Outside casino gambling, "roulette wheel" can refer to lottery wheeling systems, the fitness proportionate selection algorithm in computing, or the mathematical curve called a roulette. These are unrelated to the casino game.
Casino & Table Games
Roulette wheel
A roulette wheel is the numbered spinning device used in roulette. The dealer spins the wheel and a ball in opposite directions; the pocket the ball lands in determines the winning number.
Key points
- The roulette wheel is the central device in roulette; the ball's landing pocket decides which bets win.1
- An American wheel has 38 pockets (1–36, 0, 00); a European wheel has 37 pockets (0–36).2
- The croupier spins the wheel one way and the ball the opposite way; the ball eventually drops into a pocket.1
- The wheel itself has no fixed payout or house edge — those depend on the bet type and variant played.2
American vs European roulette wheel
| Feature | American wheel | European wheel |
|---|---|---|
| Total pockets | 38 | 37 |
| Zero pockets | 0 and 00 | Single 0 |
| House edge (even-money bets) | 5.26% | 2.70% |
| Number layout | Alternating red/black, 0 and 00 green | Alternating red/black, 0 green |
How the roulette wheel works
- The croupier spins the wheel in one direction, then spins the ball in the opposite direction along the wheel's outer rim.1
- As the ball loses speed, it falls from the rim onto the rotating wheel surface.2
- The ball bounces among the numbered pockets and eventually settles into one.1
- The pocket number becomes the winning number, determining which bets pay out.3
Common questions
What are the numbers on a roulette wheel?
On an American wheel, the numbers are 1 through 36 plus 0 and 00, making 38 pockets. On a European wheel, the numbers are 0 through 36, making 37 pockets. The numbers 1–36 alternate between red and black; 0 and 00 are green.2
What do numbers on roulette wheel add up to?
On a European wheel (0–36), the numbers add up to 666. On an American wheel (0, 00, 1–36), the sum is also 666, because 0 and 00 contribute nothing to the total of 1–36.1
What does the roulette wheel look like?
A roulette wheel is a horizontal spinning disc with numbered pockets around its edge. The pockets are coloured red, black, and green (for zeros). The numbers are arranged in a specific sequence, not in numerical order.1
Where this term is used
Not the same as
- Roulette wheel gambling — the broader activity or context of playing roulette, not the physical wheel
- 0 on roulette wheel payout — a bet-specific payout, not the wheel as an object
Related terms
Sources
- Roulette en.wikipedia.org Provides the definition, how the wheel works, and the sum of numbers.
- Roulette Basics – Rules, Bets, and Game Variations ... wizardofodds.com Supports the number of slots on American and European wheels and the ball drop mechanics.
- Biased roulette wheel: A Quantitative Trading Strategy Approach ar5iv.labs.arxiv.org Confirms that the pocket determines winning bets.
Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.