How Does Roulette Work? The Wheel, the Table and the Mechanics Explained

Ever thought about how does roulette work in terms of all the mechanics involved? We’ve put together this guide to take a look at the engineering and procedure behind the game, so expect to learn about the following:

The wheel
The table
The croupier
The sequence that turns a spinning ball into a settled result
The full mechanics of roulette, from the physics of the wheel to the seven steps a croupier follows on every round
The history behind the modern wheel
How the wheel and table are built
What a croupier does from betting open to settlement
How the variants compare
How online and live dealer versions reproduce the same mechanics through software and video

Got something in mind that we’ve not covered throughout? You’ll probably find it in our FAQ section at the end - let’s get started!

How Does the Game of Roulette Work? A Brief History of Roulette

The roulette wheel's origins trace back further than the casino floor. You’ve got to go back to 1655 where there was a mathematician, Blaise Pascal, trying to build a perpetual motion machine that would spin indefinitely without any outside force.

He never did that, of course, but what he did come up with was this near-frictionless mechanism that’s largely looked at as the earliest form of the roulette wheel.

The game itself took shape in France during the early eighteenth century, developing out of older games called hoca and portique. A precise 1716 reference from Bordeaux is often repeated online but hard to verify; the earliest reliably documented mention dates to 1758, when regulations in the French colony of New France banned hoca, faro and roulette by name.

By around 1790, the wheel's design had become largely standardised across European casinos. The most significant technical change came in 1843, when François and Louis Blanc introduced a single-zero wheel at a spa casino in Bad Homburg, Germany, cutting the house edge roughly in half.

That single-zero wheel became the template for European Roulette, and the format later spread to Monaco's Monte Carlo casino once François Blanc established operations there two decades afterward.

Roulette's path in America went differently. During the 1800s, operators added a second zero pocket, the "00", increasing the house edge and creating the lasting split between the European and American formats still seen today.

France banned gambling entirely between 1836 and 1933, pushing the game's cultural centre toward Monte Carlo and helping cement procedural traditions, including the croupier's methodical style, that carried through into the modern game.

The wheel, the table layout and the number arrangement in use today are the product of more than two centuries of engineering and regulation, refined into the fixed format used at every licensed casino now, which is how does roulette work as a modern game.

How Does a Roulette Wheel Work? Engineering, Balance and Design

So, the main thing to have in mind is this solid wooden disc. It’s a bit convex in terms of shape, and it’s stuck on this spindle so it’s rotating without much friction at all. Then there are these metal partitions called separators, or "frets", around its outer edge - those are what divide the disc into individual compartments. You sometimes hear croupiers call them "canoes" since they’re curved like a canoe.

Now, your standard European wheel has 37 of these pockets, numbered 0 through 36. The American wheel, however, has 38, since they’ve added a second "00" pocket next to the single zero. But on both versions of the game, you can expect the pockets to alternate between red and black. Except the zero or zeros. Those are always green.

Obviously, any wheel that is even slightly out of balance can develop a bit of bias toward certain numbers over time, so you’ll be glad to know that casino wheels are made to be precise and are checked regularly. What we’re left with is a spin that’s, as close as manufacturing allows, random.

So, what does the rest of the arrangement of numbers around the wheel look like?

We’ve got four main design principles here:

Colours alternate, so no two adjacent pockets share the same colour
High and low numbers, 1 to 18 and 19 to 36 are distributed evenly around the wheel
Odd and even numbers are arranged so no more than two consecutive pockets share the same parity
The overall sequence prevents any sort of visual pattern a player could use to anticipate where the ball might land.

European sequence	American sequence
0, 32, 15, 19, 4, 21, 2, 25, 17, 34, 6, 27, 13, 36, 11, 30, 8, 23, 10, 5, 24, 16, 33, 1, 20, 14, 31, 9, 22, 18, 29, 7, 28, 12, 35, 3, 26.	0, 28, 9, 26, 30, 11, 7, 20, 32, 17, 5, 22, 34, 15, 3, 24, 36, 13, 1, 00, 27, 10, 25, 29, 12, 8, 19, 31, 18, 6, 21, 33, 16, 4, 23, 35, 14, 2.

So, that’s how does roulette work before the ball is ever released.

The Roulette Table: Layout, Zones and Chip Conventions

A roulette table is really two connected systems working together: the wheel, and the betting layout printed on the green baize beside it, which mirrors the wheel's structure in a flat, accessible format.

Some tables place the wheel at one end with a single layout extending outward; others position the wheel centrally, with a layout on either side so two groups of players can bet on the same spin at once.

The layout itself opens with the zero (and, on an American table, the double zero), followed by 36 numbered spaces arranged in three columns of twelve, alternating red and black, running from 1 at the top to 36 at the bottom.

Around this central grid sit the outside betting zones: sections marked "1st 12", "2nd 12" and "3rd 12" for the three dozens, column markers at the foot of each column, and the even-money zones for Red/Black, Odd/Even and Low/High.

European and French tables often add an oval "racetrack" layout alongside the main grid, used for call bets that group numbers by their position on the wheel.

