
Online slots are chance-based online casino games that revolve around the concept of spinning reels with symbols and aligning these symbols in paylines. Paylines allow symbols to form winning combinations, which pay the player a certain amount of money based on how much they are betting and the value of the symbols lined up.
Online slots are based on classic slot machines. Most modern slots have left behind the classic 3x3 reel setup, as developers opt to provide players with more complex, feature-rich games that are more appealing to the modern gambler.
Recommended Online Slots: The Casino Wizard's Top Picks
We'll tell you all about online slots and how to play them with bonuses. First, though, we've made a list of popular and highly profitable games that every newcomer to the casino world must try out.
- Mega Moolah: Best for Multi-Million Payouts
- Book of 99: Best for High RTP
- Jokerizer: Best for High Volatility
- White Rabbit Megaways: Best High RTP Megaways Slot
- Starburst: Best Classic Video Slot to Play in 2024
|Where to Play
|88.12% (due to its jackpot)
|Book of 99
|White Rabbit Megaways
|Big Time Gaming
Types of Online Slots
Online casinos give us access to over 15,000 different online slot games. Although their themes, gameplay features, mechanics, and betting sizes vary significantly, they all fall within two categories: fixed-jackpot games and progressive jackpot slots.
Games that come with a jackpot that is determined by a multiplier. The total amount of money that you can win playing a fixed-jackpot slot is based on the size of your bets. For example, a game with a 2,000x jackpot and a max bet of $10 would be able to yield a max payout of $20,000.
Fixed-jackpot slots may also be affected by the max payout of an online casino, stated within the site’s terms and conditions. A fixed-jackpot game that pays out up to $1,000,000 in an online casino with a max payout of $300,000 would limit the total payout of the game to the casino’s imposed threshold.
Progressive Jackpot Slots
Slot games with a progressive jackpot build up the total amount of money that can be won in the game with the bets placed by users from all over the world. Network jackpots collect a percentage of the bets of all players and put them in a pool, which increases the total payouts of the game’s jackpots.
In most cases, these games come with 3 or 4 different jackpots. The largest jackpot is the hardest to win, but it usually yields prizes worth at least $100,000 (depending on the game and its popularity).
Basic Online Slot Mechanics
Online slots have an outline of basic mechanics that are present in every game, no matter how complex it may seem at first glance. These are some of the mechanics present in every online slot game, and what each of them does:
- Symbols: The core of an online slot. With them, you’ll make combinations in the game’s paylines, which give you a payout determined by the number of symbols in the payline and the size of your bet. Payouts are usually granted with combinations of at least three symbols, but some games pay low sums for two-symbol combos, too.
- Reels: Columns with symbols in an online slot. These spin when you click on the “play” button, and they’re where you’ll find the symbols in any game.
- Rows: Vertical “lines” in online slots. The more rows, the more symbols you’ll see in an online slot.
- Paylines: Possible paths or locations in which symbols need to be placed for a payout to happen. These are different from one slot to another. Generally, slots have a minimum of 10 paylines, but modern slots could have over 200,000.
- Bet Size: Amount of money that the player is betting per spin in an online slot game.
- Betting Range: Minimum and maximum allowed bets. Payouts are defined based on the size of the bet, and larger bets may offer better return rates in some online slots.
- Autoplay Features: Mechanics incorporated in online slots that allow you to play automatically, based on parameters you choose beforehand. You can add your desired bet size and the number of spins that you wish the game to play for you, and you can set up loss and win limits.
As well as basic mechanics, you’ll find four different types of symbols in any given slot game. These are the four ever-present symbols:
- Low-value symbols: Symbols that pay low amounts of money when a winning combination is formed. These are represented by card symbols like 9, 10, J, Q, K, and A, in most online slots.
- High-value symbols: Online slot symbols that generally follow each slot’s theme. They pay the most when a winning combination is formed with them.
- Wilds: Symbols that can substitute any other symbol, except scatters, to help create a winning combination. Most slots also allow you to form paylines with Wild symbols, granting out large payouts in return.
