The Science Behind Slot Machines: Unlocking the Secrets of the Game

Online slots remain the cornerstone of online casinos, and the humble beginnings of the slot machine in 19th Century San Francisco has had a lasting impact on the gaming scene around the world. 

The modern slot games we play now are a far cry from the first mechanical machines that were found throughout the US in the early 20th Century, but without that innovative idea we wouldn’t have the huge range of online slots to play today with endless articles featuring slot tips and examples. Look at what’s on offer at Virgin Games, for example, and you’re guaranteed to find a dozen slot games that appeal to you. 

When you are pressing the button and spinning the reels, there is a lot going on in the background that you probably wouldn’t be aware of – but it is the science of the game that makes it work the way it does and makes it so much fun you want to keep coming back for more. In this article, we will look behind the scenes of your favourite slot games, and then give you some tips to make the most of every game you play. 

Behind the Screen

Graphics and Audio

Game design has come a long way, especially in the last decade or so. Pick up any console, and you’ll find sweeping, detailed landscapes, animation that moves in a wholly realistic way, and the smallest details in every scene rendered with near-realistic perfection. This is true in movies and TV shows too – and it has found it’s way into our slot games too. 

The innovation in graphics and design give us the crazy reel expansions, the fun cut scenes, and the bonus rounds, as well as making every part of the game shiny and colourful. Playing online slots at home now can make you feel like you are in a Vegas casino, or fully immerse you in the game that you are playing until nothing else exists. 


This little piece of algorithm is the true heart of the slot game – it controls which symbols appear on the reels, where the reels stop – and how often (and how much) you can win.

Random Number Generators (RNGs) are algorithms that are designed to ensure both fairness and unpredictability in slots. They start with a seed value, which might be derived from something like the date or the time. This starts the algorithm for each spin, and what is generated is a random sequence of numbers, which are then mapped to specific outcomes in the game. A number 2 in the third position on the algorithm might mean an orange is on the first payline, for example. 

These parameters and the seed value change to maintain unpredictability, and they are audited often to ensure that they remain random enough to be fair. 

It is worth noting that although RNGs are meant to be truly random, in fact they aren’t. Instead, they are random within certain boundaries, created to ensure that the RTP rate is consistent. The Return to Player (RTP) rate describes how likely you are to see a return on the game; presented as a percentage, it shows the proportion of deposits that are returned on average. The reason this is important to a player is that it gives an idea of how likely it is that you will get a win – the higher the percentage, the more goes back to the player. For the online casino, however, the RTP rate also determines the house edge – an RTP rate of 97% would give the house an edge of 3%. 

Top Tips

With slot games based on chance more than skill, there are a few things that you can do to make the most of the randomness. 

  1. Choose the right game. There are many different games, all with different rules – and the most important piece of information that you need to check out is the paytable. Here you will find the RTP rate, the volatility (the higher the risk, the higher the reward and the less likely it is to come in), and how to play. 
  2. Look for the bonuses. Certain symbols on the reels will have special meanings. These might be scatters that unlock free spins or a bonus game, or wilds that can replace symbols to create winning lines. Know what you are looking for to make the most out of this.
  3. Stake lower. While some of the prizes might be multipliers based on your stakes, using a lower stake is a less risky strategy that you can employ to get more spins. Staking it all on one stake is obviously a high-risk option, so hedge your bets a little. 

Know when to quit. Randomness means just that – and there is no magic number of spins that will land you the jackpot. If you are on a losing streak, don’t blow your bankroll – come back another time to play. Knowing when to stop – when it stops being fun – is key to success in slot gaming.

Author Profile

Michael P
Los Angeles based finance writer covering everything from crypto to the markets.

Leave a Reply