How Are Random Number Generators Used In Casino & Slot Games

random generatorIt would be surprising if even the most analytically minded gambler didn’t at one point or another consider that their luck was in. It’s a natural feeling to wonder if the fates are with when you’re having a flutter, especially when playing casino games. It’s easy to see how the stars might align in terms of playing card games such as baccarat or blackjack, given that shuffles will always have a touch of human frailty to them. Likewise it’s easy to imagine the invisible hand of fortune reaching down and helping the ball slip into a winning slot on the roulette ball, if you’re naturally inclined to believe in such things. Ultimately the game of roulette when controlled by a human dealer requires them to select where to spin the ball from and how much power to give the push of the ball, meaning that one slight change from spin to spin could result in you winning big.

When it comes to casino gaming cabinets and online games (other than live casino), however, things aren’t quite so simple. There is no human element to proceedings, with even the most popular of slot machine games requiring the influence of a sophisticated algorithm in order to ensure that results are as random as possible. Yet can anything ever be truly random?

Can even a computer come up with a numerical system that has no pattern? How does this apply to Random Number Generators and, perhaps more importantly, how does that apply to casinos? On this page we’ll look to answer all of those questions, giving you a real sense of just how ‘random’ those slot machines and other computer-controlled games actually are.

What Are Random Number Generators

randomnessSimply put, ‘Random Number Generator’, or RNG's as they are often referred to, is a term used to describe a method coming up with a sequence of symbols or numbers that is hard to predict, making it as close to actual ‘randomness’ as it’s possible to get.

Examples of somewhat simplistic randomisers include the flipping of a coin or the rolling of a dice. The selection of a card from a shuffled deck is another example, though it’s difficult to truly shuffle a deck of cards enough to make this entirely random all of the time. They are what you might refer to as ‘old school’ Random Number Generators, whereas the things that we’re more used to encounter nowadays are powered by computers.

Once you start to dig a little deeper about RNGs you soon discover that you’re entering something of a rabbit hole. The key phrase to the whole thing is ‘deterministic computation’, given that’s what’s involved in computers coming up with random numbers. As we’ll explore shortly, however, it’s difficult for them to ever be truly random. As a result, these sort of RNGs are known as pseudorandom number generation devices.

In point of fact, it’s not as important for all things in normal life to be as ‘random’ as you might imagine. The thing to think about with this is your music device and the ability to put on shuffle. If it was truly random then the same song could play several times in a row, but it doesn’t because algorithms are put in place to stop that from happening.

Can RNG's Truly Be Random?

roulette wheelWith that in mind, then, can these processes ever be truly random? That’s a question that’s incredibly difficult to answer. The majority of Software based RNGs depend on mathematical algorithms in order to create their ‘random’ outcomes. They all use an initial ‘seed’ to get the process of randomisation underway, which can be anything from the time on a clock through to the number of keystrokes needed to type a sentence.

The issue is that the outcome of the randomisation can be discovered if users are able to find out the full seed values. In reality, of course, this would be virtually impossible to do. Yet the fact that it can be done, combined with the fact that an initial seed value is needed in the first place, means that the results are not truly random.

The way around this is to avoid using a seed value at all, if possible. This can be done using what are known as Truly Random Number Generators, or Hardware based RNGs. The random numbers aren’t created by computers, rather they are the result of a digital snapshot of noises that occur naturally in life. 

That can be the likes of waves crashing on a beach, bird song or white noise. There’s then no repeating of values, meaning that anyone who was able to identify one of the numbers involved wouldn’t be able to use that to predict the numbers that would come next. It’s the purest form of Random Number Generator, which is why it gets the word ‘truly’ put in front of it.

The Different Types Of RNGs

RNG TypeHow It WorksTruly Random?
Old School Rolling of die, selection of a card, drawing of straws Yes, but limited application owing to few possible outcomes
Software RNGs Uses mathematical algorithms and a ‘seed’ to begin the randomisation No. The initial seed number means that it can theoretically be predicted
Hardware RNGs Uses naturally occurring events such as noise or pollution count to begin randomisation As close as it’s possible to get at the time of writing.

