There are 2 main ways of playing online roulette. The first is live dealer roulette, where you play on a physical wheel that normally sits in a studio, but can also sit in a land-based casino somewhere (this is getting more popular- a system in which online players play "alongside" players who are physically at the casino). In both cases, the action is beamed to you over a webcam, or a series of webcams and you place your bets on a virtual table online.
The second way of playing online roulette, is on a virtual game which is powered by a RNG or Random Number Generator. If you have ever been to a casino like the Hippodrome in the West End, you'll have noticed that the main floor is usually filled with blackjack, roulette and baccarat tables. And around the sides, you'll generally find the slot machines and the video roulette machines.
Playing virtual roulette online is close to playing one of those machines. They are essentially video games that have been programmed to match the behaviour of a real roulette wheel.
How Random is an RNG?
But just how random is online roulette? Someone must have programmed it right? Are online roulette games rigged?
Theoretically, online roulette is easy to rig. It's just a program, and you can edit the code of a program easily, can't you?
Well, thankfully, there are quite a few safeguards in place to protect players in this area. Casinos that resort to these kinds of nefarious business practices risk losing their gambling licences and their whole reputation which, once lost, or hard to get back. All the casinos we feature on this site are licensed by the UK Government or by the Government of Malta. These licensing jurisdictions have been set up to protect players and to ensure that the games are fair and pay winnings out at an agreed pay-out percentage.
Most online casinos licence their games from casino games developers such as Microgaming, Playtech and NetEnt. These company's games are closely audited to ensure that they play by the rules and their operations are run ethically. Tampering with the code would be very hard to hide and would be a huge risk to their shareholders and stakeholders.
So, if you play at a reputable online casino that has a licence from a decent jurisdiction, you can be sure that the RNG is fair and accurately mimics a real roulette wheel. Frankly speaking, casinos already have an edge against players- this is how they run their businesses and make a profit. They don't NEED to rig the system! Some player win, some players lose in any given day, but over the long term, the house should always be able to make a profit. That's not to say that they don't have bad days, weeks, or even months even. There are plenty of examples of casinos having to issue profit warnings following a winning spree from some particularly lucky customers. But in the LONG TERM, they hold the advantage.
When playing European roulette the house edge is about 2.7% and for American roulette, it's around 5.3%.
In order to generate random results, the RNGs in online roulette games are programmed with advanced formulae. There are two different principles used to achieve this. Algorithms are used to generate long sequences of random outcomes.
The numbers you'll see in online roulette are pseudorandom numbers or computer-generated random numbers. We use pseudo to distinguish these types of number from "pure" random number generated by physical processes such as radioactive decay.
Some casinos use physical processes to generate their numbers (or so they say). Two examples are using white noise from two independent Zener diodes and a radioactive decay measurement.
How Does an RNG work in an Online Roulette Game?
This is not an easy one to answer, of course, as roulette game manufacturers hardly make this kind of information public for fear of people cracking the code and devising some way of predicting the results on a machine.
An RNG is a computer program or algorithm that generates results at random.
Pseudo Random Number Generators just need an algorithm and a seed number.
New seed numbers are generated every millisecond by taking the last number or two or three (and so on) produced, and then using a formula to create a new ‘random’ outcome. Then you repeat and repeat again.
These are why these programs are such closely guarded secrets- no one person is likely to know the whole code. If someone knew what algorithm and seed numbers were used, they could use that information to cheat the casinos out of a lot of money