The green pocket that sits outside every even-money bet
A roulette wheel has one pocket that refuses to fit the neat categories players use for half the bets on the table. It is the zero, and on an American layout there are two of them. The question of whether zero is even or odd has a short answer and a longer one, and the longer one is where the actual game lives.
The short answer: zero is neither even nor odd. It is not a red number and it is not a black number. It is a green pocket that loses every even-money wager placed on the outside of the layout. When the ball lands there, red loses, black loses, even loses, odd loses, low loses and high loses. The casino sweeps all of those bets in a single spin.
That is not a quirk of numbering. It is the mechanism that gives the house its mathematical advantage on the most common bets in the game.
Why the wheel has a pocket that loses everything
A European roulette wheel has 37 pockets, numbered 0 through 36. An American wheel adds a second zero, the double zero, bringing the total to 38. The numbers 1 through 36 split evenly into 18 red and 18 black, 18 even and 18 odd. If those were the only pockets, a bet on red would pay even money against a true 50-50 chance, and the operator would earn nothing over time.
The zero pocket breaks that symmetry. A bet on red does not cover 18 losing pockets against 18 winning ones. It covers 18 winning pockets against 19 losing ones, because the zero is also a loss. The player is still paid even money, but the chance of winning is slightly less than half. That gap, repeated across thousands of spins, is the house edge on the even-money bets.
| Wheel type | Pockets | Zero pockets | Even-money bet covers | Even-money bet loses to |
|---|---|---|---|---|
| European | 37 | 1 (single zero) | 18 numbers | 19 numbers, including zero |
| American | 38 | 2 (single and double zero) | 18 numbers | 20 numbers, including both zeros |
The extra zero pocket on the American layout widens that gap further. It is the single clearest structural difference between the two wheels, and it is why the choice of wheel matters more than any betting pattern a player brings to the table.
What happens when the ball lands on zero
The moment the ball settles into the zero pocket, the croupier's routine is specific. All outside even-money bets are collected. Inside bets on the number zero itself are paid at the odds printed on the layout, which for a straight-up single-number bet is 35 to 1. Nothing else on the board is paid, unless the table rules include a special provision for zero.
Some European tables offer a rule called la partage or en prison. Under la partage, a losing even-money bet returns half the stake when zero appears. Under en prison, the stake is held on the layout for the next spin rather than collected immediately, and it is returned if the next spin wins. These rules reduce the cost of the zero pocket on even-money bets, but they do not remove it. The table layout and the posted rules state which provision, if any, applies.
On tables without such a rule, a zero simply loses every even-money bet in full. That is the standard outcome a player should expect unless the table visibly states otherwise.
How the zero changes the arithmetic of a session
Roulette is a negative-expectation game. That means the operator holds a mathematical advantage on every bet, and the zero pocket is a large part of how that advantage is built on the outside bets. The house edge and the return to player for the same bet under the same rule set sum to 100%. A rule that gives half the even-money stake back on a zero changes the edge on those specific bets, which is why the same game can carry different long-run costs depending on the wheel and the table rules.
None of this predicts a single spin. A player can win several even-money bets in a row, and a zero can appear twice in a short stretch. Variance describes how outcomes are distributed over time; it does not change the built-in edge. What a player controls is which wheel they sit at, which bets they place, how many spins they play, and how much they stake per spin.
Where zero sits among the other bet types
Roulette offers more than even-money bets, and the zero pocket affects each category differently. A straight-up bet on zero is an inside bet that pays 35 to 1, but its chance of landing is one in 37 on a European wheel. A split bet covering zero and one neighbouring number pays 17 to 1. A three-number bet covering zero, one and two pays 11 to 1. Each of these carries its own house edge, and the edges are not all the same.
| Bet type | What it covers | Payout | How zero affects it |
|---|---|---|---|
| Straight-up on zero | The zero pocket only | 35 to 1 | Wins when zero lands; loses otherwise |
| Split with zero | Zero plus one adjacent number | 17 to 1 | Zero is one of the two covered numbers |
| Street with zero | Zero, one and two | 11 to 1 | Zero is one of three covered numbers |
| Red or black | 18 coloured numbers | 1 to 1 | Zero loses the bet |
| Even or odd | 18 numbers of one parity | 1 to 1 | Zero loses the bet |
| Low or high | 1-18 or 19-36 | 1 to 1 | Zero loses the bet |
The lesson from the table is that zero is a losing pocket for the outside bets and a winning number only for the inside bets that specifically include it. A player who wants zero to work in their favour must bet on it directly, and that bet carries its own long-run cost.
Procedural mistakes new players make around zero
The first mistake is assuming zero is covered by an even-money bet because it feels like it should be. It is not. A player who bets on black and watches the ball land on zero has lost, and no argument at the table changes that. The second mistake is placing an even-money bet on an American wheel without realising the double zero is also a losing pocket. The two green pockets together mean the even-money bets lose to 20 numbers out of 38. The third mistake is chasing an even-money loss with a larger even-money bet on the next spin. A progression changes the size of the stake, not the probability of the next outcome. The zero pocket remains on the wheel for every spin, and it owes nothing to the previous result.
A player who wants the least costly even-money bets should look for a European single-zero wheel and check the posted rules for la partage or en prison. That is a rule-set decision, not a betting system, and it is the only choice at the table that changes the arithmetic of the zero pocket on the outside bets.
FAQ
Does zero count as an even number in roulette?
No. Zero is treated as neither even nor odd on a roulette layout. It is a green pocket that loses every even-money bet, including the even and odd wagers.
What happens to a bet on red or black when zero lands?
The bet loses in full unless the table rules include la partage or en prison. Under those rules, half the stake may be returned or the stake held for the next spin, depending on which provision the table uses.
Is betting on zero itself a good way to cover the even-money bets?
Betting on zero pays 35 to 1 when it lands, but it is a separate inside bet with its own house edge. It does not protect an even-money bet, and it loses on every spin where zero does not appear.
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