Having Looked at the three different types in detail, above is a quick table to help you understand them more simply.

What RNGs Can Be Used For

casino gamesNow that we’ve got a slightly greater understanding of the different types of Random Number Generators and the ways in which they work, it’s worth considering what, exactly, they can be used for. We’ve already made mention of the shuffle function on a music player, as an example, but that’s not all that useful for casinos. Perhaps physical casinos can use it to change music they might play over their public address system, but you take the point.

As we’ve already established, RNGs can give out numbers at random. The most obvious use for them comes with the likes of a lottery, which requires numbers to be sent through at random out of a select amount of possible options. They can be adapted to be used in countless other games, however, especially when you’re looking at online casinos. Essentially, the outcome of any ‘virtual’ game can be decided by using a Random Number Generator. Here’s a list of the sorts of games that you’ll almost certainly find RNGs being used for:

How The RNGs Decide The Outcome Of Games

number crunchingIn order to explain how they come into use more succinctly, let’s have a look at the world of slot machines. Whether you’re playing one online or using a computerised version in a physical casino, slot machines tend to have a set number of reels and a given number of lines on which you can win money if symbols line up correctly. For arguments sake, let’s assume that we’re looking at a three-reel slot machine with twenty symbols per reel. The lines that you’ve selected to play won’t be influenced by the RNG, so we can forget about them.

The Random Number Generator will be used to assign each of the twenty possible symbols with a value, ranging from one to twenty. They will do this for each of the different reels, meaning that there can be a huge number of possible outcomes. When you press spin, the RNG will randomly decide which number will come up on each reel, though that number will be displayed to you as a symbol. Here’s what it could look like, simplistically speaking:

  • Reel One: 7
  • Reel Two: 19
  • Reel Three: 1

If the rules of the game declare that the symbols represented by 7, 19 and 1 make a winning combination then you will be paid out accordingly. If they don’t then you won’t be. From a front-end point of view it really is that simple, though the work going on behind the scenes is obviously incredibly complex.

You can extrapolate those workings out across the numerous games that have been listed above. In electronic roulette, say, the RNG will generate a number between zero and thirty-six if you’re playing the European variation, or adding in a double-zero if you’re on the American version of the game. Whichever number the Random Number Generator spits out is where the ball will land. The rest of the complexity when it comes to roulette is all about the betting, but that doesn’t influence the RNG. The algorithm has no need to decide upon whether it’s an Odd or Even, or whether the ball is in the 1st, 2nd or 3rd section.

chances of winning

The complexity of the inner workings of a Random Number Generator is best explained using the likes of blackjack. Once again, the algorithm will assign each playing card in the deck a value between one and fifty-two, presuming that it’s a one-deck game. Let’s say that there are five players and the dealer. The RNG will then assign each player with a number that represents a card, one at a time, then again a second time around. If a player wants to take a hit, split or some other action allowed in the rules of the game, the RNG will come up with a random number accordingly. Here’s how it might look:

First Card:

  • Player One: 51
  • Player Two: 34
  • Player Three: 2
  • Player Four: 20
  • Player Five: 49
  • Dealer: 7

Second Card:

This time the RNG will know that it cannot give out any of the numbers that it’s already used, so it will select from the remaining forty-six cards - just as a real life dealer would with a true pack of card.

  • Player One: 19
  • Player Two: 47
  • Player Three: 5
  • Player Four: 28
  • Player Five: 1
  • Dealer: 33

The RNG needs to take into account both the number of players and the cards that have already been dealt, which becomes more complex if you start playing with multiple decks and so on.

If one to thirteen were the Spades, fourteen to twenty-six the Hearts, twenty-seven to thirty-nine the Clubs and forty to fifty-two the Diamonds, with Ace being one, then numbers moving up accordingly and Jack being 11, Queen being 12 and King being 13, the hands would look like this:

  • Player One: Queen of Diamonds - six of Hearts
  • Player Two: eight of Clubs - eight of Diamonds
  • Player Three: two of Spades - five of Spades
  • Player Four: seven of Hearts - two of Clubs
  • Player Five: ten of Diamonds - Ace of Spades
  • Dealer: seven of Spades - seven of Clubs

You can see that in that example Player One would have sixteen and probably stick, Player Two would have sixteen and also hit, Player Three would have seven and definitely hit, Player Four would have nine and also hit, Player Five would have twenty-one and automatically paid out (unless the casino’s rules only did that for face cards and aces), and the Dealer would have fourteen and be forced to hit. The RNG would then pick random cards according to their associated numbers in order to fulfil the ‘hit’ desires of those players wanting to take them.

