Thirty-eight pockets, and one of them changes the maths
You sit down at a roulette table in the United States, buy in, and look at the wheel. Counting the numbered slots is the first thing most players do, and the count is straightforward: a US roulette wheel has 38 pockets. Numbers 1 through 36 alternate red and black, and then two green pockets sit apart from that sequence: a single zero and a double zero. Those two green slots are the reason a US wheel plays differently from the European layout most online casinos also offer.
The presence of the double zero does not change how a spin works. The ball still lands in one pocket, the dealer still settles every bet the same way, and your number still pays 35 to 1 when it hits. What the extra pocket changes is the rate at which the house edge collects over time. On a wheel with 37 pockets, the zero represents one losing slot for most outside bets. On a US wheel with 38 pockets, two slots do that work. The game does not become harder to understand; it becomes slightly more expensive to play, measured over many spins.
Reading the wheel and the table together
The wheel and the betting layout are two views of the same set of numbers, arranged differently. The wheel arranges pockets around a physical circle. The table layout arranges the same numbers in a grid, with outside betting areas around it. A player who only reads the wheel misses where the bets go; a player who only reads the layout misses how the ball's landing position maps to a payout.
On the layout, inside bets sit on individual numbers or small groups of them. Outside bets sit in the boxes around the grid and cover large sections: red or black, odd or even, high or low, columns, and dozens. Every one of those bets is settled against the same 38-pocket wheel, which is why the double zero matters to all of them, not just to bets placed on zero itself.
When you approach a US roulette table, the posted minimum and maximum apply to the total you place per spin, not per chip. The dealer or the electronic display will state the table limits. Before the ball is released, you place chips on the layout. Once the dealer calls no more bets, the layout is frozen until the ball settles and losing bets are cleared.
How a round moves from buy-in to settlement
You exchange cash for roulette chips at the table. Roulette chips are typically colour-coded per player so that two people betting on the same number can be told apart; they cannot be used at other tables and must be exchanged back for cash chips before you leave. Some electronic or hybrid tables use a credit balance instead, but the sequence of a round is the same.
The dealer opens betting, the ball is spun in the opposite direction to the wheel's rotation, and players place bets until the dealer closes the round. The ball drops into a pocket, the dealer places a marker on the winning number, losing bets are swept, and winning bets are paid. Inside bets on a single number pay 35 to 1; the payout reflects the odds against a single pocket on a 38-pocket wheel, not a fair return on the bet.
After settlement, the marker is removed and the next round begins. Nothing carries over from the previous spin. A number that has just hit is no more or less likely to hit again, because each spin is an independent event on the same physical wheel.
What the two zeros do to each bet
Every roulette wager is a negative-expectation bet. The house edge comes from the gap between the payout and the true odds. On a US wheel, that gap is wider than on a single-zero wheel for most bets because there are 38 possible outcomes while the payouts are built around a smaller set of winning numbers.
Consider an even-money bet such as red. On a US wheel, 18 red numbers win and 20 pockets lose: 18 black numbers plus the zero and double zero. On a European wheel, 18 red numbers win and 19 pockets lose. The payout is the same, but the proportion of losing pockets is higher on the American layout. The same logic applies to odd or even, high or low, and the outside bets generally.
| Wheel type | Pockets | Zero pockets | Winning red numbers | Losing pockets on a red bet |
|---|---|---|---|---|
| European | 37 | 1 | 18 | 19 |
| US | 38 | 2 | 18 | 20 |
The difference does not mean a US wheel is rigged or that the ball is steered. It means the game's arithmetic charges a higher expected loss per unit wagered. A player choosing between the two layouts is choosing between two different rates of loss, not between a fair game and an unfair one.
Inside bets, outside bets, and the edge they carry
Roulette offers a wider menu of bets than most table games, and the house edge is not identical across all of them. On a US wheel, most standard bets share the same structural disadvantage, but a few special bets carry a worse one because their payouts are built on a different scale.
Inside bets cover single numbers and small groups. A straight-up bet on one number pays 35 to 1. A split covers two numbers and pays 17 to 1. A street covers three numbers and pays 11 to 1. A corner covers four and pays 8 to 1. A six-line covers six and pays 5 to 1. Each of these payouts is lower than the true odds against the bet, and that gap is the house edge.
