Understanding Online Slots: From RPT to Volatility and Everything in Between

Online slots have become a favourite among punters, offering endless entertainment through dynamic gameplay and striking visuals that cater to all tastes.

While slots can differ from each other in their themes or gameplay dynamics, most slots found in online casinos known to be a great choice for an overall slots experience will have some things in common.

To help you grasp these similarities and better understand slots in general, we’ve drafted this handy guidebook that cover the most basic concepts.

Slot Types

First off, you should probably know that there are various types of slots—not just an endless number of games with reels. Most slots can be distilled into four categories, with some possibly falling into multiple.

• Classic Slots – Classic slots are throwbacks to the golden days of fruit machines and one-arm bandits. These slots, which emulate the early games that took Vegas by storm, often have three reels, a small number of paylines, and symbols that are reminiscent of the good ol’ days.
• Video Slots – Much more common than classic slots, most slots (even those in other categories) are identified as video slots. They use stunning visualisations and animations, exciting sound effects, and often even have storylines. They also feature five or more reels and a higher number of paylines.
• Progressive Slots – Progressive jackpot games are like regular video slots, except all games share a central jackpot pool. Every player accessing the game adds to this pool, which can lead to exceptionally high jackpots. The most popular game in this category is Mega Moolah, which has turned many regular players into millionaires.
• Megaways Slots – Megaways is a unique game system that can be applied to video slots to increase the chances of winning. When this winning method is used, the game offers thousands (sometimes even hundreds of thousands) of ways to win.
• Other – Aside from the four categories listed above, cluster win slots and cascading reel slots are occasionally seen as two additional categories. However, these are more often seen as game features applied to slots in the above categories than as a type of slot on their own.

Slot Basics

Irrespective of the type of slot, every slot shares five basic features that are worth knowing.

• Reels – A reel is a vertical column in a slot that spins whenever you place a wager. Each slot reel holds a predetermined number of symbols, but the outcome of each spin is entirely random and controlled by the random number generator (mentioned below).
• Row – Working with reels, rows are the horizontal lines across a slot grid and lie across the reels. Rows typically determine wins, as a win must fall along a row to be counted.
• Paylines – Paylines are the invisible lines upon which specific or matching symbols must fall to achieve a win. In most classic slots, these fall directly on the rows of a slot grid. However, modern video slots may have paylines that run vertically, horizontally, diagonally, or even ones that form a zig-zag pattern across the grid.
• Symbols – Symbols are among the most important parts of a game. From the classic fruit and 7s to more modern, intricately crafted options, these are the images that are spun on a reel. Matching combinations of these images on a pay line results in a win.
• Paytable – A paytable is a chart that outlines what symbols must be matched to achieve a win and how much this win will be valued. As such, it is a good idea for players to study the paytable prior to playing to know which symbols to look out for and understand how much they will win if they manage to match them.

Additional Slot Factors

While the slot basics ensure that a slot is functional and easily understood by players, other factors are equally important to the fairness and usability of any game. Players should, however, be aware of these when choosing a game, as they can help determine their odds of winning.

The two most important factors are:

Return to Player (RTP) Rate

Many gamblers commonly refer to the RTP rate, although some may not understand it entirely, and plenty of myths surround it. Essentially, the return to player states the percentage of the money that a game receives that it is programmed to return to players in the form of winnings.

For example, if a slot has an RTP rate of 96%, for every £1,000 wagered in the game, £960 will be paid back.

It should be stressed that game developers calculate the RTP rate over millions of spins.

It is not a guarantee that, if you play £100 in a session, you will receive £96 in return!

A single jackpot won by one player could be offset by the cumulative losses of many.

Therefore, choosing a game with a high RTP may improve your odds, but it does not mean you’ll secure a win.

Volatility

Aside from RTP, a slot’s next most important factor is its volatility (also known as variance).

A volatility rating depicts how often a slot is likely to pay out winnings and how significant these winnings will be.

A slot can be assigned a high, medium, or low volatility rating.

• High volatility slots are known to grant winnings less often but often provide sizable amounts if a player is lucky enough to hit a win.
• Low volatility games are the inverse and offer more common wins but of a lower value.
• Medium volatility slots are those in between and provide a mid-range for win frequency and win amount.

Other Factors/Features

A few additional things to know about slots include:

• Bonus Rounds – These are rounds often triggered by achieving three or more of a specific symbol (called a scatter). During these rounds, none of your money will be used to wager, and you often have a heightened chance of winning.
• Free Spins – Free spins, as the name suggests, allow you to spin the reels without paying for the wager. These are the most common rewards for bonus rounds and are also often offered in online casino bonuses and promotions.
• Multipliers – Many games feature multipliers either as part of regular play or as a reward for entering a bonus round. These multipliers will be applied to any amount won and multiply the amount by the number of times the multiplier dictates. For example, £10 won with a 5x multiplier will result in a win of £50.