Annabel walks you through the three wheels you'll meet in London, and the one to avoid.
Roulette rules and variants
Annabel Cavendish
Editor · 14 May 2026
The Wheel Is the Whole Story
Start with the hardware, because everything flows from it.
A European roulette wheel has 37 numbered pockets: zero through 36. An American wheel has 38, because someone in the 19th century added a second zero, marked double-zero, which increased the house's take without requiring any other change to the game. The house edge on a European wheel is 2.70% on every bet you can place. The house edge on an American wheel is 5.26% on almost every bet. If you sit down at an American wheel by mistake, you're paying roughly double for the same entertainment. That's not a subtle difference.
The 37-pocket geometry produces its house edge through the payout structure. A straight-up bet pays 35 to 1, but the fair payout on a 1-in-37 event would be 36 to 1. The casino keeps that one pocket's worth, which is 1/37 of everything wagered, or 2.703% to be precise. According to our roulette basics analysis, this fraction applies identically to every bet on the table: straight-ups, splits, streets, corners, columns, dozens, red, black, odd, even, high, low. Every single one. It's an algebraic identity baked into the payout structure.
The American 38-pocket wheel produces a different fraction: 2/38, which simplifies to 5.26%. The casino keeps two pockets' worth instead of one.
The Year London Had No House Edge
Here is the part most histories leave out entirely.
On 30 December 1967, Scotland Yard warned London casino operators that any roulette wheel containing a zero might be prosecuted under the Betting and Gaming Act 1960, following a House of Lords ruling that the zero made roulette a game of unequal chance. The implication was remarkable. For roughly a year, legal London roulette was played on zero-free wheels. No zero means no house edge on even-money bets. The casino was effectively hosting a fair coin flip. As The Conversation reported in December 2017, this brief period was the most mathematically favourable version of the game ever offered in a licensed casino.
The Gaming Act 1968 resolved the situation by explicitly permitting the modest house edge as part of the licensing compact that governs every London table today. Every time you sit at a single-zero wheel in this city, you're sitting at the product of that parliamentary compromise.
The reason London settled on single-zero while parts of America kept double-zero is almost entirely a matter of which era of casino regulation applied where and when. The European game is older; the American wheel's double-zero is an inheritance from early gambling parlours where operators added the extra pocket because they could, and customers didn't know enough to object.
Where to Find What in London
The live London Mayfair casinos currently operating are Les Ambassadeurs at Hamilton Place, The Hippodrome, Wynn Mayfair (formerly Aspinall's, acquired by Wynn Resorts in early 2025) at 27-28 Curzon Street, Park Tower, Crown Aspers, Colony Club, and Palm Beach. Two famous rooms are no longer with us: Crockfords closed permanently in October 2023 after 195 years at 30 Curzon Street, and the Ritz Club closed in May 2020. If you arrive at either address expecting a casino, you will be disappointed.
The practical consequence for London play is this. Empire Casino at Leicester Square runs American double-zero roulette exclusively and explicitly says so in its house rules. That is 5.26% house edge regardless of how you bet. The address does not improve the mathematics.
Most London casinos, even those running single-zero European wheels, don't apply La Partage or En Prison rules on the floor. La Partage halves the house edge to 1.35% on even-money bets when zero lands. Aspers at Westfield Stratford is one of the few UK land-based casinos that publicly confirms La Partage on its European tables. A player who knows to ask for it there is playing a materially better game than a player at any standard London European table, let alone an American one.
The Wheel Manufacturers
The two names that matter on any serious casino floor are Cammegh and TCS John Huxley.
A Cammegh Mercury 360 uses four in-rim sensors and an open data protocol; the casino can pipe the results directly into its own analytics. The Continental, Cammegh's heritage wheel with a shallower ball track and deeper pockets, is what you'd find in a Monte Carlo salon, and it behaves differently to a Mercury 360 in ways worth knowing if wheel physics interests you. The TCS Saturn uses three sensors and has proprietary Drop Zone Detection built in, outputting to TCS's own console.
The practical difference for you as a player: both systems are logging every spin and watching for statistical anomalies. The days of exploiting an unmonitored wheel are well and truly over at any venue running modern hardware.
The Ivey Test and What It Means for Roulette Players
There is one court case worth knowing because it reshaped English law considerably.
In August 2012, the poker player Phil Ivey and his partner sat down at Crockfords on Curzon Street, played Punto Banco over two days, and left with £7.7 million. The casino refused to pay. The case went to the UK Supreme Court, reference UKSC 67, and the ruling came in 2017. Ivey lost. Lord Hughes concluded that Ivey had staged a carefully planned sting, having instructed the croupier to orient cards in a way that gave him information asymmetry. The ruling simultaneously exonerated his subjective belief that he wasn't cheating and declared his conduct legally cheating anyway. As the BBC reported in October 2017, it also replaced the old Ghosh test for criminal dishonesty in English and Welsh courts. The Ivey test is now the standard across fraud, theft, and related offences. One game of Punto Banco rewrote dishonesty law for the whole jurisdiction. Crockfords itself has since closed.
