European vs. American Roulette: Why That One Extra Zero Changes Everything

By Alex Bennett · Updated 12 August 2026

When stepping up to a roulette table, whether online or in a bustling casino, the choice between European and American variants might seem subtle. However, the presence of a single zero versus a double zero—the ‘0’ and ’00’—is far from a minor detail. This seemingly small difference fundamentally alters the game’s mathematical structure, significantly impacting player odds, house edge, and optimal betting strategies. Understanding this distinction is crucial for any player aiming to minimize losses and maximize potential wins in this classic casino game.

The Core Difference: A Tale of Two Zeros

At its heart, roulette is a game of chance played on a wheel with numbered pockets and a betting layout. The fundamental objective is to predict where a small ball will land after being spun around the wheel. The most significant divergence between the two primary versions of roulette lies in the wheel’s composition. The European roulette wheel features 37 pockets: numbers 1 through 36, all colored either red or black, plus a single green ‘0’ pocket. Conversely, the American roulette wheel expands this to 38 pockets, incorporating the same 1-36 red and black numbers but adding both a green ‘0’ and an additional green ’00’ pocket. This addition of the double zero is not merely an aesthetic change; it directly influences the house’s statistical advantage.

The consequence of this single extra pocket cannot be overstated. In European roulette, where there is only one zero, the house edge is a relatively modest 2.70%. This means, on average, for every $100 wagered, the casino expects to retain $2.70 over the long run. This figure is calculated based on the probability of winning various bets. For instance, a bet on a single number pays 35 to 1. On a European wheel, there are 37 possible outcomes. If you bet $1 on a single number, you win $35 if it hits, but lose your $1 stake if it doesn’t. The expected value (EV) for a single number bet on European roulette is approximately -0.027 or -2.7%.

Contrast this with American roulette. The introduction of the ’00’ pocket increases the total number of outcomes from 37 to 38. While many common bets, like betting on red or black, odd or even, or high or low (1-18 or 19-36), still pay 1 to 1, their probability of winning is now diluted by the presence of two zero pockets. On an American wheel, a single number bet still pays 35 to 1, but there are 38 possible outcomes. This significantly increases the house edge to approximately 5.26%. For every $100 wagered, the American casino expects to keep $5.26. This means players generally face a steeper challenge when playing American roulette, making the European version statistically more favorable.

Impact on Betting Strategy and Player Odds

The disparity in house edge directly translates into differing strategic considerations for players. Knowing that the European vs American roulette wheel offers better odds is the first step towards a more informed approach. In European roulette, with its lower house edge of 2.70%, players have a statistically better chance of long-term profitability, or at least, slower erosion of their bankroll. This makes it the preferred choice for serious players who focus on maximizing their win potential and minimizing their risk.

For instance, consider the “even money” bets—betting on red or black, odd or even numbers, or the low (1-18) or high (19-36) ranges. On a European wheel, there are 18 winning numbers for these bets and 19 losing numbers (the 18 numbers of the opposite color/parity/range, plus the single zero). This results in a winning probability of 18/37, or approximately 48.65%. The house edge on these bets is therefore (19 – 18) / 37 = 1/37, which translates to about 2.70%. On an American wheel, there are still 18 winning numbers and 2 red/black/odd/even groups, but now there are 20 losing numbers (the 18 of the opposite group plus the ‘0’ and ’00’). This means the winning probability drops to 18/38, approximately 47.37%, and the house edge climbs to (20 – 18) / 38 = 2/38, or about 5.26%.

Furthermore, certain bets that offer a higher payout naturally become more attractive when the house edge is lower. For example, split bets (betting on two adjacent numbers), street bets (three numbers in a row), corner bets (four numbers), and six-line bets (six numbers) all have calculations that are better for the player on a European wheel. While the payout ratios for these bets remain the same (e.g., split bets pay 17 to 1), the underlying probability of hitting one of those numbers is slightly better on the European wheel due to the absence of the ’00’. This often leads players to favour European roulette for its overall better player-friendly environment.

