The wheel you will find on most Las Vegas floors
Walk up to a roulette table in Las Vegas and the wheel in front of you will almost always have 38 pockets. The numbers run 0 through 36, and then there is one more: a second green pocket marked 00, called the double zero. That is the defining feature of the American layout, and it is the single most important thing to understand before you put a chip down, because that one extra pocket changes the arithmetic of every bet on the table.
If you have seen a wheel with only 37 pockets, you were looking at a European-style single-zero layout. Both wheels share the same sequence of red and black numbers from 1 to 36, arranged in a specific order that alternates high and low, odd and even as evenly as the wheel allows. The difference is entirely in the green pockets: one zero on the European wheel, a zero and a double zero on the American wheel.
| Feature | European wheel | American wheel |
|---|---|---|
| Total pockets | 37 | 38 |
| Number range | 0-36 | 0-36 plus 00 |
| Green pockets | 1 (single zero) | 2 (zero and double zero) |
| Effect on straight-up bet | 1 winning number in 37 | 1 winning number in 38 |
| Effect on even-money bets | Zero loses all even-money bets | Zero and double zero both lose even-money bets |
The practical consequence is that every bet on the American wheel loses at a faster expected rate than the same bet on the European wheel. The double zero does not change how the game is played, but it changes what the game costs to play.
What the 38 pockets mean for a straight-up bet
Suppose you place a chip on a single number, say 17. On an American wheel there are 38 equally likely pockets, and exactly one of them pays you. If the game pays 35 to 1 on a winning straight-up bet, the shortfall between the true odds and the payout odds is where the house edge lives. The same bet on a European wheel has one fewer losing pocket, so the expected loss per wager is smaller even though the payout is identical.
This is the cleanest way to read any roulette table: the payouts are printed on the layout and they are the same on both wheel types, but the number of pockets that can beat you is not. A bet that pays 35 to 1 against 37 possible outcomes is a different proposition from a bet that pays 35 to 1 against 38 possible outcomes.
How a round runs in Las Vegas
You do not buy chips at the roulette table the way you would at a blackjack table. Roulette uses its own coloured chips, and each player at the table gets a distinct colour so the dealer can tell whose bets are whose. You buy in by placing cash on the felt, never handing it directly to the dealer. The dealer spreads the cash, announces the amount, and gives you a stack of non-value colour chips in return.
The sequence from there is straightforward. The dealer clears the previous round's losing bets and pays the winners. Players then place bets on the layout until the dealer calls no more bets. The ball is launched against the direction of the spinning wheel. When it drops into a pocket, the dealer places a marker on the winning number, clears the losing bets, and pays the winners in order. Only after the marker is removed can you place bets for the next spin.
Your colour chips have no value away from that specific table. When you are finished, tell the dealer you want to colour up, and they will exchange your colour chips for standard value chips at the cashier's cage.
The main bet types and where their edges differ
Every roulette bet is a wager on which pocket the ball lands in. What changes is how many numbers you cover and how much the bet pays. The inside bets sit on the numbered grid; the outside bets sit around its edges and cover larger groups. The key thing to understand is that the house edge on the American wheel is the same across almost every bet type, because the double zero is a losing pocket for all of them. What differs is how fast your money turns over and how the wins and losses are distributed.
| Bet | Numbers covered | Typical payout | What the double zero does |
|---|---|---|---|
| Straight up | 1 | 35 to 1 | Adds one more losing pocket |
| Split | 2 | 17 to 1 | Adds one more losing pocket |
| Street | 3 | 11 to 1 | Adds one more losing pocket |
| Corner | 4 | 8 to 1 | Adds one more losing pocket |
| Six line | 6 | 5 to 1 | Adds one more losing pocket |
| Red or black | 18 | 1 to 1 | Zero and double zero both lose |
| Odd or even | 18 | 1 to 1 | Zero and double zero both lose |
| High or low | 18 | 1 to 1 | Zero and double zero both lose |
The one exception on some American tables is a five-number bet covering 0, 00, 1, 2 and 3, which pays 6 to 1. It is the only bet on the layout with a materially worse expected return than the rest, because it covers five numbers but pays as if the odds were different. If you want to minimise expected loss per wager, that is the bet to avoid.
What the outside bets do
Outside bets cover broad categories: red or black, odd or even, the first 18 or the second 18, and the dozens or columns. They pay even money or 2 to 1, which means they win more often but pay less. The trade-off is that the two green pockets sit outside every one of these categories. When the ball lands in 0 or 00, every even-money outside bet on the table loses, and the 2-to-1 column and dozen bets lose as well.
This is why the American wheel's extra pocket matters more than it first appears. On a European wheel, a red or black bet has 18 winning pockets and 19 losing ones. On the American wheel it has 18 winning pockets and 20 losing ones. The payout has not changed, but the proportion of losing spins has.
The three procedural mistakes new players make
The first is trying to hand cash directly to the dealer. Roulette dealers cannot take cash from your hand; the cash goes on the felt, and the dealer will spread it and call out the amount before issuing colour chips. The second is leaving the table with colour chips in your pocket. They are worthless at the cage and at every other table, so you must colour up before you walk away. The third is reaching onto the layout after the dealer has called no more bets. Once the ball is in motion, the layout is closed, and touching chips after that point will get your hand pulled back and your bet ruled as it lay.
There is also a quieter mistake: assuming that because a number has not hit for a while it is more likely to hit next. Each spin is an independent event on a wheel with 38 equally likely pockets. The wheel has no memory, and no arrangement of past results changes the odds on the next spin.
Where the posted rules live
The table itself is your best source for what a specific Las Vegas table pays and how it is run. The minimum and maximum bet are printed on a placard at the table. The payout schedule is printed on the layout. If the table offers a rule variant, such as a different payout on the five-number bet or a rule about what happens to outside bets when a zero hits, it will be posted at the table or explained by the dealer. Ask before you bet, not after.
What no posted rule will tell you is the exact house edge for a given bet on that table, because the edge is not a policy; it is arithmetic. You can derive it yourself from two things you can see: the number of pockets on the wheel and the payout printed on the layout. The first is fixed by the wheel type, the second is printed in front of you, and the gap between the true odds and the payout odds is the edge.
FAQ
Why does a Vegas roulette wheel have 38 numbers instead of 37?
The extra pocket is the double zero, and it exists because the American-style layout adds it to the standard 0-36 sequence. It is not a different game; it is the same game with one additional losing pocket on every spin, which raises the expected cost of every bet compared with a single-zero wheel.
Can I find a single-zero wheel in Las Vegas?
Some venues do offer single-zero wheels, usually in higher-limit rooms, but the standard wheel on the main floor is the 38-pocket American layout. The wheel type is visible the moment you look at it: count the green pockets. One green pocket means 37 numbers, two green pockets means 38.
Do the zero and double zero count as red or black numbers?
No. The zero and double zero are green, and they sit outside every outside bet category. On an American wheel, a bet on red, black, odd, even, high or low loses when the ball lands in either green pocket, which is the main reason the double zero changes the expected return on even-money bets.
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