Roulette Wheel: Layout and Structure of the Roulette Table

History of the Roulette Wheel

The origins of the roulette wheel date back as far as the 18th century. The mechanism of this attempt at a perpetual motion wheel came to light in the 1790s, when the game of roulette was derived as a fusion between several other wheel-based games, namely the Italian game of Biribi and the English game of Roly Poly. The earliest description of the game of roulette as we know it dates back to 1796, with roulette said to have been played at the Palais Royal in Paris.

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Roulette Wheel Inventor

The concept behind the roulette wheel was developed by a French physicist, mathematician and inventor, Blaise Pascal. In the mid-17th century, Pascal was attempting to devise the world’s first perpetual motion contraption – a machine that would not rely on external energy sources to operate indefinitely. Although his experiment failed, with many deeming perpetual motion to be impossible, the wheel Pascal invented was later used as a roulette wheel and adapted by Francois Blanc to incorporate a single zero, giving the casino a greater house edge – more on that shortly.

Understanding the Roulette table

First and foremost, it’s important to explain the difference between the roulette wheel and the roulette table. The former is the wheel that spins around with 37-38 different numbered pockets for the ball to land in. The roulette table is your interface for betting on the outcome of the next spin of the wheel. Each number is displayed in the roulette table layout, along with the other fields for all potential call bets.

You can cover as many numbers as you like for an upcoming spin. You can straight bet on a single number up to a maximum of 18 numbers, each of which is odd or even, or red or black. There are also several other types of wagers. 

Roulette Wheel Layout and Design

Roulette wheel numbers and sequence

Numbers on a roulette wheel go from 1 to 36. Depending on the type of roulette wheel you choose to play, you will also find a 0 or even a double 00 too.

The sequence of numbers on a roulette wheel is not related to their mathematic value whatsoever. The sequence of odd and even, as well as red and black numbers is evenly distributed around the wheel in a bid to ensure a fairer, more balanced game.

Roulette Wheel Colours

You’ll find that the pockets of a roulette wheel will have one of three different colours. First and foremost, 1 to 36 will be displayed in alternate red and black colours. Secondly, the zero (like, for example, in European Roulette, or the creative Age of the Gods™ Roulette) – and double zero (in American Roulette), if present – will be displayed in a prominent green. With only a few colours to keep an eye on as the wheel spins, it’s easy to see why beginners find roulette easy to pick up.

Ball Track

The ball track of a roulette wheel is the "run" for the roulette ball to move around as the wheel spins. Eventually, as the ball slows down and the centrifugal force is no longer sufficient enough to sustain it on the track, the ball drops into one of the pockets built into the roulette wheel – hopefully, a winning pocket for you!


The only instance where there is another pocket on the roulette wheel is when you play Diamond Bet Roulette™. The diamond is an additional pocket to the numbers that's assigned a random win multiplier by online casino software when you bet on the diamond.

Roulette pockets

You may have already heard us talk about pockets on a roulette wheel, but let’s go into a little more detail. Most roulette wheels have frets of the same height at both ends of each pocket. Meanwhile, some other wheels have pocket frets that diminish towards the centre of the wheel, which can sometimes make it seem harder to estimate where the roulette ball will land.

Roulette rotor

In terms of the inner workings of a roulette wheel, its rotor is arguably the most important mechanism to keep your gameplay moving. It ensures the wheel and its pockets spin at a consistent speed, helping to reduce – eradicate, when you're playing at a reputable casino – the possibility of wheel bias during any roulette game.

Roulette base

The base of a roulette wheel is its outer shell. In most high-end land-based casinos, these will be wooden, complete with a metallic interior to help shield and protect the roulette rotor and the other inner mechanics of the roulette machine. The slightest imperfection to a roulette base can also affect the performance of a wheel’s ball track.

Find out more about roulette odds and betting systems in Paddy Power’s guide.

Differences Between the Roulette Variations

European vs American vs French Roulette

It’s very easy to distinguish between European and American roulette wheels. Just take a look at them! American roulette wheels have two zeroes – a single zero and a double zero. European roulette wheels have only a single zero, thereby reducing the house edge of European roulette games to 2.7%, compared with 5.3% with American roulette.

