Slot machines, from fruit machines to the thousands of online video slots, owe their popularity to their randomisation and high potential returns from relatively low stakes. When you click on a slot, you know that you have the same shot as anyone at hitting a winning combination or even triggering the main feature.
The mechanism that allows for this, particularly in online slots, is the slot machine algorithm. More specifically, it’s the random number generation programmed into the slot machine algorithm. In equal parts, this element allows for suspenseful entertainment and for every player to get a fair shake.
Of course, a lot more goes into a slot game’s development than just producing random outcomes. Other factors like volatility, unique symbols and features, paylines and RTP need to be factored in as well. So here, let’s delve into the slot machine algorithm and uncover what powers these ever-popular casino games.
Basics of Slot Machine Algorithms
On the face of it, slot machines are very simple games. You spin the reels, the pictures fall into place, and if you get multiples of the same symbol in a line, you win. Still, for the games to be fair and enjoyable, work has to be put in to create randomness.
The more symbols there are, the more intricate the features. The mechanics of the games all require specific programming to produce unspecific results. Slot machine algorithms are now fully optimised to achieve all of this, and then some.
Random Number Generation (RNG)
Random number generation, or RNG, is at the heart of every slot machine algorithm. Whether it’s a video slot or a jackpot slot, it’s the random number generation within the algorithm that produces the on-screen results. When you press spin, the algorithm flickers through all of the possible combinations that can come from the symbols to produce a result for the player.
An integral part of the random number generation program is its lack of memory. It doesn’t store its results, nor does it follow a pattern or rhythm. As such, each result isn’t based on what came before. All spins are randomised from the point of pressing spin, regardless of whether the last spin was a big win or a loss.
Reels, Symbols, and Paylines
Slot machines don’t – or don’t often – spin numbers around the reels. So, the random number generation needs to be assigned to coded symbols and applied to the reels and paylines of the slot. Generally speaking, video slots feature five reels, three rows, a paytable of eight base game symbols and 20 paylines from left to right.
Usually, three of the same symbol on reels one, two and three need to land along a payline to produce a win. That win increases if another aligns on the fourth and fifth reel. In this example, any one symbol can have 60 ways to win and several other ways to lose. As such, there are thousands of potential outcomes – especially when you then include special symbols – for each RNG to have programmed in.
Pseudorandomness vs True Randomness
True randomness is what we can see in the world. We can see it in the wild with the random development of gene variants in biological beings, for example. What defines true randomness is its unpredictability and distinct lack of pattern, as far as we humans can tell. As such, a computer program, by design, cannot be truly random.
Instead, randomised results from an algorithm are examples of pseudo-randomness. The algorithm is based on distribution and, at some point, a human has instructed the program as to how to produce the results and selected a seed or a starting point. So, the process can be determined and repeated by those who can see the sequence. Still, for a slot’s gameplay, the results will appear to be randomised.
Components of Slot Machine Algorithms
A slot machine algorithm has many different components. Every element of the slot game needs to be programmed in, given meaning and even weighted within the algorithm. This way, the slot game can run as intended while also producing randomised results.
Low-paying symbols can hit more often, wins will occur to the predetermined variance, on average and bonus features can be made to be more impactful than the base game. The components, essentially, create the framework for the RNG to work within.
Symbol Mapping and Weighting
Online slots like Book of Dead, Big Bass Splash, Temple Tumble MEGAWAYS, and all others run on virtual reels. On each reel, there’ll be a set count and pattern for the symbols. What the symbol mapping achieves is giving each symbol a number that corresponds to the potential outcomes of the RNG.
This mapping allows for the low-paying base game symbols to have a higher chance of appearing through the randomised outcome than the high-paying ones. The mapping is a method of weighting symbols and outcomes. The outcomes are still randomised, but the chances of each appearing differ overall.
Paytable Design and Variability
Under fairness testing and regulations, payouts and the design of the paytable need to reflect the odds of winning. It’s because of this that more numerous symbols offer lower payouts than the more numerous ones. Paytables are a reflection of the RNG.
