A Guide to Random Number Generators in Online Casinos

Random number generators (RNGs) are crucial to the online gaming industry. In fact, RNGs are the heartbeat of the entire business and without them online casinos simply wouldn’t be fair, or fun places to play. At land-based venues, dealers randomise the cards by shuffling them. This can either be done using a single deck after every hand or, for games like blackjack, by loading a casino shoe with up to eight decks of pre-shuffled playing cards. At random number generator casinos, shuffling is replaced by a mathematical formula to ensure every card dealt, dice rolled, or wheel spun is completely random and therefore unpredictable.

Best RNG Casino 2019 The Fairest Slots & Table GamesAudited by eCOGRA

What Is an RNG and How Does It Work?

Traditionally, if you needed a random number you would use a method similar to what you see in a land-based casino; drawing cards, rolling dice, or even flipping coins. Lotteries and bingo games are essentially rustic RNGs too. As the need for larger quantities of random numbers became more urgent in statistics, computerised RNGs were developed. RNG casinos use what is known as a pseudorandom number generator (PRNG). The algorithm can create long strings of random numbers automatically, but the entire series is determined by a fixed number, called a seed. By manipulating this seed, developers can control the return to player rates of online casino games.

Infographic showing how a random number generator works

As you can see from the image above, this whole process of creating random numbers to generate fair outcomes is quite complex. Achieving ‘true’ randomness is very difficult, but with modern technology and computer systems, mathematicians and statisticians have gotten close enough for us to enjoy fair casino games without concern.

Why Is RNG Gaming Used at Online Casinos?

RNGs originally came into the casino business as a new way to run slot machines. In the past, slots used psychical reels to determine which symbols would land on (what was usually just a single) payline, to create winning combinations. Today, online slots are complicated and can be played over several paylines. Old-fashioned cogs and reels simply couldn’t handle this kind of complexity, and thus, without the birth of the RNG we would never have reached this point in online slots.

Aside from allowing developers to create more interesting, varied slot games, RNGs are essential for making games fair and honest. Imagine you are sitting in front of a slot game online. From the

minute the game loaded, it has been creating a string of random numbers behind the scenes. The sequence is constantly moving, and won’t stop until you hit the spin button. At this point, the sequence will be halted, and the random number is converted into a tangible outcome – reels coming to a stop, a card being dealt, the winning pocket on a roulette wheel etc. RNGs are tested by independent regulators, and casino sites will not be granted an operating licence if they fail these tests.

Can You Cheat an Online RNG?

The short answer is that, in theory at least, yes. RNGs are computerised algorithms, and therefore can theoretically be hacked. In practice, this is extremely difficult, bordering on impossible for 99% of online casino players. There was an incident in 2008 where a player named Ron Harris developed a program that could predict the result of an RNG, and he won a lot of money playing Keno as result, but he also ended up in prison for his efforts. Today, online casinos are tested regularly for fairness and the authenticity of their RNGs are thoroughly regulated. Unfair or hackable systems almost never slip through the net in the modern day online gambling industry. Let’s have a look at some of the UK’s testing agencies.

TST: Testing for iGaming and Beyond

TST is well-known in the iGaming industry for its technical audits of RNGs and other lottery and sportsbook operations. It also audits poker systems tests for vulnerability to hacking as well as full-scale security tests. The TST company has offices in Italy, London, Macau, Manila, The Netherlands and Vancouver, Canada.

eCOGRA – UK’s Trusted Auditor

As one of the biggest names in the business, it’s likely you have seen the eCOGRA logo peppered around the websites of your favourite online casinos. The London-based company is committed to fair gaming and responsible conduct by operators. Aside from looking into RNGs, its test measure casinos against its own generally accepted practice guidelines to make sure everything is in order before giving it the stamp of approval.

Verisign: A Forbes Favourite

Verisign is a global leader in technical audits for RNGs and the iGaming industry in general. The company, based in North America but with offices in India, China, Switzerland, Australia and the UK, offers a range of security services and is an expert in cyber-attacks. Any casino baring its seal can be assured its RNG is in safe hands.