The main difference between American and French Roulette is the way outside bets (odd, even, red, black, high, low) are treated when the ball lands on a zero. In the American and European versions, all outside bets are lost. However, in the French version, the roulette strategy can be different, since you can choose to keep (or "jail") your outside bet on the same number(s) for the next spin. Some other French tables will adopt the "La Partage" rule, where only half your stake on outside bets is refunded to you. These French roulette rules are unique to this variant but we should also point out that French roulette only has one zero, like European roulette.

European Roulette layout asymmetries

There is one fascinating quirk with the layout of European roulette wheels. If you halve the circumference of the roulette wheel from the zero, the left-hand side will display all the black low numbers and all the high-value reds. On the opposite side, you’ll see the low-value reds and the higher-value blacks, in rather asymmetrical fashion.

Brick-and-mortar roulette vs online roulette

If you enjoy the gameplay of roulette more than the pomp and ceremony of dressing up to go to a land-based casino, you’ll probably prefer playing online roulette. The action unfolds much faster, given that all players are paid automatically by the game’s software, saving you plenty of time in between spins. There’s no denying that being able to play online roulette from the comfort of your own home is also a major benefit over brick-and-mortar roulette. Finally, bearing in mind that independent third parties always vet the systems used by reputable online casinos, it's much easier to know that the online roulette wheel is reliable and unbiased. 

Another benefit of playing roulette online is that you can have a richer experience by trying out the jackpot roulette games.

Online roulette vs live roulette

If you truly want a land-based roulette experience but you can’t be bothered to go to your nearest casino, live dealer roulette was practically made for you. Streamed in real time to your device, these games are managed by human croupiers, giving you an immersive bricks-and-mortar style gameplay and interaction without you having to leave your armchair. You can even play on your phone or tablet.

The Advantages of Playing Online Roulette

No manufacturing defects

If you want genuine peace of mind when playing roulette, online versions offer total transparency. As they make use of RNGs, which are regularly audited and verified by independent third parties, there is no threat of manufacturing defects that could create a bias on the roulette machine as it happens in real-life settings. In short, online roulette is demonstrably fair. 

What is the deceleration rate and how does it impact the roulette game outcome?

Over time, land-based casino roulette wheels can deteriorate, leading to the deceleration of roulette balls and subsequent bias. To put it simply, these wheels are no longer fair. Although significant progress has been made by physical roulette wheel manufacturers to combat this issue, online roulette players don’t have to worry about deceleration rates, as the outcome of each spin is randomly determined in line with the wheel’s RNG.

No errors made by croupiers

As we’ve already touched upon, when you get a winning number playing online roulette, you don’t have to hang around waiting for your croupier to calculate your payout. The software does it all for you and is supremely accurate, with no threat of human error slowing down your gameplay.

You can sit at several tables at the same time

Do you like the idea of being able to dabble with playing multiple roulette variants at the same time? With online roulette, that’s entirely possible, with the option of playing multiple screens on your device at once. On the flip side, it would defy the laws of physics for you to be able to play at two or more roulette tables at once in a land-based casino!

Roulette manufacturers

When you play online roulette at sites like Paddy Power Games, you don’t have to worry about whether the roulette wheel manufacturer is credible and genuine. Our state-of-the-art online and live roulette games are developed and provided by award-winning software studios so that you can focus on enjoying the action on this classic casino spinning wheel.

We hope the above breakdown has answered all your questions about both offline and online roulette tables. Ready to get stuck into the action? Head to our roulette lobby to discover a wide range of fascinating roulette table variants! 



Random number generators (RNGs) are computer algorithms that produce random outcomes for each and every spin of a virtual roulette wheel. RNGs are not applicable to physical roulette machine tables of the sort you'd find in a land-based casino. However, online casino roulette wheels depend on RNGs to ensure the fairest, most transparent action for casino fans. At reliable, regulated casino providers like Paddy Power, all casino games along with their RNGs have been vetted by third parties, which means that the gameplay has been checked by independent agencies to make sure it is completely fair for all.


A house edge for a roulette wheel is determined by calculating the odds against a winning bet, minus the house odds, multiplied by the probability of winning a bet.

For example, let's say that you've placed a straight bet on a single number, with the odds against you winning at 36/1. The house odds are 35/1 and the probability of success is 1/37:

The house edge equals: (36/1 – 35/1) x 1/37 = 0.0270270

Multiply that by 100 to get the house edge percentage of 2.70%. This means that for every £100 that the totality of players spend on the roulette wheel spinner, players would statistically lose £2.70 on average to the casino. From that, it follows that for every £100 all players spend on the game, players win back £97.3 in total, on average.