- Scatters: Symbols that don’t need to be in a payline to be activated. Most of the time, these symbols unlock access to a bonus feature and don’t offer a payout per se.
The way these symbols interact with one another, as well as the types of payouts and prizes that they unlock, wildly varies from one slot to another. This depends on the slot features that are present in each game.
Popular Online Slot Features
Online slots in modern casinos come with all different sorts of features that make each game feel unique. Some games mix many of these features to create an even more authentic experience. Let’s take a look at some of the online slot world’s most iconic and frequently found gameplay features.
Created by Big Time Gaming, Megaways slots come with over 100,000 paylines. Symbols occupy many different positions within slots, contrary to how they work in most casino games.
When a winning symbol combination is achieved in an online slot, symbols that are part of that combination will disappear, giving way to additional symbols that “tumble” from the top of the game and downwards, all within the same spin.
Reels that “extend”, giving room for more symbols or additional reels to appear when a certain combination is achieved.
Bonus Buy or Feature Buy
Games with the “Bonus Buy” feature allow you to pay a percentage of your bet to activate the bonus round of the game.
Games in which wins are paid when players manage to gather multiple symbols vertically or horizontally next to one another. Games with Cluster Pays don’t have traditional paylines, and usually come with reel setups of at least 5x5.
A feature that makes it possible for an additional symbol to appear in an online slot. These new symbols interact in different ways with existing symbols in the game, helping players create bigger win combinations or granting bigger payouts to existing combos.
Win Both Ways
Games with the “Win Both Ways” feature allow for paylines to be formed from right to left as well as from left to right.
Expanding Wilds or Symbols
Symbols that expand to cover an entire reel, or a big part of it. Expanding wilds allow players to create massive winning combinations, as they make an entire reel “wild”.
Sticky Wilds are wild symbols that remain in place for an additional spin, usually after a winning combination is achieved.
Shifting or “Moving” wilds make the wild symbols move from one reel to another, or change spots within the same reel, after achieving a winning combination or during bonus rounds.
Symbols that are “stacked” come in large groups of the same symbol within one of the game’s reels. You’ll see multiple of the same symbol in a row. This feature is generally present in games with a setup of at least 5x5 or within bonus rounds.
A feature that allows two or more reels to spin and show the same symbols in an online slot, allowing for large winning combinations between rounds. Synced Reels are activated after achieving a certain combination or as part of a bonus in an online slot game.
Created by NoLimit City, xFeatures like xWays, xNudge, and xBomb are exclusive mechanics found in their games that enhance your chances of winning.
A mechanic introduced in some slots (particularity in skill-based games) where players can choose one or more symbols and keep them in their place for the next spin.
Slot Glossary: Most Important Online Slot Concepts
Knowing the most common online slot terms is just as important to enhancing your online slot experience than understanding their most basic features. These are some key terms that’ll help you develop a strong understanding of online slot games:
RNG – Random Number Generator
Random Number Generators are used in online slot games to ensure that the outcome of each round is randomized. An RNG generates millions of numbers per second, and each number determines a specific position for the game’s reels. When you click on “spin” or “play”, a number is picked at random, and this determines the result of your spin.
RTP – Return to Player
The Return to Player rate is a percentage that represents how much money an online slot pays to players on average, based on the total bets placed. Slots have an average RTP of 96%, meaning that casinos expect to keep 4% of all bets as profit.
Slot volatility represents the variance of an online slot. High volatility means that payouts aren’t frequent, but big payouts are more likely. Lower volatility means that rounds that pay money will come more often, but they’re more likely to be small.
A percentage that reflects how many rounds come with payouts, on average. Some hits could give players a payout that is lower than the amount of their bet - especially when achieved with a a low-paying symbol.
Bonus games are minigames found within some online slot games. In these games, you’ll be able to collect special prizes like standard wins with multipliers, rounds with more wilds, or achieve higher payouts due to a larger presence of special game features like Stacked Wilds.
Bonus games can help you unlock a plethora of different features, such as:
- Free Spins: In-game free spins are given to played based on the value of their bet. If you enter a bonus game by betting $1 per spin, you’ll get free spins worth $1.