Obviously this is a simplistic example, but it gives you a sense of how an RNG would work in terms of associating cards with numbers and then assigning a number to each player in order to form a hand in blackjack.

Why Games Need To Be Random

fixed odds betting terminal being played in a betting shopGiven all of this talk about the randomness of the different games, it’s naturally to wonder why randomness matters. The answer comes in the casino’s unwillingness to lose money and the ability of players to predict what will happen next if things aren’t random.

Let’s look at the above examples to see what we’re talking about more clearly. If you were able to sit and play the roulette for an hour and figure out that the number shifted by thirty-seven every fourth time the ball landed, you’d be able to extrapolate from that to get to the point of figuring out what number it will land on next time.

Likewise, in the blackjack game, if you’d been able to identify that the card number increased by seventeen every six times a card was revealed, you’d be able to work out what card you’d get if you took a hit. From there you’d know whether to do it and the likelihood of the dealer going bust. There have been card counters over the years who have used exactly that method, winning a huge amount of money at the expense of casinos. The powers that be obviously want to keep hold of their money and only lose it when it’s fair.

Speaking of fair, that’s something else that everyone needs to remember. Both the casinos themselves and the players that use them accept that the House has an edge. We’re all willing to go along with that because we believe we’ll be able to win some money for ourselves, however naive that belief might be. If you remove that fairness and fix things so that players only win every fifteen hands, or that the roulette ball lands on zero more often than it statistically should, people will lose their faith in the casino and simply stop attending it or logging on to use its services.

That’s why Random Number Generators are such an important part of slot machines. When you start playing one you’re informed about the Return To Player average, known as the RTP for simplicity. Again, you accept that the casino gets an edge on the games, but you need to know that you’ll get some money back and if things weren’t random you might feel like that wouldn’t happen.

Random Patterns

random patternWhen it comes to Random Number Generators, one of the things that we need to think about is whether or not even randomised sequences can feature patterns. The reality is that for something to be truly random it shouldn’t feature any identifiable patterns, yet even something genuinely and naturally random can still seem to feature patterns if you look closely enough.

Rainfall or snowflakes will be random in their dispersion, and yet the manner in which they fall can be predicted by those that watch. So if something is going to be artificially created in order to be random and feature no patterns, that means it will go against the natural way of things. Sound complicated?

If a Random Number Generator is launched from a seed and not linked to an external source to create said seed, the initial number will be psuedo-random. That does not automatically mean that it wouldn’t then be useable by a casino, however. Even a psuedo-random sequence should be almost impossible for anyone to predict the pattern of. The problem is, of course, mathematics is certain. One plus one will always equal two, meaning that if there’s an mathematical equation involved in starting off a random generator then it will be definition be possible to work out what will happen next. The fortunate thing is that these equations are so complex and so multifaceted that that can practically never happen.

The Real World Versus Online

casino player cheating

Yes, this might be a conversation topic that you need to have with a teenage boy at some point in the future. For now, though, we’re talking about the difference between online games and real life casino gaming.

The laws of motion will dictate where the dice will land if you step up and play a game of Craps. Three-Card Poker will be made random by the shuffling of the deck by the dealer and the cutting chosen by one of the players. Where the ball will land on a roulette wheel can be altered by something as simple as the strength with which the dealer decides to push it before they choose to send it on its spin. All of the game played in a casino that involve physical actions done by real people are likely to be naturally random in a fair game.

It’s in the move to online gaming that we suddenly require the Random Number Generators. As mentioned before, if some had the initial seed number then it would be theoretical to figure out the pattern and make successful predictions of where things are going next. Yet the reality is that most online casinos pick a seed number that contains well over 200,000 digits, before we even get into how the seed number is picked in the first place.