The results produced remain unbiased, but there will be more outcomes programmed in that are of the lower-paying variety. Programming in the paytable also allows developers to slide the number of potential winning outcomes to be more or less, weighted against the payout values.
When playing, this variability can be seen as the volatility or variance. If the paytable design makes it so that each combination tends to pay more, the number of outcomes that hit tend to make up a lower percentage of the range. So, they can play as high volatility slots like Gates of Olympus, where hits are less frequent, but the payouts are higher, on average.
Bonus Features Integration
Bonus features and special symbols must be programmed into the slot machine algorithm differently from the base game symbols. While some of the more modern physical fruit machines do have bonus features, digitalisation has allowed for far more complex features and different bonuses to come into play.
The developers need to make bonus-triggering symbols sparse enough to hold the increased value that they offer and to operate without the need to align on paylines – for the most part. So, scatters enter the algorithm as a different component. Wilds, while more common, are arguably more difficult to account for in the algorithm.
Some pay in their own lines, but all can play into any other base game symbol combination. Naturally, this adds more ways to win for low, medium and high-paying symbols. Slot machine algorithms need to account for this as even one wild symbol on each reel can alter what would be deemed the volatility and RTP of the game.
FAQs
Here are some more answers to many of the most frequently asked questions about slot machine algorithms and what could determine someone being more likely to win on a slot game.
Is There a Formula for Winning Slot Machines?
All slot machines are governed by a similar algorithm that, at the very least, gives a very strong impression of true randomness. As such, there isn’t a formula for winning slot machines, nor is there a formula for winning on slot machines. They’re as luck-based as possible in their gameplay.
Are Slots Completely Random?
Slots aren’t completely random because someone needs to program the slot machine algorithm. However, the algorithms are good enough at mimicking true randomness that, for anyone playing, the results are as good as random.
What is the Algorithm Behind the Slots?
The algorithm behind slot machines, which dictates the outcome of each spin, is a random number generator. Uniquely, these programs don’t have any kind of memory to halt repeat results or make others more likely due to a lack of hits.
Can Slots be Predicted?
Slots cannot be predicted. There are simply too many potential results on each spin to be able to accurately predict when a certain result will show. Furthermore, as the results are determined by a random number generator, there isn’t any true form of sequence to the results.
Is There a Secret to Hitting on Slot Machines?
There isn’t a secret to hitting on slot machines. Being wholly randomised games, you simply have to press the spin button at a point that the random number generator algorithm has itself landed on a winning combination. The more spins played or the run of misses in a row doesn’t necessarily increase the chances of the slot hitting on the next spin.
Which Slot Machines Have the Highest Hit Rate?
The slot machines that have the highest hit rate, on average, are those with low volatility programmed into the game. On average, low volatility slots payout more often than high volatility slots or medium volatility slots, but often in smaller amounts.
What is the Success Rate for Slot Machines?
The success rate for slot machines is partially determined by their volatility. Also known as variance, low-volatility slots produce successful results more often than high-volatility slots. However, high volatility slots tend to return more when they hit. Still, there isn’t a form of slot machine that doesn’t keep some of the money paid in for the house. This is determined by the return to player percentage (or RTP).
What Causes a Slot Machine to Win?
The slot machine’s random number generator algorithm causes it to win. For players, though, that’s only seen through the symbols that the reels land on. In this sense, what causes a slot machine to win is the reels landing with enough of the same symbol along any one of the paylines running across those reels.
Will a Slot Machine Pay Twice in a Row?
A slot machine can and sometimes will pay twice in a row. This would seemingly be far less frequent in physical slots compared to online slots, though. Online, there are more bets placed, and paytables can offer lower returns because the money is shown digitally rather than needing to be returned at that moment as hard cash.
What Time of Day is Optimal for Playing Slot Machines?
Online, there isn’t an optimal time for playing slot machines. Whenever you log in and click on a slot to play, your results will be held to the random results generated by the algorithm. At live casinos, playing on physical slot machines, there is a line of thinking that playing the games late at night or early in the morning can increase the chances of winning due to the influx of coins put in during the peak hours prior. Still, the results will be randomised.