- Respins: Within most bonus games, you’ll be able to “retrigger” free spins, allowing you to restart the round or play with extra spins.
- Prize Drops: Bonus rounds tend to come with all sorts of bonus prizes. Some bonus rounds aren’t even based on spinning reels, but let you play pick-and-win games with growing rewards.
Bonuses to Play Online Slots for Free
One of the many advantages of online slots is that online casinos tend to design their bonuses to be spent in these games. As such, you’ll be able to spend almost any casino bonus to play slots for free, or play slots to unlock bonus cash that needs to have its wagering requirements fulfilled.
These are the most common casino bonuses that you can use to play online slot games on modern casino sites:
Sign-up bonus packages generally grant players a match deposit bonus of at least 100% plus a set number of free spins. Claiming a welcome bonus is usually the easiest way to get free spins that can be spent on popular games. The bonus cash obtained with one of these offers is usually able to be spent on slots, too.
No Deposit Bonuses
No deposit bonuses are free bonuses offered by online casinos, usually in the shape of a free chip or free spins. Free chips can usually be used to play bingo, keno, scratch cards, and slots. When offered as free spins, these bonuses are usually meant to be spent in a specific casino slot game. You’ll be told which game you can spend it on before claiming the offer, or during the claiming process.
A type of casino bonus that can only be used to play online slots or slot-like games. Free spins that you paid for (such as spins included in reload bonuses or sign-up deposit bonuses) are usually offered in packages of at least 100 spins, whilst no deposit bonus free spins are usually given in packages of 20 or less. Each spin represents a bet placed in an online slot, usually worth between $0.10 and $0.20.
How We Rank Online Slots
You'll notice that we give a different rating to every slot game that we review.
This isn't done arbitrarily, and it isn't a matter of personal preferences.
We consider a series of factors that help us determine the overall quality of an online slot, regardless of any mechanics that would be determined by personal preference:
- RTP: We consider how potentially profitable these slots are when judging and rating the best online slots real money casinos were offering. Some exceptions come into play, as is the case with progressive jackpot slots.
- Max Win: Each game's maximum payout plays a role in helping us determine how good a game is. Some modern slots come with payouts of more than 25,000x your bet.
- Betting Range: A low minimum bet and a large maximum bet make casino games accessible to all. This is an important factor during our rating process.
- Software Developer: Top casino slots are created by top casino slots developers; it's as simple as that. We consider how reliable and popular game developers were when rating these games;
- Game Features: In most cases, the presence of gameplay features such as in-game bonus rounds, free spins, and multipliers is a matter of personal preference. However, we determine how these features are implemented and how they work.
- Industry Influence: Some casino games have defined the industry and shot certain features to the iGaming world's mainstream. This is considered as well, as popular slots should be judged based on when they were released.
Pick a Slot, Find a Casino, and Spin the Reels Towards Glory
From fixed jackpot games with only wilds and scatters to modern Megaways slots packed with bonus features, online slots are as plentiful as their wide array of themes. Now that you’ve read this guide, you’re acquainted with how these games work, and you know why they’re so popular among casino players.
Pick a slot game from this page and see which casinos offer it, claim their no deposit bonuses (if available), and try your luck playing the game of your choice!
Frequently asked questions
Online casino slots are fair in the sense that you can win real money playing them, but the casino usually holds an edge of around 4% in every slot game.
RTP stands for “Return to Player” and represents the percentage of money that casinos expect to pay out based on the total bets placed in an online slot game.
Online slots are casino games with reels, rows, paylines, and symbols, that pay different amounts of money based on how many symbols players can align.
Yes, online casinos offer free chips and free spins that can be spent on different types of online slots. Most casinos only allow bonuses to be spent on fixed jackpot slot games.
- What Are Online Slots?
- Recommended Online Slots: The Casino Wizard's Top Picks
- Types of Online Slots
- Basic Online Slot Mechanics
- Popular Online Slot Features
- Slot Glossary: Most Important Online Slot Concepts
- Bonuses to Play Online Slots for Free
- How We Rank Online Slots
- Pick a Slot, Find a Casino, and Spin the Reels Towards Glory