Two Wheels, Two Different Games
A roulette wheel with a double zero is not a minor variation. It is a different game with a different mathematical structure, and the moment you sit down you should know which one you are playing. The addition of the double zero did not happen on a single date in a single casino. It happened gradually, as roulette crossed the Atlantic and American operators modified the wheel to strengthen their position.
The standard European wheel has 37 pockets: the numbers 1 through 36, plus a single zero. The American wheel has 38 pockets: the same 36 numbers, a single zero, and a double zero. That one extra pocket changes the odds on every bet on the layout, and it is the reason the two games carry different house edges.
The Historical Route of the Double Zero
Roulette in its recognisable form emerged in France in the late 18th century, built around a wheel with a single zero. The zero was itself an innovation: it gave the house its mathematical advantage by creating a pocket that belonged to neither red nor black, neither odd nor even, neither high nor low. When the ball landed there, the house collected the losing outside bets.
As the game travelled to the United States in the early to mid-19th century, operators experimenting with the layout added a second zero pocket, often marked 00. The motivation was straightforward: an extra pocket that belonged to the house increased the share of each wager the operator could expect to keep over time. The double-zero wheel became the dominant format in American casinos and remains the standard layout in most venues in the United States today, while the single-zero wheel remained the norm in Europe and much of the rest of the world.
Some early American wheels went further, adding an eagle symbol or other house pockets. Those variants did not survive. The double-zero format did, and it is now the defining feature of what is called American roulette.
What the Extra Pocket Does to the Odds
The double zero is not a neutral addition. It changes the probability of every bet on the table. On a European wheel, a straight-up bet on a single number has 1 chance in 37 of winning. On an American wheel, the same bet has 1 chance in 38. The payout for that bet is unchanged, so the player is paid as if the wheel had 36 pockets while the wheel has one or two more.
House edge and RTP are complements: they sum to 100% for the same bet under the same rule set. The double zero increases the house edge because it adds a losing pocket without adding a corresponding payout. The exact edge depends on the bet, but the direction is consistent: every bet on the American layout carries a higher house edge than the equivalent bet on the European layout.
This is not a matter of the wheel being rigged. The wheel is doing exactly what its design says it will do. The extra pocket is a structural feature, printed on the layout and visible to every player before the first chip is placed.
Reading the Layout Before You Buy In
The first procedural step at any roulette table is to look at the wheel and the layout. The wheel itself shows the pockets: a single-zero wheel has 37, and a double-zero wheel has 38. The layout will also show the zero and, on an American table, the double zero at the head of the number grid. If you are playing online, the game information panel or help screen states the wheel type and the return-to-player percentage for the game as configured.
Some tables offer a rule called la partage or en prison, which applies to even-money outside bets when the ball lands on zero. Under la partage, the player loses only half the wager; under en prison, the wager is held for the next spin. These rules reduce the house edge on the affected bets. They are far more common on single-zero European tables, and their presence or absence is part of the specific rule set you should confirm before playing. A table with a double zero and no such rule is a different proposition from a single-zero table with la partage.
The Sequence of a Round
A round of roulette moves through a fixed sequence, and understanding it prevents most beginner mistakes.
First, the dealer or the online interface opens the betting window. You place chips on the layout. Inside bets go on the numbered grid or on the lines between numbers; outside bets go on the surrounding sections for red or black, odd or even, high or low, dozens, and columns. You may place multiple bets in the same round, and they are settled independently.
Second, the dealer closes the betting window. No chips may be placed or moved after this point. On a physical table, the dealer announces this; online, the interface locks the layout.
Third, the ball is released in the opposite direction to the spinning wheel. The ball loses momentum and settles into a pocket. The winning number and colour are announced and marked on the layout.
Fourth, the dealer or the software settles each bet. Losing chips are collected first, then winning bets are paid. Inside bets generally pay at higher multiples than outside bets because they are less likely to win. The payout for a straight-up bet is 35 to 1, a split is 17 to 1, a street is 11 to 1, and so on, regardless of whether the wheel has 37 or 38 pockets. That fixed payout schedule is exactly why the extra pocket matters.