Gaming Associates – Gaming Safety since 1990

Gaming Associates (GA) is a leading consultant to the iGaming industry on issues regarding regulations, security and fairness. Since the 1990s, when gambling regulations really ramped up, the need for expert advice on compliance has risen. GA works with operators to ensure they are legal, and to be legal, they need to have safe, fair RNGs.

Which Online Games Use RNGs?

All modern online casino games use RNGs to provide the luck element of their games. Since we moved into digitally rendered, software-based versions of slots, blackjack, roulette and everything else an RNG casino offers, the games have used numbers to determine their outcomes. The way this works is quite simple. The RNG works in in tandem with casino software to produce fair outcomes. If you are playing blackjack, the second you hit deal the RNG will feed the software a unique value. This value is essentially the result of the hand. In our example of blackjack, that means the order of all the cards dealt in that hand are pre-determined and random. In a game of roulette, the RNG value is converted into a winning number on the roulette wheel. And when it comes to slots, the RNG dictates the outcome of every single spin. Below are our favourite slot games where you can try this principle on your own.

After playing a few rounds for free, you’ll see that all games can be boiled down the RNG – and the rest is just decoration. The software creates the cards or paylines, provides us with gameplay actions and decision, and, of course, it’s the RNG that ultimately decides if we win or lose.

How About Live Casino Games?

Liver dealer games have risen in popularity over the last five years and are worth looking at as these games diverge significantly from the RNG gaming we have come so accustomed to. Live games use real human dealers and croupiers, real cards and real tables. Thus, it’s impossible for RNGs to be used to create fair outcomes. Instead,live games use the same techniques as land-based casinos to ensure the result or each round of play is random.

However, to prevent card counting and other exploitative strategies, live card games use a freshly shuffled deck of cards for each hand. The results of live games are still ‘random’, of course, but they are not quite as random as a true RNG. Still, for the average player, you won’t notice a difference. Some live providers, such as Evolution, reassure players of fairness by using multiple camera angles in the name of transparency. Live dealer games are also considered when an auditor assess the fairness and authenticity of an casino site, so anything with a valid licence and a legal audit certificate is safe and secure.

Should RNGs Change My Playing Strategy?

If you are using a card counting strategy, then you should definitely scrap it if you’re playing online casino games. Counting theories rely on a pre-shuffled deck being used to completion in order to be able to predict the ‘value’ of all of the remaining cards by keeping a mental record of everything that has previously been dealt and is therefore ‘known’. RNG games do not work in this way. Every single hand is completely randomised, making counting strategies redundant.

Betting pattern strategies for roulette, such as martingale, can still be used in an RNG casino online, as they do not rely on measuring how hot or cold a table is. Betting strategies instead rely on mathematical principle and therefore a truly random result generated by an RNG is actually beneficial to the system.

How Does the RNG Affect the RTP?

Here’s where the seed comes in. RNGs are programmed to pick certain combinations of numbers to achieve a consistent return to player (RTP) rate. As of September 2016, online casinos are required to monitor the actual RTP of its games to make sure the RNG is not faulty. This is done by dividing the total value of all payouts of a machine or game by the total turnover it has accrued. The result should be as close to the theoretical RTP as possible. If it isn’t, then the RNG is reviewed and tweaked.

As the machines are constantly creating numbers, the timing of pressing the spin button on a slot machine changes the outcome of that round. Of course, the outcome is still random, so there is no skill involved, but a split second could be the difference between a big win or a loss. Over time, these machines pay at certain rates due to the probability of certain numbers cropping up. This is why it’s called a ‘theoretical RTP’. True RTPs are also often published by operators. The best online casinos use RNGs where these two numbers are identical.

RNG Gaming – Conclusion

RNG technology has been not allowed online casino gaming to be realised, but it made casino gaming a fairer practice. Once the restrictions shuffling cards of moving-part machines are taken away, game-makers can truly get creative with designs, safe in the knowledge that RNGs mean that a random, unpredictable result can be applied to almost anything. Hit up our recommended random number generator casinos list to see for yourself!