The extra pocket that changes every bet you place
When you first look at an American roulette wheel, the double zero sits opposite the single zero, a green pocket marked 00. It looks like a small detail. It is not. That one extra pocket changes the arithmetic on every wager you can make, and understanding it is the difference between knowing what you are paying to play and guessing.
A European wheel has 37 pockets: the numbers 1 through 36, plus a single zero. An American wheel has 38: the same numbers, plus both a zero and a double zero. Both zero pockets are green. Neither belongs to red or black, odd or even, high or low. When the ball lands in either of them, most outside bets lose, and the inside bets that include zero pay only if you have placed a specific wager on that number.
What the double zero does to the odds
Roulette payouts are built as if the wheel had 36 pockets. A straight-up bet on a single number pays 35 to 1. If the wheel had 36 numbers, that payout would make the bet perfectly fair. The zero pockets are the house's margin. On a European wheel, the single zero creates a house edge. On an American wheel, the double zero adds a second house-favourable pocket, which makes the edge larger on every bet that does not specifically cover the zero.
The comparison below shows how the two layouts differ.
| Feature | European wheel | American wheel |
|---|---|---|
| Total pockets | 37 | 38 |
| Zero pockets | One (0) | Two (0 and 00) |
| Effect on outside bets | Lose on one green pocket | Lose on two green pockets |
| House edge on most bets | Lower | Higher |
| Common regions | Widely used outside North America | Common in North American venues |
The exact house-edge percentages are printed in the game's information panel or rules sheet where you play. What matters structurally is that the American layout gives the house two pockets instead of one, and that difference applies to every spin, regardless of what you bet or how long you have been at the table.
How the double zero interacts with each bet type
The double zero does not affect all bets equally, but it affects almost all of them. A straight-up bet on 00 pays the same 35 to 1 as a bet on any other single number. The difference is that 00 is one of two green pockets rather than one of 36 red or black numbers, so it sits outside the colour and parity bets entirely.
Outside bets such as red or black, odd or even, and high or low lose when the ball lands in either zero pocket. On an American wheel, that means two losing pockets instead of one. Inside bets that cover a range of numbers, such as a split or a street, only include the zero pockets if you deliberately place a wager that touches them. A bet on the first dozen, for example, covers 1 through 12 and loses on both zeros.
Some American tables offer a five-number bet covering 0, 00, 1, 2 and 3. It pays 6 to 1. Because the payout is calculated on a five-number block but the wheel has 38 pockets, this bet carries a higher house edge than most other wagers on the same layout. The table rules will state whether it is offered.
The sequence of a round, from buy-in to settlement
Knowing what the double zero means is one part of sitting down correctly. The round itself follows a fixed sequence, and the zero pockets sit inside that sequence rather than changing it.
You buy in at the table with cash or, at some venues, a cage voucher. The dealer exchanges it for roulette chips. These chips are often a distinct colour so the dealer can tell your wagers from another player's, and they carry no cash value away from the table. You place bets before the dealer calls an end to wagering. The ball is sent around the wheel in the opposite direction to the spin. When it settles in a pocket, the dealer marks the winning number, clears losing bets, and pays winners. Only after that does the next round open.
The two decision points that matter most are which bets you place and how much you stake on each. The layout does not change between spins. The double zero is always there, and it always counts.
What the double zero does not mean
A common misreading is that the double zero makes the wheel more likely to hit a green pocket on the next spin because one has not appeared for a while. It does not. Each spin is independent. The wheel has no memory, and the presence of two green pockets means there are two fixed positions among 38, not that the zeros become due.
Another misreading is that betting on 0 or 00 is a way to beat the layout. Both pay 35 to 1, the same as any other single number, and both carry the same house edge as any other straight-up bet on that wheel. Covering both zeros simply places two straight-up bets. It does not change the edge.
A third misreading concerns the five-number bet. Because it is the only wager on the American layout that covers a block not divisible into the standard payout structure, it is sometimes described as the worst bet on the table. The arithmetic supports that description, but the practical point is simpler: the edge on that bet is higher than on the others, and the rules sheet will confirm the figure where you play.
How to read the table before you sit down
The wheel itself shows you which layout you are facing. If there is a 00 pocket, you are on an American wheel. The table felt will also show the 00 position on the inside layout, and the outside boxes will be the same as any other roulette table. If the table offers the five-number bet, it will be marked on the felt.
Before you buy in, check the posted minimum and maximum for the table. Roulette tables carry different limits for inside and outside bets in some venues, and the dealer can tell you which applies. If you want to know the house edge for a specific bet, the game information panel or the venue's printed rules will state it. You do not need to calculate it yourself, but you should know that the American layout's edge is higher than the European layout's on the same bet type.
If you have a choice between a single-zero and a double-zero wheel in the same venue, the single-zero wheel carries the lower house edge on the bets that do not specifically cover the zero. That is a structural fact, not a strategy. It does not predict the next spin, and it does not promise a better session. It only means the built-in cost per wager is lower on the European layout.
Procedural mistakes new players make
The first mistake is treating the zero pockets as a side bet that somehow balances the rest of the layout. Placing a chip on 0 or 00 as insurance on a red or black bet does not protect the outside bet. The outside bet still loses on both green pockets, and the straight-up bet on the zero only pays if the ball lands on that exact pocket. You have simply placed two independent wagers.
The second mistake is not checking which wheel you are on before buying in. A player who has learned the single-zero layout and sits down at an American table without noticing the 00 is playing against a larger house edge without knowing it. The wheel is visible before you place a single chip. Look at it.
The third mistake is assuming the payout for a winning bet changes because the wheel has an extra pocket. It does not. A straight-up win pays 35 to 1 on both layouts. The extra pocket changes how often you can expect to win over a very large number of spins, not what you are paid when you do win. Those are different things, and the double zero lives in the first one.
FAQ
Is the double zero the same as the single zero?
No. The single zero and double zero are separate pockets, and they are positioned differently on the wheel. On an American layout, both are green and both sit outside the red and black outside bets, but they are distinct numbers with distinct positions. A bet on 0 does not win if the ball lands on 00.
Does the double zero change the payout on a winning number?
No. A straight-up bet on any single number, including 0 or 00, pays 35 to 1 on both European and American wheels. The extra pocket changes the probability of winning, not the payout ratio when a win occurs. The house edge rises because the same payout is paid against a wheel with one more losing pocket.
Why do some wheels have a double zero and others do not?
The single-zero layout is the older European format, while the double-zero layout became common in North American venues. Both are offered today, and the venue chooses which wheel to run. If you are unsure which layout you are looking at, check the wheel for a 00 pocket before you buy in.
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