You are standing at the table and the wheel has either one green pocket or two
The question sounds simple, and the answer is, but the reason it matters is not about counting pockets. It is about the rate at which your money drains away. A roulette wheel has either one zero or two zeros, and that single pocket is the entire source of the operator's mathematical advantage on most bets. Before you buy in, you should know which wheel you are looking at, because the difference is not cosmetic.
A European wheel carries one zero. An American wheel carries a zero and a double zero. Both wheels also carry the numbers 1 through 36, so a European wheel has 37 pockets in total and an American wheel has 38. The zeros are green. The other numbers alternate red and black. That is the whole inventory, and everything else about roulette strategy and odds flows from it.
Why the zero is not just another number
Roulette pays winning bets as if the zero did not exist. A straight-up bet on a single number pays 35 to 1, but on a European wheel there are 37 pockets, not 36. On an American wheel there are 38. The gap between the payout odds and the true odds of the pocket landing is the house edge. The zero creates that gap, and the double zero widens it.
You can see this most cleanly on an even-money bet such as red or black. There are 18 red numbers, 18 black numbers, and the green zero or zeros. When the ball lands in a green pocket, most even-money bets lose outright on the American layout. The European layout often applies a rule called la partage or en prison that returns half the stake or holds it for the next spin on certain even-money bets, but that rule is not universal and you must check the table before relying on it. Without such a rule, the zero simply belongs to the house.
| Wheel type | Zero pockets | Total pockets | Effect on the player |
|---|---|---|---|
| European | 1 (single zero) | 37 | Smaller built-in advantage for the operator |
| American | 2 (zero and double zero) | 38 | Larger built-in advantage for the operator |
The extra pocket on the American wheel increases the house edge on the same bet. That is a structural fact, not a matter of table quality or dealer skill. If you have a choice between two wheels and the table minimums are the same, the European layout is the less expensive place to lose at the same rate of play.
The sequence of a round, from buy-in to settlement
You buy in by placing cash on the felt. The dealer does not take it from your hand; you set it down and the dealer exchanges it for colour chips that are yours alone at that table. These chips have no cash value away from the table, so you must convert them back before you leave. You cannot cash out colour chips at the cage.
Once you have chips, the round runs like this. The dealer closes betting, spins the wheel in one direction, and sends the ball around the outer track in the opposite direction. You may continue placing bets until the dealer calls no more bets, usually as the ball begins to slow. After the ball settles, the dealer marks the winning number with a dolly, clears losing bets, and pays winners. You do not touch your chips after the result is called. The dealer handles all payouts and removals.
Between spins, you place or move your own bets. You may not reach across the table to do so; each player manages the bets in front of them. When you are finished, you ask the dealer to colour you up, which means exchanging your colour chips for higher-value chips that the cage will cash.
What each decision point means
Roulette has fewer decision points than most table games, but each one changes the arithmetic of your session. The first decision is wheel selection. The second is bet selection. The third is stake sizing. The fourth is when to stop.
Bet selection is where most of the variation lives. An inside bet covers specific numbers or small groups. An outside bet covers broad categories: red or black, odd or even, high or low, dozens, columns. Inside bets pay more because they win less often. Outside bets pay less because they win more often, but they still lose at the house edge over time. No bet on the layout has a positive expectation for the player; the choice is only about how the losses are distributed between rare large hits and frequent small ones.
| Bet type | What it covers | Why players choose it |
|---|---|---|
| Straight-up | One number | Largest payout, rarest hit |
| Split | Two adjacent numbers | Moderate payout, moderate frequency |
| Street | Three numbers in a row | Broader coverage inside the layout |
| Corner | Four numbers meeting at a corner | Balanced inside bet |
| Red or black | 18 numbers of one colour | Most frequent wins, smallest payout |
| Dozen or column | 12 numbers | Middle ground between inside and even-money bets |
The house edge on a European wheel is the same for most bets on the layout: the zero pocket is the operator's share. The American wheel's second zero raises that share for the same bets. Some speciality bets, such as the five-number basket on an American layout that covers zero, double zero, one, two and three, carry a worse edge than the rest of the table. The takeaway is not that one bet is safe; it is that the wheel you choose matters more than the bet you choose for most of the layout.
Procedural mistakes that cost new players money
The first mistake is playing an American wheel when a European wheel is available at the same minimum. The second is not asking whether the table applies la partage or en prison on even-money bets, because those rules change what happens to your stake when the zero lands. The third is treating colour chips as cash and walking away from the table without colouring up. The fourth is placing a bet after the dealer has called no more bets, which will get the bet returned or rejected and can slow the whole table.
None of these mistakes changes the underlying mathematics, but they change the cost per hour and the smoothness of your session. Roulette is a game where the structure is fixed and the player's choices are narrow. The discipline is in choosing the cheapest structure available and managing the pace.
Strategy charts and why the rule set matters
Roulette does not have a strategy chart in the way blackjack does, because there is no decision that changes the odds after the bet is placed. What roulette has is a payout table and a wheel layout, and both are fixed by the version in front of you. Any published odds or house-edge figure for roulette assumes a specific wheel: 37 pockets or 38, with or without a la partage rule. A figure quoted without that context is not transferable to a different table.
The same principle applies to blackjack basic strategy, where published charts derive from the exact rule set in use: the number of decks, whether the dealer stands or hits on soft 17, and what doubling and splitting options the table allows. A chart built for one rule set is not correct for another. When you see a strategy chart, the first thing to check is the rule set it assumes, and the second is whether the table in front of you matches it.
FAQ
Does the zero count as red or black?
Neither. The zero and double zero are green, and on most layouts they lose for red, black, odd and even bets. Some European tables apply a rule that returns or holds the stake on even-money bets when the zero lands, but the zero itself is never a red or black result.
Can I bet on the zero itself?
Yes. The zero is a number like any other on the layout, and a straight-up bet on it pays at the same rate as a bet on any single number. It is not a special bet; it is simply one more pocket on the wheel.
Why would a casino offer a wheel with only one zero?
Because the single-zero wheel is the standard European format, and many venues outside the United States use it as their default. A venue chooses its wheel inventory based on its market and table mix, not as a favour to players. The single zero still gives the operator an edge on every bet.
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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.