Chip conventions add another layer to how does roulette work at the table. Casinos typically supply up to ten sets of colour-differentiated chips, known as wheel checks, so several players can bet at the same table without confusion, with a traditional set containing around 300 chips.

The colour identifies which player owns which stack; it carries no fixed value of its own, which prevents disputes over whose bet is whose. When a player wants to bet at a higher denomination, the croupier places a marker, known as a "dolly", on top of the relevant stack to note its assigned value for that round.

Higher-value chips, printed with their denomination, can be used at any table in the casino, unlike wheel checks, which are only valid where they were purchased.

The Croupier: Role, Technique and Procedure

Every round of roulette follows the same controlled, seven-step sequence, carried out by the croupier with the same precision each time it happens.

First, the round opens. The croupier announces that betting is open, and players place their chips on the sections of the layout they want to back, whether single numbers, groups of numbers, or one of the outside zones.

Second, the wheel is set in motion. The croupier spins it counterclockwise with a practised motion, and it must be turning smoothly before the ball is introduced.

Third, the ball is released. Using an ivory or plastic ball, the croupier sends it around the back track of the wheel's bowl in the opposite direction to the wheel's rotation. It is this opposing motion, and the eventual collision between ball and wheel, that produces the unpredictable deflection pattern behind every result.

Fourth, betting closes. As the ball loses momentum and begins to drop from the back track toward the wheel, the croupier calls "no more bets", in French casinos still often heard as "rien ne va plus". From this point, no further chips may be placed, moved or removed.

Fifth, the outcome is decided. The ball continues to lose energy, deflects off the metal frets between pockets, and eventually settles into one of the numbered compartments. That pocket determines the winning number, its colour, and every bet type connected to it.

Sixth, the result is marked. The croupier announces the winning number and colour aloud and places the dolly on that number. While the dolly remains in place, no chips on the table may be touched by anyone until settlement is complete.

Seventh, bets are settled. Losing bets are swept away using a rake, while winning stacks are left untouched and then paid according to the game's fixed odds. Once payment is complete, the dolly is removed and the next round begins.

This sequence exists for a reason beyond tradition. Each step is a checkpoint that prevents disputes, keeps the game auditable, and protects the integrity of the result, which is precisely how does roulette work as a controlled banking game with a fixed, repeatable procedure.

How Does the Game of Roulette Work? Bet Types and Mechanics

Understanding each bet type also means understanding how does roulette work at the level of chip placement: every bet corresponds to a specific chip placement, and every placement carries a fixed payout set by how many numbers it covers.

Inside bets are placed within the numbered grid itself. A Straight, or "en plein", is a single chip on one number, paying 35 to 1. A Split, "à cheval", sits on the line between two adjacent numbers, paying 17 to 1. A Street, "transversale pleine", covers three numbers in a row and pays 11 to 1.

A Corner, "en carré", sits at the intersection of four numbers and pays 8 to 1. A Line, "sixaine", covers six numbers across two adjoining streets and pays 5 to 1.

Outside bets sit in the zones surrounding the main grid. A Column bet covers 12 numbers and pays 2 to 1, as does a Dozen bet. Low and High bets, "manque" and "passe", cover 1 to 18 or 19 to 36 and pay even money, as do Red/Black and Odd/Even.

The mechanical reason the house holds an edge on every one of these bets comes down to the zero. None of the outside, even-money bets cover the zero pocket, so when the ball lands there, all of those bets lose. That single design choice is the structural source of the casino's edge on every spin.

Betting systems such as Martingale are sometimes discussed in relation to roulette, and it is worth being clear here: mathematically, no betting system changes the underlying odds or overcomes the house edge over time.

European vs American vs French Roulette: How the Mechanics Differ

The three main variants show how does roulette work differently across regions: the wheel, the ball and the croupier's procedure stay the same, but the number of pockets and a handful of specific rules create real differences in house edge worth comparing side by side.

Variant	Pockets	Zero(s)	House Edge	Special Rule
European	37	0	2.7%	None (En Prison optional)
French	37	0	1.35% on even-money bets	La Partage
American	38	0 and 00	5.26%	Five-number line bet (~7.89% edge)

European Roulette uses the standard 37-pocket single-zero wheel described earlier, with a house edge of 2.7% across all bets. French Roulette uses an identical wheel but adds the La Partage rule, returning half of any even-money stake to the player if the ball lands on zero, which halves the house edge on those bets to around 1.35%.

Some European tables offer En Prison instead, where an even-money bet that loses to zero is "imprisoned" for one more spin rather than lost outright.

American Roulette adds the second "00" pocket, taking the wheel to 38 numbers and raising the house edge to 5.26% across the board. It also introduces a five-number line bet covering 0, 00, 1, 2 and 3, carrying a steeper house edge of roughly 7.89%.

These differences come directly from how many pockets the ball can fall into and which rules, if any, soften the impact of the zero on outside bets.

How Does Online Roulette Work?

