The wheel is a disc of numbered pockets, not a shape with sides
The question usually comes from someone looking at a roulette wheel for the first time and trying to describe it. A wheel is not a polygon with flat edges, so talking about sides is not quite the right frame. What the wheel has is a circular track divided into numbered compartments, called pockets, where the ball can land. The number of pockets is the figure that matters, and it is not the same on every wheel.
There are two main layouts in common use. A European wheel carries 37 pockets, numbered 0 through 36, with a single green zero. An American wheel carries 38 pockets, with the same numbers 0 through 36 plus an additional green double zero. The physical wheel and the betting layout both reflect that difference, and the extra pocket changes the arithmetic of every bet placed on the table.
What the two wheel types contain
Both wheels use the same core sequence of numbers, but the arrangement around the rim differs, and the American layout inserts the double zero into that sequence. The colours alternate red and black for the numbers 1 through 36, while the zero pockets are green on both layouts. A player looking at the wheel from across the table sees the same basic structure either way: a spinning disc, a ball track, and a set of numbered slots.
| Feature | European wheel | American wheel |
|---|---|---|
| Total pockets | 37 | 38 |
| Zero pockets | One (single zero) | Two (single and double zero) |
| Number range | 0-36 | 0-36 plus 00 |
| Colour of zero pockets | Green | Green |
| Effect on house edge | Lower than American for the same bet | Higher than European for the same bet |
The table above states the relationship without attaching a percentage, because the exact house edge depends on the specific bet and the rule set in force. What holds across every bet is that the American wheel's extra pocket increases the house advantage relative to the European wheel for the same wager. A player choosing between tables should treat the wheel type as a real decision point, not a cosmetic detail.
Why the extra pocket changes the odds
Roulette pays winning bets as if the zero pockets did not exist. A straight-up bet on a single number pays 35 to 1, but on a European wheel there are 37 possible outcomes, and on an American wheel there are 38. The payout does not adjust for the extra pocket, so the operator's mathematical advantage is built into the gap between the payout and the true odds.
This is the clearest way to understand house edge on roulette. The wheel gives the house more ways to win than the payout structure acknowledges. On a European wheel, the single zero creates that gap. On an American wheel, the double zero widens it. Every bet on the layout, from a single number to red or black, is priced against the same wheel, so the same principle applies across the table.
The sequence of a round from buy-in to settlement
Roulette is a table game with a fixed rhythm. A player buys in by placing cash on the table, never directly into the dealer's hand, and receives coloured chips that are unique to that player at that table. Those chips have no value printed on them; the dealer assigns their denomination at the buy-in and marks it on the table. When the player leaves, the coloured chips must be exchanged for standard casino chips at the table, because they cannot be redeemed at the cashier.
A round proceeds through clear stages. The dealer opens betting, players place chips on the layout, and the dealer then spins the wheel and launches the ball in the opposite direction. At a certain point the dealer calls no more bets, and from that moment no chip may be placed, moved, or removed. The ball slows, drops into a pocket, and the dealer marks the winning number on the layout with a marker called a dolly. Losing bets are cleared first, winning bets are paid, and only then may players touch their chips or place new wagers. Touching chips after the no-more-bets call is the most common procedural mistake a new player makes.
What each decision point means
Roulette offers no decisions during the spin itself. The ball is in motion, and the player has no action to take. Every decision happens before the spin, when the player chooses which bets to place. That makes roulette different from blackjack or craps, where players act at multiple points inside a round. In roulette, the entire strategic content is bet selection and stake sizing.
Bet selection matters because different bets on the same table carry materially different edges. The wheel type is fixed, but the payout structure varies by bet, and some bets expose the player to a larger house advantage than others. The player's task is to know what each bet pays, how many numbers it covers, and how those two figures compare. A bet that covers many numbers pays less; a bet that covers one number pays more. Neither changes the wheel, but each changes the rate at which the player's bankroll is expected to erode over time.
Main bet types and how their edges differ
Roulette bets fall into two broad groups: inside bets, placed on the numbered grid, and outside bets, placed on the surrounding sections for categories like red or black, odd or even, and high or low. Inside bets cover fewer numbers and pay more; outside bets cover many numbers and pay less. The table below compares the main wagers by coverage and payout, without attaching house-edge percentages that depend on the wheel and the operator's specific rules.
| Bet | Numbers covered | Payout | Where it sits on the layout |
|---|---|---|---|
| Straight up | 1 | 35 to 1 | Inside |
| Split | 2 | 17 to 1 | Inside |
| Street | 3 | 11 to 1 | Inside |
| Corner | 4 | 8 to 1 | Inside |
| Six line | 6 | 5 to 1 | Inside |
| Column or dozen | 12 | 2 to 1 | Outside |
| Red or black, odd or even, high or low | 18 | 1 to 1 | Outside |
The house edge on these bets is not uniform. On an American wheel, a bet covering five numbers exists on some layouts and carries a worse edge than most other wagers, because the payout does not scale with the coverage. The general principle is that the player should know the payout and the number of covered pockets before placing any chip, and should read the table's posted minimums and maximums, which vary by venue and by bet type.
Procedural mistakes that cost new players
The first mistake is treating coloured chips like cash. A player who walks away from the table with coloured chips has no way to redeem them elsewhere. The exchange back to standard chips must happen at the same table before leaving. The second mistake is touching or moving chips after the dealer has called no more bets. The call is final, and a chip that lands late or is moved after the call will be returned or, in some venues, forfeited. The third mistake is placing a bet without knowing whether the table uses a European or American wheel, and without knowing the minimum and maximum for that bet type. A player who sits down and bets first, then asks questions, has already made the most expensive decision available at a roulette table.
None of these mistakes changes the house edge, but they change how much the player loses through confusion rather than through the game itself. The procedural side of roulette is learnable in a few minutes, and it is worth learning before the first chip goes down.
FAQ
Does a roulette wheel have 36, 37, or 38 sides?
A wheel is not described in sides. It has pockets. A European wheel has 37 pockets, and an American wheel has 38. The numbers 1 through 36 appear on both; the difference is whether the wheel carries one zero or two.
Which wheel should a new player choose?
If the venue offers both layouts, the European wheel is the better choice for the same bet, because the extra double zero on the American wheel increases the house advantage. The player should confirm the wheel type before buying in, as the layout is usually printed near the wheel or on the table felt.
Can a player bet on the zero?
Yes. The zero is a number like any other on the layout, and a straight-up bet on it pays 35 to 1. On an American wheel, the double zero can also be bet as a single number, and some layouts offer a combined bet covering both zero pockets.
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