The point for any roulette player: information asymmetry is not a defence in a UK casino context, and the casino is under no obligation to pay you while the lawyers argue about it.
Welcome to the lesson on roulette rules and variants.
I'm Annabel, and before we get into systems, edges, and all the genuinely interesting mathematics to come in later lessons, I think it's worth spending a moment on how the game actually works, how it got here, and why not every roulette table in the world is the same proposition.
Let's start with the wheel, because the wheel is the whole story.
A European roulette wheel has thirty-seven numbered pockets: zero through thirty-six.
An American wheel has thirty-eight, because someone in the nineteenth century decided to add a second zero, marked double-zero, which increased the house's take without requiring any other change to the game.
The house edge on a European wheel is two point seven percent on every bet you can place.
The house edge on an American wheel is five point two six percent on almost every bet you can place.
If you sit down at an American wheel by mistake, you are paying roughly double for the same entertainment.
This is not a subtle difference.
Now, here is the part that most histories leave out.
For a brief period in late 1967 and into 1968, roulette in London was, from a mathematical standpoint, the most favourable version of the game ever offered in a licensed casino.
Scotland Yard had warned London operators that any wheel containing a zero might be prosecuted under the Betting and Gaming Act 1960, following a House of Lords ruling that the zero made roulette a game of unequal chance.
The implication was remarkable: legal London roulette, for roughly a year, was played on zero-free wheels.
No zero means no house edge on even-money bets.
The casino was effectively hosting a fair coin flip.
The Gaming Act of 1968 resolved the situation by explicitly permitting the modest house edge as part of the licensing compact that governs every London table today.
Every time you sit at a single-zero wheel in this city, you are sitting at the product of that parliamentary compromise.
The reason London settled on single-zero, while parts of America kept double-zero, is almost entirely a matter of which era of casino regulation applied where and when.
The European game is older; the American wheel's double-zero is an inheritance from early gambling parlours where operators added the extra pocket because they could, and customers didn't know enough to object.
The practical consequence for you, sitting in London today: the Empire Casino at Leicester Square runs American double-zero roulette and explicitly says so in its house rules.
If you happen to be nearby and fancy a spin, know that you are paying five point two six percent house edge rather than two point seven.
That is a meaningful difference.
The address does not improve the mathematics.
What's also worth knowing: most London casinos, even those running single-zero European wheels, do not apply La Partage or En Prison rules on the floor.
La Partage, which we cover in its own lesson, halves the house edge to one point three five percent on even-money bets when zero lands.
Aspers at Westfield Stratford is one of the few UK land-based casinos that publicly confirms La Partage on its European tables.
A player who knows to ask for it there is playing a materially better game than a player at any standard London European table, let alone an American one.
The wheel manufacturers are worth knowing about, because they shape what you are actually sitting at.
The two names that matter on any serious casino floor are Cammegh and TCS John Huxley.
A Cammegh Mercury 360 uses four in-rim sensors and an open data protocol; the casino can pipe the results directly into its own analytics.
A TCS Saturn uses three sensors and has proprietary Drop Zone Detection built in at no extra cost, outputting to TCS's own console.
The practical difference for you as a player is that both systems are logging every spin and watching for statistical anomalies.
The days of exploiting an unmonitored wheel are well and truly over at any venue running modern hardware.
The Continental, Cammegh's heritage wheel with a shallower ball track and deeper pockets, is the one you'd find in a Monte Carlo salon, and it behaves rather differently to a Mercury 360 in ways we will discuss when we get to wheel physics.
There is one court case worth knowing about, because it reshaped English law considerably.
In August 2012, the poker player Phil Ivey and his partner sat down at Crockfords on Curzon Street, played Punto Banco over two days, and left with seven point seven million pounds.
The casino refused to pay.
The case went to the UK Supreme Court, reference UKSC sixty-seven, and the ruling came in 2017.
Ivey lost.
Lord Hughes concluded that what Ivey had done was stage a carefully planned sting, having instructed the croupier to orient the cards in a way that gave him information asymmetry.
The ruling simultaneously exonerated his subjective belief that he wasn't cheating and declared his conduct legally cheating anyway.
It also, as a bonus, replaced the old Ghosh test for criminal dishonesty in English and Welsh courts.
The new Ivey test is now the standard across fraud, theft, and related offences.
One game of Punto Banco rewrote dishonesty law for the whole jurisdiction.
Crockfords itself has since closed, permanently, in late 2023, after a hundred and ninety-five years.
The address was thirty Curzon Street.
A sign on the door directs former members to the Colony Club at twenty-four Hertford Street.
The point for any player, roulette or otherwise, is that information asymmetry is not a defence in a UK casino context, and the casino is under no obligation to pay you while the lawyers argue about it.
So.
Know your wheel.
Know your variant.
Know your edge.
And if anyone invites you to play American roulette in a basement when a European table is available upstairs, you now know which staircase to use.