The “En Prison” and “La Partage” Rules: A European Advantage

Adding another layer to the European roulette’s player advantage are special rules that are sometimes implemented, particularly in French roulette, a variant closely related to European roulette. The “La Partage” rule, meaning “the division” in French, applies to even-money bets (red/black, odd/even, 1-18/19-36) when the ball lands on zero. Under La Partage, if the ball lands on the single zero, half of the player’s even-money bet is returned. This effectively reduces the house edge on these specific bets from 2.70% down to a remarkable 1.35%.

The “En Prison” rule, meaning “in prison,” offers a similar benefit but with a slight variation. Instead of receiving half their stake back immediately, the player’s even-money bet is “imprisoned” for the next spin. If the bet subsequently wins on the next spin, the original stake is returned without profit. If it loses, the stake is forfeited. If the ball lands on zero again, the bet remains imprisoned for a further spin, or until it wins or loses. Like La Partage, En Prison significantly slashes the house edge on even-money bets, making them even more appealing to players seeking to mitigate risk.

These rules, “La Partage” and “En Prison,” are exclusive to certain European and French roulette variations and are not found in American roulette. Their presence offers a substantial statistical advantage to players, further solidifying the European version as the superior choice for those looking for the best possible odds at the roulette table. Casinos offering these rules demonstrate a greater willingness to balance the scales in favor of the player, making the game more engaging and potentially more rewarding for informed participants.

Why the Extra Zero Matters: A Worked Example

Let’s break down a common scenario to illustrate the tangible impact of the extra zero. Imagine you’ve decided to place a $10 bet on red. You’re playing at a table in Las Vegas, so it’s an American roulette wheel with both ‘0’ and ’00’. It’s a straightforward bet: if a red number hits, you win an additional $10 (payout is 1 to 1). If a black number hits, you lose your $10. Now, what happens if the ball lands on zero?

In standard American roulette, landing on either the ‘0’ or the ’00’ is a loss for anyone betting on red or black. So, in this instance, there are 18 red numbers, 18 black numbers, and 2 green pockets. This means there are 20 outcomes where you lose your $10 bet on red, and only 18 outcomes where you win. The probability of winning is 18/38, and the probability of losing is 20/38. The house edge is calculated as the difference between the probability of losing and the probability of winning, divided by the probability of winning (or more straightforwardly, the expected loss per unit wagered). Your expected loss on this $10 bet is $10 multiplied by the house edge. For American roulette, this is $10 * 0.0526 = $0.526. So, on average, you can expect to lose about 53 cents for every $10 bet on red.

Now, let’s rewind the scenario to a European roulette wheel. You place the same $10 bet on red. This wheel has 18 red numbers, 18 black numbers, and only a single green ‘0’. There are still 18 outcomes where you win, but now there are only 19 outcomes where you lose (18 black numbers plus the single ‘0’). The probability of winning is 18/37, and the probability of losing is 19/37. The house edge here is (19 – 18) / 37 = 1/37, which is approximately 2.70%. Your expected loss on this specific $10 bet is now $10 * 0.0270 = $0.27. You can expect to lose about 27 cents for every $10 bet on red. The difference is stark: the extra ’00’ in American roulette effectively doubles your expected losses on this common bet.

Which Roulette Should You Play?

For any player who values their bankroll and is looking for the most statistically favorable gaming experience, the answer is unequivocally European roulette. The lower house edge—2.70% compared to 5.26%—is a significant mathematical advantage that cannot be ignored. This means that over any extended period of play, a player will likely lose less money on a European wheel than on an American wheel, assuming the same betting strategies are employed.

The presence of the single zero in European roulette creates a more balanced game. It offers better odds on even-money bets, makes other wagers less punishing, and can sometimes be combined with player-friendly rules like “La Partage” or “En Prison” that further reduce the house’s advantage. Gamblers prioritizing skill and strategy over pure luck often gravitate towards European roulette because it offers a slightly more forgiving environment in which to play and potentially win.

While American roulette remains popular, particularly in North America, this is often due to its prevalence in land-based casinos and the familiarity players have with it. However, for those seeking to understand the underlying mathematics and optimize their chances, the choice should lean heavily towards European roulette. Embracing the European version is a fundamental step for any discerning roulette player aiming for a more advantageous and, dare we say, more enjoyable gaming experience.