Slot RNG, PRNG & Randomness

Slots are random thanks to algorithms called pseudo-random number generators. Learn how do slot hacks happen and how random slots are.

Incredibly high payouts, bet multipliers, and rare progressive jackpots are sitting behind a random number generator (RNG) of a slot game.

Are slots RNG designed to keep the house winning or is there a chance to beat it? Let us answer that question in this article. Please switch on your mathematical brain, as this is a huge part of randomness in slots.

What Is a Slot's Random Number Generator

RNG is a means to create a random result from a set of numbers. Dice are one of the classic RNG tools with a six-sided die giving you a result ranging from 1 to 6. Other ways to create random results are a deck of cards as well as a two-sided coin.

How do slot machines incorporate random number generation (RNG) into their mechanism? It comes down to true or pseudo-random numbers. True RNG consists of vintage or mechanical slot machines while the latter makes up all digital or online slot games.

True Random Number Generators

Imagine rolling a six-sided die and it lands on 3. Calculating the probability of the result will likely consider one of six sides to land on top, which means there is a 16% chance of us getting a three.

In the real world, there are many factors involved when computing the probability of an actual dice's result. Factors such as the wind direction, flatness of the surface, angle of throw, and much more come into mind when calculating the results. True random number generators take into account natural entropy or "actual randomness" into the equation.

Roulette is a good example of true number generators used in the gambling industry. As the ball spins around the wheel, the exposure of the ball to natural entropy such as the roughness of the material or ambient temperature of the room contributes to the results.  

Pseudo Random Number Generators

Unlike true RNG, pseudo RNG is not affected by natural entropy. To compensate for the lack of entropy and to simulate authentic randomness, PRNG results come from a short initial value going through a complex equation. Using the seed value or key, PRNG games create a random sequence that does not have any predictable patterns.  

While computer-generated seeds are efficient in producing random slot results, it is still not actual "randomness" since the algorithms are based on digital simulations. On the other hand, PRNG is a cost-efficient way for software providers and slot machine manufacturers to recreate authentic random results.

How Do Slot RNG Work

With the two different RNG method, how does this apply to slots games? What computations go on behind the computer screen or cabinet each time you click or press the spin button?


Seeds or keys determine the digital random slots result and are the base value of PRNG algorithms. When you spin the reels, the slot machine generator uses a seed in a long complex equation to determine which symbols will appear on the pay lines.

Take note that despite the complex equations, every slot seed number creates the same results. Programmers and developers require every seed to generate its respective result to find and fix/debug errors in the program. On the other hand, one seed can generate more than one random result to simulate natural entropy.

With randomness in mind, how does the slot machine RNG algorithm picks its seed?  A common factor is the system clock among PRNG algorithms to generate a seed. While there are other ways for a PRNG among slot machine algorithm to select is a seed, it is set in a way that creates unpredictable results.


Actual randomness or entropy allows for authentic results. Incorporating entropy ensure every spin gives you a real probability of matching five high-paying symbols or clearing the jackpot condition.

Expanding on the answer as to where the seed for the PRNG sequence comes from, programs use "simulated entropy" to create a random key for the algorithm. Apart from the system clock, sources of entropy include mouse movement, clicks, and keystroke rates. Entropy is required when it comes to using PRNG for security since predictable algorithms can open the door to illegal exploits.

While online slots do not have access to physical hardware to create results with natural entropy, programs can utilize cryptographic hash functions to generate unpredictable results such as SHA-1 or MD6. In the case of slot software providers, their methods on how they create their random numbers are confidential from anyone.

Physical Generation Methods

An easier way of explaining the physical generation of random numbers is to imagine a dice roll or coin flip. Natural entropy and manual exertion have a hand over the results of this method. Classic or vintage slot machines use this method by having a braking mechanism on their reels.

Incorporating natural entropy to slot RNG is not yet possible until the creation of quantum computing. Instead, the algorithm looks for factors creating unpredictable results based on quantum mechanics laws. Some of the occurring entropy within computer hardware includes radioactive decay, shot noise, and thermal noise, which can be used to create random results. One notable example of a program using physical generation method is, which uses atmospheric noise to create random results.

The closest way for online slots to achieve natural entropy is to use cryptographic hash functions. While it is not close to using quantum mechanics laws, this method can closely recreate physical generation methods result.

Computational Generation Methods

Online slots use computer-generated results to determine the payout results of each spin. PRNG is the common computer generation method used by gambling games that creates unpredictable results with a seed or base value.

An example of simulated randomness can even be achieved on paper through the middle square method from John von Neumann. For computer languages such as PHP, Python, and Ruby, its common way to generate results is the PRNG method of Mersenne Twister that can create "statistical" randomness.

When it comes to slots, more complicated and long equations are needed for its computation generation algorithm. Slots use a method to create random number sequences instead of just random numbers. With a sequential number results translation on the symbols, every reel combination has the percentage of hitting the pay line.

PRNG with a random number sequence used for slot games can be tested with the Chi-Squared Test. If the PRNG calculation is well within the Goodness of Fit parameters, the algorithm can generate unpredictable results.

How to Beat a Slot RNG

Forget the movies, there is no slot machine RNG crack or exploit. Nearly every online slot PRNG on all popular casinos has an unpredictable pattern. Players cannot influence the seed or results by setting a specific bet amount or hitting the spin/auto spin button in a certain sequence.