The mechanics described so far apply just as much online, though the details depend on which of two formats you are playing.
RNG roulette, short for random number generator roulette, replaces the physical wheel with certified software that generates each spin's result electronically. Every spin is statistically independent of the one before it, and UK Gambling Commission licensing requires that software be tested and audited by an independent laboratory to confirm fairness and the stated house edge.

An online roulette game played this way uses the same wheel layout, number sequence and house edge as its physical counterpart, whether you are visiting the casino lobby or a dedicated table.

Live dealer roulette works differently. A real wheel is spun by a real croupier inside a purpose-built studio, with the action streamed to your device in real time. The croupier follows the same seven-step procedure described earlier, and you place bets through a digital interface before the croupier calls "no more bets".

Because a physical wheel determines the outcome, the result comes from the same mechanical process as an in-person table, just relayed by video, and licensing conditions from the UK Gambling Commission still apply to every live casino table operating this way.

Unibet's own live roulette tables are streamed from studios that undergo this same independent testing, so the wheel, the croupier's procedure and the settlement process match what a UK Gambling Commission licence requires. Some players prefer this format because they can watch the wheel and ball directly, and it sits alongside other live table games such as blackjack within a typical live casino lobby.

Special Variants: The Mechanics of Lightning Roulette

Lightning Roulette shows how does roulette work when a live dealer format gains an extra feature layered on top, without changing the fundamentals underneath. Developed by Evolution and available at UK Gambling Commission licensed live casinos, it uses the same 37-pocket European wheel, the same croupier procedure and the same bet types described throughout this guide.

The structural difference is a random number generator that, before each spin, selects between one and five numbers on the board as "Lightning Numbers" and assigns each one a multiplier. A Straight-Up bet that lands on one of these struck numbers pays the multiplied amount instead of the standard 35 to 1.

To fund this feature, the Straight-Up payout on non-struck numbers is reduced slightly, and the game's overall house edge sits a little above standard European Roulette as a result.

The wheel, the ball and the croupier's seven-step procedure still work exactly as described earlier: the multiplier is an overlay on the result, a layer added by software, and the core mechanics of roulette stay constant even as payout structures are adapted around them.

Understanding How Roulette Works

Every mechanic in this guide answers how does roulette work at every level: a precisely engineered wheel, a table layout that mirrors it, and a croupier who repeats an identical seven-step sequence on every round, whether you are playing European, French or American Roulette, online through certified software, or live with a real dealer and wheel.

That consistency is what keeps the game fair and auditable, spin after spin.

The zero, or zeros, give the house a fixed structural edge that no pattern of betting can remove, and every spin is independent of the one before it, so no amount of strategy changes the underlying odds.

Knowing the mechanics changes how you read the game: understanding why the wheel is built the way it is, and why the croupier's sequence never varies, makes it easier to follow a live table with confidence next time you sit down to play European, French or American Roulette at Unibet.

Frequently Asked Questions

How does roulette work?

In short, how does roulette work comes down to five stages: players place bets on the table layout, the croupier spins the wheel and releases the ball in the opposite direction, the ball loses momentum and settles into a numbered pocket, the result is announced and marked, and bets are settled before the next round begins.

How does a roulette wheel work?

The wheel is a balanced, near-frictionless wooden disc divided into 37 or 38 numbered pockets by metal separators. Its number sequence is deliberately non-sequential, alternating colour, high/low and odd/even values so that no visual pattern can be used to predict where the ball will land.

How does a roulette table work?

The table combines the wheel with a printed betting layout on green baize, arranged in three columns of 12 numbers plus the zero, surrounded by outside betting zones for dozens, columns and even-money bets. Chip colour marks which player owns a stack, and a marker on the table notes the value for higher denominations.

How does online roulette work?

Online roulette runs in one of two formats: RNG roulette, where certified software generates each independent spin, or live dealer roulette, where a real croupier spins a physical wheel on camera. Both formats operate under UK Gambling Commission licensing, which requires independent testing for fairness, and both use the same wheel layout and house edge as a physical table.

How does Lightning Roulette work?

Lightning Roulette uses the standard European wheel and croupier procedure, with a random number generator striking between one and five numbers before each spin and assigning them a multiplier. A winning Straight-Up bet on a struck number pays the multiplied amount instead of the usual 35 to 1.

What does the croupier do in roulette?

The croupier opens betting, spins the wheel, releases the ball, calls "no more bets" as the ball loses momentum, announces and marks the winning number once it settles, then clears losing bets and pays winning ones before the next round begins. Every step follows the same fixed sequence.

What is the house edge in roulette?

European Roulette carries a house edge of 2.7%, French Roulette around 1.35% on even-money bets under the La Partage rule, and American Roulette 5.26% because of its extra "00" pocket. This is a fixed mathematical advantage that no betting system or staking pattern can overcome over time.

Roulette is a game of chance. The house edge means that, over time, the casino holds a mathematical advantage on all bets. No betting system or strategy can change this. Please gamble responsibly. If you feel that gambling is affecting you or someone you know, free support is available at BeGambleAware.org or by calling the National Gambling Helpline.