Why does American roulette have two zeros?

Why American roulette has two zeros: the short answer

The double zero is not an American invention. It is a leftover from the French game, which used both a single zero and a double zero before anyone thought of dropping one. When roulette crossed the Atlantic, it arrived with both green pockets, and in the United States the layout simply stuck.

What changed was Europe. In 1843 the Blanc brothers opened a single-zero table at Bad Homburg to pull players away from rival casinos, and the single-zero wheel later became the main game at Monte Carlo. Most of Europe followed. The US kept the older format, which is why the American roulette wheel today has 38 pockets while the European roulette wheel has 37.

For a player, the history matters less than the maths. Both wheels pay exactly the same odds, so the extra green pocket is pure profit for the house. The rest of this page explains both parts, with figures, and you can find more answers like this on our casino questions hub.

Where the double zero came from: Paris in the 1790s

The earliest form of roulette was devised in 18th-century France. A novel published in 1796, La Roulette, ou le Jour, describes a wheel in the Palais Royal in Paris, which places the game firmly in the city’s gaming rooms by the end of that century.

According to the Wikipedia history of roulette (opens in a new tab), the wheels in Paris casinos in the late 1790s had a red single zero and a black double zero. Green came later, chosen for both zero pockets to avoid confusion with the ordinary red and black numbers. That colour story is covered on our page asking why zero is green in roulette.

So the original French wheel was, in effect, the wheel Americans still use: 36 numbers plus two house pockets. Calling it the American wheel is a modern label for a very old French design.

How the single zero split roulette in two

The break came in 1843, when the twins François and Louis Blanc introduced a single-zero wheel at Bad Homburg in Germany. Their reason was commercial: rival casinos used single and double zeros, and a game with one fewer house pocket was a better deal that could draw players away.

François Blanc went on to take over Monaco’s casino business in 1863, seven years after the principality’s first casino opened on 14 December 1856. The single-zero wheel became the premier game at Monte Carlo, and its reputation spread across Europe. Our Monte Carlo casino history and the wider history of roulette tell that story in full.

Why the double zero stayed in America

The French double-zero wheel made its way up the Mississippi from New Orleans, and while the single-zero wheel took over at Monte Carlo and beyond, the double-zero version remained dominant in the United States. It is still the standard there, and is also found in Canada, South America and the Caribbean.

No historical source records a single decision to keep the second zero. What can be said is that American operators had no competitive push to drop it in the way the Blancs did in Germany, and the extra pocket gave them a bigger margin on every bet. The arithmetic below shows how big.

Some casinos have gone further. A triple-zero wheel also exists, with 39 pockets including a green 000, and every bet on it carries a 7.69% house edge.

What two zeros do to American roulette odds

Every roulette bet is paid as if the wheel had 36 numbers. A straight-up bet pays 35 to 1, which would be a fair price if there were 36 pockets. Each zero added on top is a pocket that pays the house, so the edge grows with every green slot. You can see the full working on our roulette house edge page.

The double-zero figure is simply 2 divided by 38: two pockets out of 38 are not paid for. On a single-zero wheel the same sum is 1 divided by 37. Even-money bets show the gap too: red wins 18 times in 38 (47.37%) on an American wheel, against 18 in 37 (48.65%) on a European one. The standard house edge explanation works the same way for every casino game.

American against European roulette in pounds

Expected loss is stake multiplied by house edge, so the second zero is easy to price. The table assumes 60 spins an hour, a typical illustration rather than a fixed table speed, and £10 on each spin.

These are long-run averages, not predictions. A single session can finish well up or well down, but the more you play, the closer results tend to drift towards these figures. The La Partage rule on French tables halves the even-money edge, which is why it appears in the table as the cheapest option. The expected value page shows how these sums are built.

The five-number bet: a double-zero extra to avoid

The American layout adds one bet that exists only because of the second zero: the five-number or top line bet on 0, 00, 1, 2 and 3. It pays 6 to 1 and wins 5 times in 38 (13.16%).

Fair odds for five numbers out of 38 would be 33 to 5, or 6.6 to 1. Paying 6 to 1 instead gives an expected result of (5 × 6 − 33) ÷ 38 = −3/38, a 7.89% house edge. It is the single worst bet on the standard American table. Our basket and top line bet page compares it with the single-zero equivalents.

Myths about the double zero

• Myth: betting on the zeros gets round the edge. A straight-up bet on 00 wins 1 time in 38 and pays 35 to 1, exactly like any other number, so it carries the same 5.26% edge. Our answer on betting on zero explains more.
• Myth: the two zeros come up together or in patterns. Each spin is independent. Zero and 00 sit directly opposite each other on the wheel, and each lands 1 time in 38 on average.
• Myth: a betting system cancels the extra pocket. No staking plan changes the edge on the bets inside it. Simulations of Martingale play on a double-zero wheel still lost about 5.26% of everything staked.
• Myth: American tables pay more to make up for it. Payouts are identical on both wheels; only the number of pockets changes.

Double-zero roulette at UK online and live casinos

UK casinos mostly offer single-zero games, but American tables do appear. Evolution runs a live American Roulette (opens in a new tab) table with 0 and 00 on the wheel and layout, which its own page says has lower betting limits than its other roulette games, and its Auto Roulette range includes an American version. The Wizard of Odds roulette basics (opens in a new tab) give the full set of double-zero probabilities.

Before you stake anything, check which wheel you are on. These steps take a few seconds:

1. Open the game and look at the top of the betting layout for one green pocket or two.
2. Count the pockets on the wheel graphic or video: 37 means single zero, 38 means double zero.
3. Open the help or rules screen and find the stated RTP or house edge for each bet.
4. Look for French rules such as La Partage if you plan to bet on red, black, odd, even, high or low.
5. Choose the single-zero table if the same bet is available on both, since the payouts are identical.

Whichever wheel you choose, the UK’s game speed rules require at least 5 seconds per game cycle on casino games other than slots, autoplay is banned, and your net spend and time played must be shown in real time. Our verdict on whether European roulette is better than American sets out the comparison bet by bet.

Where to play roulette at UK casinos

None of our partner offers is built for roulette, so treat them as a separate question from which wheel to play. For roulette itself, look in each casino’s live and table game lobby for single-zero or French tables, and read the bonus terms before assuming any bonus applies there: table and live games are often excluded or count for less towards wagering, as our page on game weighting explains.

18+, new customers only, and full terms apply. Casumo gives a 50% bonus up to £100 on a first deposit of £20 or more, with opt-in required; the bonus must be wagered 10x within 7 days, bets are capped at £5 while it is active, and game, play and payment restrictions apply. 10bet matches 100% up to £25 when you choose the casino welcome bonus at sign-up and deposit within 7 days; wager the bonus 10x on slots within 3 days, maximum bonus winnings £1,000, and Skrill and Neteller deposits are excluded.

Coral runs a slot offer from 1 October 2026 to 1 February 2027: deposit and bet £10 or more on slots to get 100 free spins at 10p each on selected games, accept within 48 hours and use within 7 days, with no wagering on free spin winnings. Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards don’t qualify. Roulette, on any wheel, costs money over time, so set a budget first.

18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.