The part you are asking about has two names, and they describe different things
When someone asks what the roulette spinner is called, they are usually picturing the whole rotating assembly at the end of the table. That assembly is the wheel, or more precisely the wheelhead. The small white object the dealer sends travelling around the track is the ball. Separating the two matters because a question about the spinner can mean either, and the answer changes what you should look at next.
The wheelhead is the full rotating unit: the outer rim, the sloped track where the ball runs, the numbered pockets, and the central hub. On a physical table, the dealer spins the wheelhead in one direction and launches the ball in the opposite direction along the track. Gravity and friction slow the ball until it drops, strikes a deflector, and settles into one of the numbered pockets. The pocket the ball lands in is the winning number.
In an online or electronic game, there is no physical ball or wheelhead. The same sequence is generated by software, and the result is displayed as a spinning wheel animation. The terminology carries over: the display is still called the wheel, and the moving marker is still called the ball.
What a croupier does during a spin
The dealer who runs the game is the croupier. Their job during a spin is not to aim the ball at a number. They spin the wheelhead, launch the ball against its rotation, and then call the sequence of events: bets are open, no more bets, and finally the winning number and colour. On most tables the croupier also places the dolly, a small marker, on the winning number on the layout while losing bets are cleared and winning bets are paid.
The phrase "no more bets" is the procedural line that closes the round. After that call, no chips may be placed, moved, or removed. On a physical table, the call comes when the ball has slowed enough that the outcome is approaching. In an online game, the equivalent is a countdown timer that locks the betting area before the result is shown.
The wheel type is the single biggest rule difference between roulette tables
Before you sit down, identify which wheel is in front of you. The two standard layouts are not cosmetic variations; the extra pocket on one of them changes the house edge on every bet you can make.
| Feature | European wheel | American wheel |
|---|---|---|
| Number of pockets | 37 | 38 |
| Zero pockets | Single zero | Single zero and double zero |
| Number range | 0 to 36 | 0 to 36 plus 00 |
| Effect on house edge | Lower edge on the same bet type | Higher edge because of the extra pocket |
| Common where | Most tables outside the United States, and many online games | Common in the United States and some cruise-ship venues |
The extra double-zero pocket is not a separate game; it is an additional losing outcome for most bets. A bet that would lose on 0 also loses on 00, which is why the American layout carries a higher house edge for the same wager. When a venue offers both, the wheel type is printed on the layout or shown in the game information panel online.
How a round runs from buy-in to settlement
Roulette is a comparing game only in the loosest sense: you are not playing against another hand, but against the wheel's outcome. The sequence is fixed, and knowing it prevents most procedural mistakes.
You buy in at the table by placing cash on the layout. The croupier does not hand chips to you directly from hand to hand; they count the cash on the table, then push you a stack of roulette chips. These chips are colour-coded to you personally at that table. They have no value printed on them; their value is set by the buy-in amount divided by the number of chips issued. You cannot cash them at the main cage. They must be converted back to cash-value chips at the roulette table before you leave.
You place bets on the layout, which is the printed area beside the wheel. Inside bets sit on the number grid; outside bets sit around it. The croupier spins the wheelhead and launches the ball. At the call of no more bets, the layout locks. When the ball settles, the croupier marks the winning number, clears losing bets, and pays winners. Losing chips are swept first; winning chips are paid on top of the original stake, which stays on the layout until you collect it or the next round begins.
The main bet types and why their edges differ
Every roulette bet is a wager on where the ball will land, but the bets differ sharply in how often they win and how much they pay. A bet that covers more numbers wins more often but pays less; a bet on a single number wins rarely but pays more. The house edge is not the same across all of them, and the wheel type changes the arithmetic for each.
| Bet | What it covers | Payout | Edge on European wheel | Edge on American wheel |
|---|---|---|---|---|
| Straight-up | One number | 35 to 1 | Higher | Higher still |
| Split | Two adjacent numbers | 17 to 1 | Higher | Higher still |
| Street | Three numbers in a row | 11 to 1 | Higher | Higher still |
| Red or black | 18 numbers of one colour | 1 to 1 | Lower | Higher |
| Odd or even | 18 numbers | 1 to 1 | Lower | Higher |
| Column or dozen | 12 numbers | 2 to 1 | Lower | Higher |
The table uses relative terms because the exact percentages depend on the wheel type and, for some tables, on a rule variant such as la partage or en prison, which return part of a losing even-money stake when zero appears. The rule in force is printed on the table or stated in the game information panel. The structural point stands: the extra pocket on the American wheel raises the house edge on every bet type shown, and the inside bets that pay the most also carry the largest built-in disadvantage per wager.
What the wheel is not doing
A common misreading is that the wheel has a memory. It does not. Each spin is an independent event under the random number generator or the physics of the physical wheel. A number that has appeared five times in a row is no more or less likely to appear on the next spin than any other number, assuming a fair wheel. The same applies to colours and to sections of the wheel. The wheel does not become due for a black number after a run of reds.
What does vary is the wheel type you choose, the bets you place, how many spins you play per hour, and the size of each wager relative to your session budget. Those are the controls available to you. The built-in edge remains with the house on every bet, and no progression of stake sizes changes that arithmetic.
Procedural mistakes that cost new players time and money
The first mistake is buying in and then walking away from the table with colour chips still in hand. Those chips are worthless at the cage and at other tables. Convert them at the roulette table before you leave. The second is placing a bet after the no-more-bets call. On a physical table, a late hand over the layout will be waved off, and in an online game the timer simply locks. The third is assuming the wheel type does not matter. It does, on every spin. Check the layout or the information panel before the first bet, not after the first loss.
A fourth, less obvious mistake is mixing inside and outside bets without understanding that they settle differently. An outside bet such as red or black pays even money and covers 18 numbers. An inside straight-up bet pays 35 to 1 and covers one. Both can be placed in the same round, but they are separate wagers with separate edges and separate variance. The round settles them independently.
FAQ
Is the roulette spinner called a wheel or a wheelhead?
The whole rotating assembly is the wheel, and the technical term for the rotating unit itself is the wheelhead. The small object that travels around the track and lands in a pocket is the ball. In casual use, "spinner" usually means the wheel.
Does the croupier control where the ball lands?
No. The croupier spins the wheelhead and launches the ball, but the outcome is determined by the physics of the wheel and ball, or by the random number generator in an electronic game. The croupier's role is to run the round, call the phases, and settle bets.
Why does the wheel type change the odds?
Because the American wheel has an extra pocket, the double zero, which is an additional losing outcome for most bets. A European wheel has 37 pockets and a single zero. The extra pocket on the American layout increases the house edge on every bet type compared with the same bet on a European wheel.
If you or someone you know is struggling with gambling, help is available. Contact the National Problem Gambling Helpline for free, confidential support, available 24/7 in the US. Call the helpline printed in the footer below or visit ncpgambling.org. In the UK, call the National Gambling Helpline on 0808 8020 133 or visit begambleaware.org. Please gamble responsibly and only with money you can afford to lose.
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.