Slot Game Mechanics And RNGs


  1. What Slot Machine Mechanics Used To Look Like
  2. How Today’s Slot Game Mechanics Differ
  3. How Does RNG Influence The Outcome Of Online Slots?
  4. Paylines And Paytables
  5. What Are 243-Ways Slot Games?
  6. The Rise Of Megaways

When you sit down to play slots online, very few of you will be aware of the technology involved in generating symbol combinations on the reels. You may also be unaware of how slot game mechanics influences your chances of winning when you click that all-important ‘Spin’ button.

Within this guide, we’ll explore the basic components of most successful video slots, as well as the advancements and innovations that have occurred since the creation of the world’s first mechanical slot machines.

What Slot Machine Mechanics Used to Look Like

You must go back as far as the 1890s for the creation of the world’s first coin-operated slot machine. Devised by American inventor Charles Fey in San Francisco, the Liberty Bell slot machine was the world’s first slot capable of triggering automated payouts when players landed winning symbol combinations on its three reels – each containing five drums (or symbols) apiece.

Each of the reels were imprinted with symbols such as spades, diamonds, hearts, horseshoes and the ‘jackpot’ symbol of a liberty bell. Once a player inserted a nickel into the slot machine and pulled the lever, the reels and their drums would begin to spin. Whenever all three reels would land on the liberty bell drum, the jackpot worth 50x the initial stake was automatically paid out. The outcome of these reels was totally random. It was influenced mechanically in some ways. Once the lever of a one-armed bandit slot machine was pulled a spring within the machine would contract. As the reels spun, the spring would gradually move inwards, eventually stopping the reels from spinning further.

As the popularity of land-based slot machines grew, some slot players began to devise ways to influence the outcome of mechanical slot reels. In the 1960s and early 70s, land-based mechanical slot games were tampered with using super-strong magnets. Players would subtly position a strong magnet next to the reels. The magnet was so strong that it essentially paralysed the internal springs and components, enabling the drums on the reels to flow continuously without being stopped. Once a player was happy with the position of the drums at any point – usually to generate a jackpot payout, the magnet was quickly removed and the drums locked into place.

Even more recently, a Big Bertha slot machine in Nevada was tampered with in the 1990s when a person climbed into the back of the machine to physically manipulate the outcome on the reels. Unfortunately for them, they were quickly discovered by the casino’s security and promptly arrested.

How Today’s Slot Game Mechanics Differ

One of the biggest differences between today’s land-based and online slot games is that they are programmed with predetermined payback percentages. These percentages are usually between 92 and 97%, known as the Return to Player (RTP), with the remaining 3-8% called the ‘house edge’ or the profit margin for the casino.

Many people struggle to understand how the latest slot games can have a preset payback percentage yet still have totally random spin outcomes on the reels. That’s because the expected payback percentage, also known as the return to player (RTP) percentage, is calculated over a vast volume of spins. We’re talking tens of thousands, even millions of spins of the same reels to achieve this RTP percentage.

What Does RNG Mean in Gaming?

To guarantee the random outcome of spins on online slots, casino operators rely on little microchips known as random number generators (RNGs) to take care of it. What is RNG technology? Put simply, an RNG is a microchip that is designed to continually generate number sequences, even when a slot game isn’t in play. These number sequences are generated fast – and by fast we mean superhuman speed, billions of times a second!

Randomness is key to all kinds of casino games. That’s why they are considered games of chance. It is through chance that you will win or lose a spin of the reels. Of course, there are some casino games where players can have some influence on its outcome. Take blackjack for instance, which has several strategies that players can adopt to maximise the RTP percentage over time. The reality is that while blackjack players can make smarter decisions using strategy, you still cannot guarantee a winning hand. The shuffling and dealing of cards is unpredictable – and so is the spinning of reels within a slot game.

How Does RNG Influence The Outcome Of Online Slots?

In the infancy of RNGs, casino players were sceptical about their legitimacy. There was a feeling that casinos were using RNGs to override the system and ensure there were more losers than winners on the reels. This could not be further from the truth.

In fact, the use of RNGs in slot mechanics has helped to create a fairer, more transparent industry for slot fans. The most reputable online casinos, including LiveRoulette, are periodically tested by third-party organisations, which examine the outcomes generated by the RNGs of slots and other table games. This ensures that players are getting the fairest possible experience on the reels.

Once activated, an RNG microchip will continually generate sequences of number combinations at break-neck speeds. Whenever a slot player hits that ‘Spin’ button, the RNG pauses at the same precise moment, locking in a sequence of numbers generated at random. Each number will relate to a symbol. These numbers are then fed into the online casino’s system to produce the relevant symbol outcomes on each reel. That’s about as technical as it needs to be for slot players, but hopefully, it’s an insight into how a spin of the reels really works.