Fifth, the dealer clears the layout and opens betting for the next round. Your chips remain your property until you colour up and leave the table.
Main Bet Types and How Their Edges Differ
Roulette bets fall into two broad groups: inside bets on specific numbers or small groups of numbers, and outside bets on larger categories. The payouts are fixed, but the probability of winning each bet differs, and so the house edge differs from bet to bet on the same table.
| Bet type | What it covers | Payout | How the double zero changes it |
|---|---|---|---|
| Straight-up | One number | 35 to 1 | 1 in 38 chance instead of 1 in 37; payout unchanged |
| Split | Two adjacent numbers | 17 to 1 | 2 in 38 instead of 2 in 37; payout unchanged |
| Street | Three numbers in a row | 11 to 1 | 3 in 38 instead of 3 in 37; payout unchanged |
| Red or black | 18 numbers of one colour | 1 to 1 | 18 in 38 instead of 18 in 37; zero and double zero lose |
| Odd or even | 18 numbers of one parity | 1 to 1 | Same structure; zero and double zero lose |
| High or low | 18 numbers in a range | 1 to 1 | Same structure; zero and double zero lose |
The table shows the pattern: the payout schedule is identical on both wheel types, but the probability of winning is lower on the American wheel because there is one more losing pocket. The house edge on any given bet is therefore higher on the double-zero wheel. The difference is not a secret and not a malfunction; it is the explicit design of the game.
Procedural Mistakes That Cost New Players
The first mistake is not checking the wheel type before buying in. A player who sits down assuming a single-zero wheel and bets accordingly is playing a different game from the one they think they are playing. The wheel is visible before the first chip is placed, and the game information panel online states the configuration. Read it.
The second mistake is placing late bets. Once the dealer calls no more bets, the layout is closed. Reaching across the table to adjust a chip after the call will get the bet refused at best and can be read as an attempt to alter a wager after the outcome is in motion. On a physical table, place your bets deliberately and keep your hands away from the layout once the ball is spinning.
The third mistake is misunderstanding what an even-money bet is. Red or black, odd or even, and high or low are called even-money bets because they pay 1 to 1, not because they have a 50% chance of winning. On a double-zero wheel, the two zero pockets mean the player has 18 winning numbers against 20 losing numbers on these bets. The payout is even; the probability is not.
What Strategy Charts Can and Cannot Do
Roulette does not have a basic-strategy chart in the way blackjack does, because the player makes no decisions after the bet is placed. The only decisions are which bets to place, how much to wager, and when to stop. Bet selection changes the house edge on the individual wager, but no selection of roulette bets turns a negative-expectation game into a positive one. The house edge on every roulette bet is built into the payout schedule and the wheel structure, and it remains in place on every spin.
What a player can control is the choice of wheel type, the choice of bet, and the pace of play. A single-zero wheel with la partage on even-money bets carries a lower house edge on those bets than a double-zero wheel without it. A straight-up bet carries a different edge from an even-money bet. The player who understands these differences can choose the game and the wager that suit their tolerance for variance and their expected rate of loss. That is the full extent of what strategy means at a roulette table.
FAQ
Why does American roulette have a double zero but European roulette does not?
The double zero was added by American operators in the 19th century as an extra house pocket. It increases the house edge on every bet because the payout schedule remains the same while the probability of winning falls. European wheels kept the original single-zero format.
Does the double zero change the payout for a winning number?
No. A straight-up bet pays 35 to 1 on both wheel types. What changes is the chance of winning: 1 in 38 on a double-zero wheel instead of 1 in 37 on a single-zero wheel. The payout is fixed while the probability moves, which is precisely how the extra pocket raises the house edge.
How can I tell which roulette wheel I am playing before I bet?
Look at the wheel itself or the layout. A double-zero wheel shows both a 0 and a 00 pocket, and the layout has both at the head of the number grid. Online, the game information panel or help screen states the wheel type and the return-to-player percentage. On a physical table, the wheel is visible before you buy in.
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