Slots Essentials: RTP, Volatility, Paylines and More

Slots Essentials: RTP, Volatility, Paylines and More

Online slots are the most popular casino games you’ll find today. They are responsible for around 30% of the global gaming market. However, before playing a slot game, you need to understand how it works. Our experts have compiled this extensive guide to show you the essentials of online slots, including volatility, RTP, pay lines, and more.

Random Number Generator

The random Number Generator, or RNG, is an important part of online slot machines. This essential mechanism ensures that the outcomes of slot games are completely random. The RNG makes sure that neither you nor the casino is able to determine or influence the gameplay outcome.

When you hit the spin button, the random number generator decides whether you win or lose. This is why we recommend playing games that feature an RNG that has been properly tested by certified testing companies. This is all the more reason to play only on tested and recommended casino sites.

Core Online Slot Mechanics

It is important to examine the core mechanics of slot games. Every slot game has reels, rows, paylines, and a paytable. Keep reading as we cover how these work.

Core Online Slot Mechanics

Reels and Rows

Reels and rows are present in all slot games and work alongside each other. The reels are the vertical columns consisting of symbols. Most slot games have five reels, but there are also three, six, or more reels. Once you place a wager and hit the spin button, the reels spin and show random symbols.

In contrast, the rows show the symbols in a horizontal arrangement. Regular slots have three rows of symbols at any time. However, there are games with four, five, or more rows, and classic slots stick to the basics with only one row.


Slot paylines remain in the background as you play the slot game. They only show up after landing matching symbols on the reels. Paylines are like rules that govern how you must land symbols on the reels to win and claim a payout.

There are different types of paylines in slots, including:

Single or Horizontal Paylines: You can find this mostly in classic slot games, and they run horizontally across the reels. To win a payout, you’ll need to match the symbols on this single line.

  • Vertical Paylines: These paylines run from the top of the reel to the bottom. In these types of slot games, you’ll need to land three or more matching symbols vertically on the reel.
  • Diagonal Paylines: Sometimes, paylines on online slots can run diagonally, starting from the top left corner of the reel to the bottom right corner of the reels. You’ll need to land matching symbols in this form to claim a win.
  • ZigZag: Some slot games have paylines that run from left to right in a W or V shape pattern on the reels.
  • Fixed Paylines: These slot games come with a fixed number of paylines that you can’t adjust. You’ll need to bet on all active paylines during each spin to win a payout.

Other Types of Paylines

In addition to the above, there are some other popular types of paylines, including those we’ll cover below.


If you’ve been gambling for a while, you’ll probably have come across slots with “Megaways” in front of its name. This means the slot game features the unique wheel setup developed by Big Time Gaming. It ensures that there is a different number of symbols per reel. Unlike your standard games, traditional Megaways titles can offer 243 up to 117,649 ways to win on each spin. Some of the best slot games we found here during our research include:

Slot Name and Provider Megaways
Bonanza Megaways by Big Time Gaming 117, 649 Paylines
Extra Chilli Megaways by Big Time Gaming 117, 649 Paylines
Danger High Voltage by Big Time Gaming 4, 096 Paylines
Blood Sucker Megaways by Red Tiger Gaming 117, 649 Paylines
Big Bad Wolf Megaways by Quickspin 117, 649 Paylines

However, this number has increased since Big Time Gaming started licensing the Megaways feature to other software providers. Now, you’ll find some Megaways slots having 15,635 paylines up to 248,832 winning ways. The outcome of every spin is different, with paylines changing on every round to ensure you have higher chances of winning.

Another popular type is slots with bonus features, which refresh your gameplay with innovative mechanics.

All Ways to Win

While most slot games will require you to land three symbols or more over a specific pattern of paylines, all ways slots do things differently. Here, you need to bet a fixed amount to cover all the paylines you can see on the screen.

You win if you land three or more matching symbols on the 1st, 2nd, or 3rd reels. To add more excitement to the game, all ways paylines slot games may include a combination of horizontal and diagonal lines. Avalon II by Microgaming is a great slot in this category we recommend you check out.  If you want to look at another game type, you can see if bonus-buy slots are something you might be interested in since they are some of the online gambler’s favorite titles.

Return to Player (RTP)

Another key mechanic of online slot games is the Return to Player rate. This shows you the average percentage of bets that a game will pay you when you win. So, if a game has a 98% RTP, you’ll get back $98 on every $100 bet.

All online slot games have a set RTP set by the software provider. This typically ranges from 88% to 99%. Online casinos will decide which types of slot games they want to offer on their platform. However, we recommend you stick with slot games with RTPs ranging from 96% to 99%. These will ensure you get more from any amount you wager in the long run.

Here are some of the high RTP games we recommend you check out:

Return to Player (RTP)

  1. Mega Joker by NetEnt – 99% RTP
  2. Blood Suckers by NetEnt – 98% RTP
  3. White Rabbit by Big Time Gaming – 97.72% RTP
  4. Starmania by Nextgen Gaming – 97.63% RTP


Volatility or Variance is another essential mechanism in slot games. It refers to the frequency at which a game pays out. A slot game could have either low, medium, or high volatility. Here’s a look at each of these and how they work.

Low Volatility

This means that you’ll get a payout more frequently, but they’ll come in relatively small amounts. Slot games in this category are ideal if you are on a budget. Some of the great options we found here include Da Vinci Diamonds by IGT and Starburst by NetEnt.

Medium Volatility

Indicates that the payout and hit rate come at a balanced rate. This is great if you want significant payouts at less significant risk. Gonzo’s Quest by NetEnt and Reactoonz by Play’n Go are great titles with medium variance for a balanced experience.

High Volatility

Slot games with high volatility will be hard to win but offer significant wins when you land them. You’ll need a huge bankroll since you may need to play for longer before you claim a win. If you love games that are high-risk but offer large rewards, then high-variance slots are your best bet. Great options in this category include Book of Dead by Play’ n Go and Bonanza Megaways by Big Time Gaming.

As you can see, the slot volatility influences how often you claim a payout, which is why we recommend you opt for a game with a volatility that aligns with your budget.

King’s Take: How to Use the Online Slot Essentials?

Understanding the essential mechanics of online slots is a great first step for any player who truly wants to boost his/her winning chances. This guide covers all the important areas, including RNG, RTP, Paylines, and more.

Once you have armed yourself with the information above, you can choose any of our must-try slot titles and start playing for a chance to win real money.