With that in mind, are slot RNG rigged for the house to win? Is it possible to beat random number generators in slot machines?

How to beat a slot PRNG

Slot RNG Timing

System clocks are the most common source of seeds or keys among slot PRNG algorithms. Every seed will always create the same sequence of numbers or a symbol showing on a pay line in each reel. With RNG timing in mind, can people find a pattern and take advantage of it? Surprisingly, RNG attackers found a way to see this pattern on physical slot machines.

RNG timing attackers will capture a video clip of the slot and transmit it to a phone app, which tabulates the times and sequence of the slot. With the information on the sequence at hand, cheaters can hit the spin button when the seed is set for a massive payout.

Take note that you do not have to go the extreme by using a special app or program to find the right pattern. Instead, you just need to keep playing a specific game as much as possible. Keeping the bet close to the minimum amount is also recommended to help you keep playing longer.

Continuous playing is much like setting a wide net onto the ocean to catch a fish. Given the probability of playing numerous times, you increase your chances of hitting a seed that gives the best possible payout in the game.

Non-Uniform RNG Distribution

Results of every slot machine among major casinos always achieve non-uniform RNG distribution of numbers, which are nearly impossible to predict. With a complex algorithm, digital slots RNG achieve nearly the same random results generated by mechanical or vintage slots.  

No one can control the seed or RNG algorithm of nearly every slot game. What if there is a way you can limit the non-uniform RNG distribution to help you see a pattern in the slot games? You can achieve this by playing on slots with three reels as well as a few pay lines and symbols.

Playing on limited reels is much like playing a game of concentration or matching face down cards with a quarter of a deck. Five reel slots and ones with progressive jackpot usually have a staggering amount of numbered sequence that makes them nearly unpredictable.

How Random Are Slots?

Random slots result should be set in a way that every player has a chance to win a life-changing fortune. How can you tell if an online slot game produces random results?

Prominent software providers assure all players that their slots generate random results by having their game tested through a third party company. iTech labs is one of the recognizable RNG testers that checks the predictability, statistical randomness, internal state of the RNG, and non-repeatability of the algorithm.

You can make sure an online slot game has its RNG certified by visiting the software provider's website and check on their licenses and certification. If you visit GameArt for example, you can find that their slots are Gaming Labs Certified.

What RNG Mean For Slot Players

Certified online slot games are set to create randomize results with its complex algorithm. Players are the ones who benefit the most from the complete randomness of slots.

Imagine playing a slot machine that has a predictable pattern of reels. People will flock towards that game and will keep playing just for the sake of profit instead of enjoyment. Another scenario would have casinos manipulating the slot games to give the impression a player is close to winning but is influencing them to keep spending money.

Randomness is what makes slots enjoyable for any casino player. You can always feel the authentic thrill of matching those high-payout symbols or entering a bonus game because that probability is achievable.

Respected regulation offices such as the Malta Gaming Authority make sure its licensed operators are always offering actual RNG with its slots. You can always use the license or certification of a casino and online provider to know that you are getting the real casino experience.

Slot RNG & Randomness FAQ

Our answers to common questions about slot randomness and slot random number generation.

How fast do RNG in slot machines work?

Slots RNG can run its algorithm to create a random result every millisecond. Calculations keep occurring even when no one is hitting the spin button. By the time you clicked on the button, the program already knows the outcome of the reels.

Do online slots use an RNG?

For any online slots to determine what symbols appear on the pay lines, it uses an RNG algorithm to create a random result. Online slots RNG generates these results by having a seed or base value go through its complex algorithm.

How do slot machines use RNG?

Every slot results come from the generation of a random number sequence apart from just a number to create unpredictable outcomes. Each symbol corresponds to the sequence, allowing every symbol combination to have a fair possibility of appearing on the pay line.

How to time an RNG on a slot machine?

Each slot's seed is generated based on the system clock. One method cheaters use is to take a video clip of each spin to determine a time when a favorable seed appears. Players can also legitimately get a grasp of the timing by continuously playing a specific slot.

How to manipulate the RNG in video slot machines?

No one can influence the RNG or seed generation of nearly any physical or online slot games. PRNG algorithms of all slot games use a system clock or other factors that cannot be controlled by the players or even the casino itself.

Can you hack an online slot's RNG?

Incredibly difficult or next to impossible, but it is still possible to hack a slot RNG. Reputable software providers integrate high-grade security features onto their games, making their slots virtually impossible to hack. Dedicated or crafty criminals can still crack the security if they gain administration access for any slot games and find a way to manipulate its RNG.

Is a casino remotely controlling their random number generator?

Licensed casinos can get in trouble if they are found to have a hand on their slot's RNG. Fortunately, every certified slot games have unbreakable security on its software and algorithm, preventing anyone from taking advantage of a game's RNG.

Does slot random number generation use AI or ML?

Most slot games do not use AI to create random results. ML or machine learning is a tool that is mostly used to digest massive amounts of data and turn it into readable info. AI is better suited at using the overall data of a game such as average bet amount to help software providers and casino operators.

What algorithm do slot machines use?

Modern and online slot games use pseudo-random number generators (PRNG) to create random results. Using a random seed based on aspects of the computer system such as its time, PRNG generates a numbered sequence to determine which symbols appear on each pay line.

A slot RNG is designed to be unpredictable as a dice roll or coin flip in the natural world. By securing it from a casino's influence, you have a chance of hitting a high payout or even the jackpot of each slot.