When it comes to the likes of slot machines that you can play in a casino, video poker or the computerised roulette wheels that many have around today, they use the same sort of RNGs that online sites use and are therefore just as secure and safe to play.

Ensuring Fair Play And Safety

casino scam

It’s an obvious thing to mention, but it is the responsibility of the Gambling Commission to ensure that the Random Number Generators used by casinos that they issue a Gambling Licence to is fair and proper.

The companies that create RNGs, as well as the online casinos that use them and the gamers that they feature in are all tested on a regular basis with the specific aim of ensure that they meet rigorous standards.

It’s also worth noting that it’s not just one or two companies that do this, which could lead to corruption or outside influence causing a lack of fairness and transparency for consumers. Instead there are a whole host of third-parties that are responsible for checking RNGs and have the backing of the Gambling Commission. Here’s a list of some of them:

  • eCOGRA
  • iTech Labs
  • Gaming Associates
  • GLI Test Labs Canada ULC
  • GLI Europe BV
  • NMI Metrology & Gaming Ltd
  • BMM Compliance
  • SQS India Info systems PVT Ltd

That list is far from exhaustive, but it does give you an idea of the number of companies out there that are responsible for ensuring your safety online. If you’re interested to know which one of the myriad of available companies that the casino you bet with uses to check up on their RNGs, make sure to look out for the symbol or icon that will be featured somewhere on your casino's website.

In order to pass muster, the game must make it through numerous statistical tests that are designed to see whether or not there is an bias involved, as well as be found to show no operational flaws that could allow the casino operator to move the house edge.

Can RNGs Be Rigged?

against all oddsAll of that is not to say that Random Number Generators are in no way unimpeachable. There was a famous example in America of a man named Eddie Tipton, who helped to rig lottery computers when he worked for the Multi-State Lottery Association as its security director. He arranged it so that certain numbers would be chosen by certain machines on certain days, thereby removing the randomness of the lottery in those places entirely.

That obviously required a backdoor to be placed into the lottery machines at the highest level, meaning that you’d need to be ‘in on it’ to take advantage. If you wanted to ‘hack’ an RNG then it would theoretically be possible, but the amount of research that you’d need to do and the amount of time it would take would make it virtually pointless.

What’s interesting is that that might change as computers become more and more powerful. They’ll soon be able to work at hacking the RNGs on a consistent basis. In a massive contradiction to that, however, the more powerful computers become the more likely it will be that they’ll be able to develop even more convoluted Random Number Generators and the seeds required to operate them.

This means that it is highly unlikely that RNGs will ever be rigged or hacked. You can read more about rigging in general here.

Avoiding Pitfalls By Understanding How RNGs Work

The PitfallThe Truth
Thinking You’re On A Hot Streak Every single time an RNG is required to come up with a number, it does so with no prior knowledge of what’s happened before. The fact you’ve ‘won’ three hands in a row before makes no difference to what will happen next.
Belief You’ll Win More Often If You Bet More Some progressive slot machines allow players placing higher stakes to win more often by ‘unlocking’ different jackpot amounts, but for standard games you’ll win the same amount of times regardless of how much money you’re betting with.
You’ve Won Big, You Won’t Win Again Refer back to the hot streak segment. The fact that you’ve won big doesn’t mean it’s time to walk away from a machine. The randomisation of a Random Number Generator means that the previous outcome has no bearing on what the next outcome will be.
RNGs Allow Casinos To Cheat This can probably be filed under ‘paranoia’, given that casinos that have UK Gambling Commission licences have to be tested on a regular basis. It might feel like you’re never winning, but the reality is that that’s because the House has an edge and not that you’re being cheated.

There are numerous pitfalls that casino players fall into. Whether it’s believing that blowing on the dice is making a difference when you’re playing Craps or feeling that you have a ‘lucky chair’ at the poker table, some people love to get caught up in the world of superstitions.

Now that you have a clearer idea of how Random Number Generators work, you can work hard to avoid falling into some of those pitfalls. Above we a look at the main ones.