The Complete Guide to Slot Machine RNG

Every modern video slot is powered by a technology called Random Number Generator. RNG, for short. You can think of the RNG as the brain of a slot machine. Slot machine RNG is extremely important, as slots have to be fair and fun to play. In this article, we’ll take an in-depth look at the RNG, how it’s calculated and the most common myths and misconceptions. So keep reading to find out more!

What is Slot Machine RNG?

In land-based casinos, the random number generator was “calculated” using traditional methods - shuffling the cards, rolling the dice and sometimes flipping coins. The physical slot machines also used a more rudimentary system to determine the outcome of a spin. Providers took the number of slot symbols on every reel and divided them to get the probability on a single reel. Then, they multiplied by the other slot reels.

With the constant evolution of technology and the creation of video slots, a variation of this RNG system was needed. That’s because the quantities of numbers increased along with the number of reels and symbols. 

Online slots nowadays use what’s called a pseudorandom number generator (PRNG). This is an algorithm that comes up with huge strings of random numbers. However, the string itself is tied to a fixed number - the seed. Developers use this seed to determine the RTP (Return To Player) percentage of online slots.

Here’s a short and simple explanation to better understand how the slot machine RNG algorithm works:

• The RNG automatically creates streams of random numbers that are ready to be called upon at any time.

• When you click the SPIN button, the RNG chooses a random number.

• The number then determines the outcome of the spin. 

And that’s basically how the slot machine RNG works. It chooses random number strings that are then used to decide if your next spin is a winning one or not.

Slot Machine RNG Fundamentals

Using a random number generator allows the developers to set different values for every slot machine symbol. You can still see 8 symbols on a reel but the probability of landing them in winning combinations will vary. 

This means that now, slot machines are able to offer bigger prizes while still keeping a profitable edge for the casino.

Every number that the RNG algorithm goes through is associated with a specific combination of symbols on an active payline. Everything takes place in the backend, so you have no way of predicting slot machine RNG. 

In fact, you might even have two identical slot machines opened in different tabs that are programmed to give a different return to player percentage. The first slot machine might have an RTP of 70%, while the other might have an RTP of 98%. The only difference between these two slot machines is the probability with which the symbols might line up.

Programmed Randomness in Slot Machines

When we talked about what is RNG, we briefly touched upon PRNG. The main difference between the two is that RNG generates a random number, while PRNG uses an algorithm to create this number. So is it safe? Why do casinos use it if it’s not true RNG? Let’s take a look below at the differences.

• Unlike PRNG (which is powered by software), true RNG is powered by hardware. This has to be physically connected to the computer. These machines are manufactured by specialized companies and are incredibly complex.

• The true RNG machines are very slow. Much slower than PRNG. Because the latter is the fastest and easiest option to use, it’s the chosen one by online casinos. Every PRNG is completely different.

• The PRNG numbers are defined in advance and can’t be changed. From time to time, these numbers are replaced with random ones. This is done to provide better security against hackers. When these numbers are changed, the algorithm becomes impossible to predict or track down. 

How Does Modern PRNG work?

The outcome of every spin is decided in that milli-second it takes you to click the Spin button. The RNG slot machine is activated, selecting a series of numbers that correspond to a specific position on the slot machine reels. So even though the slot makes you think the outcome is decided at the last moment, the complete opposite happens.

Either way, the result of a spin is always random. And in case you were wondering, the result of the free spins is also determined in advance, as soon as you click the Spin button. Again, nothing wrong with that. The slot itself already knows the result, while you will have to wait until the end of the spin. This never means the slot is rigged. 

Slot Machine RNG, Hit Frequency and Payback Rate

Slot machine RNG, hit frequency and payback rate are closely tied together. But before we see how, let’s first define these terms.

Remember how we mentioned the seed? The seed is the fixed number that the algorithm string is tied to. Slot machine developers use this seed number to set the slot RTP. RNG algorithms are programmed to choose specific number combinations to get a consistent RTP percentage. Starting september 2016, all online casinos are required to monitor the actual RTP of the slots to make sure the RNG still works as intended.

They do that by dividing the total value of all slot payouts by the total turnover it has achieved. The end result should be as close to the initial RTP as possible. If it’s not, the slot itself is taken down while the RNG system is reviewed and fixed.

Because the slot itself is constantly creating new strings of numbers, the timing also matters. The outcome is still random, of course, but a split second could theoretically make the difference between a huge win and a loss. 

Slot Machine RNG and RTP

As we previously mentioned, RNGs are programmed to create and choose different number combinations. The average RTP percentage is calculated over 10,000 to 100,000 spins that are powered by the RNG behind. 

For example, a huge chunk of the online slots you’ll find have an RTP between 95% and 98%. The average is set at 96%. Generally, we don’t recommend playing slot machines that have an RTP lower than 95%. 

The top casino sites will always have a slot’s RTP displayed. Because it’s a very important and popular value in the iGaming industry, it needs to be out on display. Any provider that doesn’t mention the RTP of their slots is not trustworthy and should be avoided. 

How to Beat Slot Machine RNG

Now that you know all there is to know about how slot machine RNG works, it’s time we answer the age-old question: How to beat RNG in slot machine? While there’s no way you can guarantee a 100% win, there are some tricks that will help you increase your odds at landing a win. Let’s check them out!

• Play for longer with minimum bets. This is great advice especially for those players who don’t have a huge budget. To increase your chances at a win, you should engage in longer play sessions while only betting minimum. The more you play, the more chances you have to get a win. We recommend you play penny slots for free first.

• Play slots with fixed payouts. Slots with fixed max payouts are more reliable than progressives, for example. So if you’re trying to predict the outcome of a spin (to a point), you’re better off avoiding progressives. They’re notorious for their incredibly high volatility and rather low RTP.

• Play three-reels slots with few paylines. When you play slot machines for real cash, it’s better you start off with simpler slots. The three-reels slots with fewer paylines are the perfect choice for the gamblers who want to have a certain degree of control over the game session. 

• Study the paytable. Video slots have many different symbols and features that might be confusing for a newcomer. So before you place your bets, check the paytable and understand what every symbol pays out. Depending on how many special icons and symbols a slot has, the more (or less) likely it is to pay out.

• Play slots with a high payout rate. The higher the payout rate (RTP), the higher your chances at a win. While these slots are still based on RNG, they will award some good wins more often than the rest. Here’s a list of casino slots best payout that you can find on SlotsMate:

  • Beat the Bank by WGS: 99.17% RTP

  • Ugga Bugga by Playtech: 99.07% RTP

  • Mega Joker by NetEnt: 99% RTP

  • Cosmic Quest: Mystery Planets by Rival: 98.9% RTP

  • Crystal Clear by Realistic Games: 98.7% RTP

Does Understanding Slot Machine RNG Make You a Better Player?

In short, yes and no. When you know what is RNG in gaming, you have a better understanding about the game’s mechanics and how everything works in the back-end. Naturally, when you know everything about a machine, it will be easier to increase your odds. 

However, this doesn’t necessarily make you a better player. Sure, you have some extra knowledge but that doesn’t mean you can use it to influence the slot itself. So at the end of the day, your odds at winning are equal to a player who doesn’t understand RNG. 

Our Conclusion

Now that you know what is slot RNG based on, you’re more than ready to take full control over your gambling sessions. We’re sure that while you play slot games with bonus features, you’ll considerably increase your odds at a win. Just keep in mind that in online slots, there’s no such thing as a loose machine, so you can’t accurately predict the outcome of every spin.