Now you know the basics of RNG algorithms in slot gameplay, it’s important to know how the latest slot game developers create their games based around the RNGs. Slot developers vary the weighting of certain symbols, so that the probability of them appearing on the reels is more or less likely. Low-value symbols are be set to appear more frequently. Meanwhile, the probability of scatters or wilds landing on a payline may be reduced to get the right balance and generate an acceptable payback percentage, whilst paying out the big prizes from time to time.

Although RNGs help to create impartiality to the outcome of random slot game spins, it is possible for slot developers to influence the regularity with which players can hit winning combinations on the reels. The RNG itself has no ‘memory’ to speak of. It does not remember the outcome of the previous spin. However, slot developers program something known as a hit frequency into the RNG algorithm.

The hit frequency will determine how often a slot will form a winning payline on the reels. We’re not talking about how often a slot will trigger the maximum jackpot here, just how frequently a slot will pay out in any way, shape, or form. The industry standard for slot hit frequencies is around the 30% mark. However, it is not unusual for some low variance slots to have hit frequencies approaching the 40%-45% region.

Do bear in mind that hit frequencies are designed to act as a barometer of probability of landing a winning payline for individual slots. They don’t have a say in the size of the payouts. This means that short-run slot sessions have the potential to yield more frequent and larger returns than is statistically probable.

Speaking of short runs, it’s a good idea to touch upon the concept of short and long runs in the dynamics of slot gameplay. When it comes to short run gameplay, anything can happen on the reels. The longer run you have on the reels, the more likely it is that you will encounter results more closely aligned to the RTP percentage and hit frequency. In short run slot sessions of a small sample size of bets e.g. less than 100, there is always the potential for skewed results known as variance.

That’s why some slot experts recommend slot sessions to be for as few spins as possible, whilst playing the maximum available paylines for each spin to optimise your potential winnings if a successful symbol combination lands.

Paylines And Paytables

In the infancy of slot machines, going back as far as the Liberty Bell and many of the subsequent slot models, the games operated with a single payline across the middle of the reels.

This has been – and still is, the case with many three-reel mechanical and three-reel classic online slot games inspired by old-school fruit machine gameplay. The fact that you only have to keep your eyes peeled on one payline is a great starting point for today’s slot beginners.

As five-reel slot games have become the norm, the number of standard paylines on the reels has followed suit. Typically, they run horizontally along the reels and in triangular ‘V’ and chevron-like shapes. The shape of paylines has evolved further still into zig-zag formations up, down and across the reels, so much so that the newest slot releases available at LiveRoulette contain anything between 25 and 50.

As per a slot’s hit frequency, winning symbol combinations are equally likely to lock in place on any payline. Nevertheless, increasing the number of paylines gives slot developers another way to minimise a game’s volatility.

What Are 243-Ways Slot Games?

Some online slot developers have chosen to turn the concept of slot paylines on its head entirely through the launch of 243-ways video slots. In the conventional sense, no paylines exist behind the reels of a 243-ways slot. Instead of using symbols to create winning paylines, 243-ways slots pay out whenever at least three matching symbols land on adjacent reels from left to right.

Although the mathematics underpinning the 243-ways slot software may be rather more complex than this description, the result is that slot players can focus more closely on aligning the base game symbols together. Microgaming’s Immortal Romance is one such example of this type of slot.

The Rise Of MegawaysTM

If you thought 243-ways slot games were innovative, wait until we’ve explained the emergence of Megaways slot titles. At first glance, MegawaysTM slots look like most other state-of-the-art five-reel slots, except for the addition of a sixth reel. However, the mechanics of a MegawaysTM slot can change at the touch of a button, with a reel modifier capable of changing the number of symbols per reel for individual spins.

Some spins will give you five rows of symbols on six reels, while others will expand to give you the maximum seven rows of symbols on all six reels – giving you up to 117,649 ways to land matching symbol combinations, with not a single traditional payline in sight.

Today, MegawaysTM-powered slots come in all different themes, from light-hearted animal-themed slots through to hugely immersive slots inspired by ancient history. We’ve got plenty of titles to choose from, including couple of exclusive MegawaysTM slot titles in our portfolio – Megaways Respin and Desperados Wild Megaways.

In decades gone by, slot developers never thought it possible to magnify the number of ways to win on the reels to the magnitude that the MegawaysTM game engine has achieved. It’s an exciting thought that the next couple of decades could take online slot mechanics not just to new levels but a new stratosphere.

Ready to sample the latest video slots? Create your LiveRoulette account or log in to your existing account and explore slots with hundreds, if not thousands, of paylines available!

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