Outside bets cover large sections and pay closer to even money. Red or black, odd or even, and high or low each pay 1 to 1. Columns and dozens each pay 2 to 1. The five-number bet, available only on a US layout, covers 0, 00, 1, 2, and 3 and pays 6 to 1. That bet carries a materially higher house edge than the rest of the table because five numbers are covered while the payout is structured as if fewer were.
| Bet | Numbers covered | Payout | Relative edge on a US wheel |
|---|---|---|---|
| Straight-up | 1 | 35 to 1 | Standard |
| Split | 2 | 17 to 1 | Standard |
| Street | 3 | 11 to 1 | Standard |
| Corner | 4 | 8 to 1 | Standard |
| Six-line | 6 | 5 to 1 | Standard |
| Red or black | 18 | 1 to 1 | Standard |
| Column or dozen | 12 | 2 to 1 | Standard |
| Five-number (0, 00, 1, 2, 3) | 5 | 6 to 1 | Higher |
No bet on the layout turns the edge in the player's favour. Choosing a standard bet over the five-number bet changes the expected rate of loss, but the house still holds an advantage on every spin. The choice is about how much of your session bankroll you expose per unit wagered, not about finding a winning position.
Strategy charts do not exist for roulette, and that is the point
Some table games publish strategy charts: blackjack basic strategy derives from the exact rule set in use, including deck count, dealer stand rules, and doubling and splitting permissions. Roulette has no equivalent. There is no decision that changes the composition of the wheel, and no bet that alters the payout table. The only decisions are which bets to place, how much to stake, and when to stop.
That does not make roulette a thoughtless game. It makes it a game where the thinking happens before the spin rather than during it. A player who understands that the five-number bet is worse than the rest of the table can avoid it. A player who understands that the double zero widens the gap on every outside bet can choose a single-zero layout when one is available. A player who understands that each spin is independent can ignore the display of recent numbers, which records what happened and predicts nothing.
Betting systems that change stake size after wins or losses do not change the underlying arithmetic. Doubling after a loss increases the size of the next wager; it does not change the probability that the next spin lands on a losing pocket. Such systems redistribute outcomes across a session, creating many small wins and occasional large losses, but the expected loss per unit wagered stays the same.
Procedural mistakes that cost new players before the ball drops
The first mistake is treating roulette chips as cash. Roulette chips are table-specific and must be exchanged at the table before you leave. Walking away with them means carrying chips that no other table will accept. The second mistake is betting after the dealer calls no more bets. Late bets are void or returned, and repeatedly placing them slows the table and draws attention. The third mistake is misreading the table minimum. On many US tables, the minimum applies to the total outside and inside wager combined, not to each individual chip, so a player who spreads chips across the layout can accidentally wager far more than intended.
A fourth mistake is chasing a number because it has not appeared recently. The wheel has no memory, and the probability of any given pocket on the next spin is the same on every spin. The display of recent numbers is a record, not a forecast. A fifth mistake is placing the five-number bet without realising it carries a higher edge than every other standard wager on the table. Knowing the layout well enough to avoid it is one of the few genuine advantages a roulette player can hold.
Where the numbers are posted if you want to verify them
The wheel itself is the primary source. A US wheel shows 0, 00, and 1 through 36, and the double zero pocket is the visual difference from a single-zero wheel. The table layout repeats the same numbers, with the five-number bet area unique to the American arrangement. If a game is electronic, the information panel or help screen states the wheel type and the payout table. The operator's game rules page usually states whether a roulette title uses a single-zero or double-zero layout, and that single detail tells you which arithmetic applies to every bet on the table.
No document at the table will state the house edge as a percentage. What the layout and the payout table give you is enough to work it out: the number of pockets, the number of winning pockets for each bet, and the payout. The gap between the payout and the true odds is the edge, and on a US wheel the double zero widens that gap on every standard bet.
FAQ
Does a US roulette wheel have 37 or 38 numbers?
A US roulette wheel has 38 numbered pockets: 1 through 36, plus a single zero and a double zero. A European wheel has 37 pockets because it carries only the single zero.
Why does the double zero matter if I never bet on it?
The double zero matters even when you never bet on it because it is an additional losing pocket for most outside bets and for any inside bet that does not include it. Its presence changes the proportion of losing outcomes on every spin.
Is the five-number bet available on every roulette table?
The five-number bet covering 0, 00, 1, 2, and 3 is specific to the American layout. It is not available on a single-zero wheel, and where it is offered it carries a higher house edge than the other standard bets, so it is worth identifying before you place chips.
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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.