The single pocket that changes every payout
When you look at a roulette wheel, the zero is easy to miss. It is not red or black, it does not belong to the high or low half of the board, and on most layouts it sits at the top of the betting grid as its own separate box. But that one pocket is the reason the game is not a fair coin flip between the player and the house. It is the pocket that belongs to nobody, and it is the pocket that pays the operator over time.
On a European wheel there is one zero. On an American wheel there are two, a single zero and a double zero. The wheel itself is the physical or digital device that decides every spin, and the zero is simply one numbered compartment among the rest. What makes it different is not how it spins. It is what it does to the arithmetic of every bet on the table.
What the zero means for your bet
Every bet in roulette is a wager that the ball will land in a certain group of pockets. A bet on red wins if the ball lands in any red pocket. A bet on a single number wins if the ball lands in that exact pocket. The casino pays winning bets at odds that would be fair if the wheel contained only the pockets the bet covers. The zero is the extra pocket that is not covered by those outside bets, and it is the reason the payout does not quite match the true chance of winning.
Suppose you bet on red. On a European wheel, there are 18 red pockets and 18 black pockets. If those were the only outcomes, a red bet would be an even chance and an even-money payout would be exactly fair. But the wheel also has the zero. The ball can land in a pocket that is neither red nor black, and a red bet loses when it does. The payout has not changed. The chance of winning has. That gap, repeated over a very large number of spins, is the house edge.
The same logic applies to any outside bet. Odd, even, high, low, red, black: all of them lose to the zero on a European wheel, and to both zeros on an American one. The zero is not a special enemy of any one bet. It is the pocket that stands outside all of the even-money categories at once.
European and American wheels compared
Roulette wheels are not all built the same way, and the number of zero pockets is the single most important structural difference a player can read at a glance. The table below sets out what changes between the two common layouts.
| Feature | European wheel | American wheel |
|---|---|---|
| Total pockets | 37 | 38 |
| Zero pockets | 1 (single zero) | 2 (single zero and double zero) |
| Effect on even-money bets | Lose on the single zero | Lose on both zero pockets |
| Effect on straight-up bets | 1 winning pocket out of 37 | 1 winning pocket out of 38 |
| House edge on the same bet type | Lower | Higher |
The extra pocket on the American layout does not change the payouts. A straight-up number still pays at the same fixed multiple of the stake. What changes is how often the ball lands in a pocket that is not yours. The American wheel simply gives the house one more compartment that pays nobody.
What zero pays when you bet on it
The zero is also a number you can bet on directly. On most layouts it sits at the head of the grid, and a chip placed on it is a straight-up bet like any other single-number wager. It pays at the same fixed multiple of the stake as a bet on 17 or 24 or any other individual pocket. It has no special payout of its own.
Some tables also include announced or call bets that group the zero with neighbouring numbers on the wheel, but those are not part of the standard layout and their availability depends on the table rules. The zero's role in the game's arithmetic is the same whether you bet on it or against it. When you bet on it, you are simply backing one of the pockets that outside bets do not cover. When you do not, it is the pocket that quietly works against every even-money wager you place.
Where the house edge comes from
House edge and Return to Player are complements: they sum to 100% for the same game. In roulette, the edge is built entirely into the wheel's structure. The operator does not need to change payouts, rig spins, or do anything clever. The zero is the mechanism. Every bet on the table is paid as if the zero did not exist, and the zero exists on every spin.
This is why roulette is often described as a game of fixed odds. The player chooses which group of pockets to back, but the relationship between the payout and the true chance of winning is set by the wheel before the first chip is placed. No betting pattern changes that relationship. A player can choose a bet with a smaller built-in disadvantage, but the zero remains in the wheel for every bet and every spin.
It is also worth noting that different bets on the same table do not all carry the same edge. A straight-up bet and an even-money bet lose to the zero in different proportions, and a bet that covers many numbers behaves differently from one that covers few. The zero is the common factor, but the size of its effect depends on which bet you are making.
How to read a table before you sit down
The first thing to check is the wheel itself. A single zero means one set of odds. A double zero means another. The table layout usually mirrors the wheel, so the zero boxes on the felt tell you the same thing. If the layout shows both a 0 and a 00, you are looking at an American-style game. If it shows only a 0, it is a European-style game. Some venues offer both, and the difference is visible before you place a single chip.
The second thing to check is the table minimum and maximum, which are printed on the layout or on a sign at the table. The zero does not change these, but they determine the smallest and largest stake you can place on any bet, including a straight-up bet on the zero itself. If you plan to bet the zero directly, make sure the table minimum applies to the bet you want to make.
The third thing to understand is that the payout for each bet type is fixed and printed on the layout or in the game's information panel. You do not need to memorise the odds before you play. You need to know that the payouts are the same whether the wheel has one zero or two, and that the difference between the two games is in how often the ball lands in a pocket that pays no one.
Procedural mistakes new players make
The most common mistake is treating the zero as a colour. It is not red, not black, and not part of any even-money category. A player who bets on black and sees the ball land in the zero has not been cheated; the bet simply lost to the pocket that stands outside the black and red split. The same is true for odd and even. The zero is not an odd number in the context of the outside bets, and it does not belong to the low or high half of the board.
A second mistake is assuming the zero pays more than other single numbers. It does not. A straight-up bet on the zero pays the same fixed multiple as a straight-up bet on any other number. The zero is special because of its effect on the outside bets, not because of its own payout.
A third mistake is placing a bet without checking which wheel is in use. A player who has read about European roulette odds and then sits at an American table has walked into a different game with a higher built-in edge on the same bets. The wheel itself is the first piece of information to read, and it is visible from across the room.
FAQ
Does the zero count as red or black?
No. The zero is its own pocket, usually green on the wheel and the layout. It is not part of the red or black categories, and any bet on red or black loses when the ball lands in the zero. On an American wheel, both the zero and the double zero sit outside the colour bets.
Is betting on zero a good way to cover the outside bets?
Betting on the zero alongside an outside bet reduces the number of losing pockets for that spin, but it does not remove the house edge. The zero bet has its own payout and its own chance of winning, and the two bets together still leave the house with the same structural advantage on each wager. It changes the shape of your outcomes, not the long-run arithmetic.
Why do some wheels have two zeros?
The double zero is a feature of the American layout. It adds one more pocket to the wheel, which increases the house edge on every bet because the payouts stay the same while the chance of winning falls. The two-zero wheel is simply a different game structure, and the extra pocket is visible on the layout before you play.
Gambling can be addictive. If you or someone you know is struggling, call the helpline printed in the footer below for confidential support, or visit a responsible gaming resource in your area. Please play responsibly and within your limits.
Play responsibly
Gambling should be treated as paid entertainment, never as a way to earn income or recover losses. 1-800-MY-RESET (1-800-697-3738)
18+ or 21+ depending on where you are; follow the minimum age that applies to you.
This article is general information about how these mechanics work. It is not legal advice and not a recommendation to gamble or to use any particular operator. Availability and legality differ by jurisdiction — check the rules that apply where you are.