Roulette En Prison: A Deeper Look at This Unique Rule

By Alex Bennett · Updated 28 August 2026

The Roulette en prison rule offers a unique twist for players betting on even-money outcomes in European or French roulette, significantly altering the risk-reward dynamic. When a zero hits, your outside bets aren’t immediately lost. Instead, they are “imprisoned,” meaning they remain on the table for the next spin. If your bet wins on that subsequent spin, you get your original stake back, but no winnings. If it loses, you lose your entire stake. This rule effectively halves the house edge on these bets, from 2.70% to 1.35%, making it a highly attractive option for cautious players in certain scenarios.

Understanding when and why the roulette en prison rule comes into play is crucial for any serious roulette enthusiast looking to optimize their gameplay. It’s not a universal offering and typically appears on specific tables or within certain jurisdictions. The core concept revolves around mitigating the impact of the zero, a number that otherwise spells doom for all outside bets. By giving players a second chance, albeit without the potential for profit on that specific spin, the rule introduces a strategic element that distinguishes it from standard roulette play.

This article will delve into the intricacies of the roulette en prison rule, exploring its origins, how it’s implemented, and the mathematical advantages it confers. We will break down its impact on your wagers and provide a practical example to illustrate its function in real-time gameplay. By the end, you’ll have a comprehensive understanding of this fascinating roulette variation and how it can potentially benefit your bankroll.

What is the Roulette En Prison Rule and How Does it Work?

At its heart, the roulette en prison rule is a modification applied to even-money bets – those covering Red/Black, Odd/Even, and High/Low numbers. These bets traditionally pay 1:1. The defining characteristic of roulette, especially European and French variations, is the presence of a single zero (0). When the ball lands on zero, all even-money bets placed on that spin are typically lost immediately. However, the “en prison” rule intervenes.

Instead of forfeiting your stake, your bet is placed “in prison.” This means it remains on the betting area for the next spin of the wheel. You are not required to place an additional bet; it’s a single, free re-spin for that particular wager. The outcome of this re-spin determines the fate of your imprisoned bet. If the number that corresponds to your bet (e.g., red, if you bet on red) hits on the next spin, you receive your original stake back. Crucially, you do not win any profit for that spin. Think of it as a ‘push’ or a ‘standoff’ on that specific outcome.

Conversely, if the ball lands on zero again, or any number that doesn’t match your bet, your imprisoned stake is lost to the house. The probability of the ball landing on zero in European roulette is 1 in 37 (approximately 2.70%). With the roulette en prison rule, this single possibility is now split across two spins. If the initial spin is zero, your probability of losing your stake is reduced because you get a second chance. This significantly impacts the house edge on these particular bets.

The Mathematical Advantage: Reduced House Edge

The most compelling reason to seek out tables offering the roulette en prison rule lies in its direct impact on the house edge. In standard European roulette, where the single zero is the only house number, the house edge on outside bets and inside bets alike stands at 2.70%. This figure represents the average percentage of each bet that the casino expects to keep over the long term.

When the roulette en prison rule is active for even-money bets, the house edge is effectively halved for those specific wagers. Let’s break this down. For a bet to be ‘en prison,’ the first spin must land on zero. The probability of this happening is 1/37. On the subsequent spin, if your bet wins, you get your stake back (a 1:1 payout scenario effectively reduced to 0:1 profit). If it loses, you lose your stake. Consider a €10 bet. If zero hits, your €10 is imprisoned. On the next spin, if your bet wins, you get €10 back. If it loses (or zero hits again), you lose your €10. This effectively means that for every 37 spins where zero could hit, you are only truly risking your stake on 36 of them for the purpose of profit, with the 37th spin offering a chance to reclaim the stake. The net effect is a house edge of approximately 1.35% on these specific bets, a substantial improvement for the player.

This reduction makes the roulette en prison rule one of the most player-favorable conditions in casino gaming. While it doesn’t apply to all bets (typically not to inside bets like single numbers or splits), for those who prefer simpler, higher-probability wagers, it’s a significant advantage. Casinos offering this rule often do so to attract a more discerning player base or as a feature of French roulette tables, which historically had more player-centric rules.

When Does Roulette En Prison Apply?

The application of the roulette en prison rule is primarily associated with French roulette, though some casinos may adopt it for their European roulette tables as a special feature. It’s essential to verify the specific rules of any table you approach. Look for signage or ask the croupier clearly before placing any bets. The rule is almost exclusively applied to even-money bets: Red or Black, Odd or Even, and High (19-36) or Low (1-18).

The trigger for the rule is, as mentioned, the ball landing on the single zero (0). It is not triggered by the double zero (00) found in American roulette. Therefore, if you are playing American roulette, you will not encounter the roulette en prison rule; the presence of the double zero already inflates the house edge to 5.26%, making player-favorable rules like this less likely to be offered.

Furthermore, the “en prison” implementation can sometimes vary. In some casinos, the rule might be “la partage,” which is similar but slightly different. With “la partage,” if zero hits, half of your even-money bet is returned to you immediately, and the other half is lost. The roulette en prison rule offers a second chance with the full stake imprisoned. Always clarify which rule is in effect. The core principle remains the same: a reduced house edge on even-money bets when zero appears.

Worked Example: En Prison in Action

Let’s illustrate the roulette en prison rule with a practical example. Imagine you are playing at a French roulette table that offers this rule. You place a €20 bet on Red.

Spin 1: The wheel spins, and the ball lands on 15, which is a black number. Your bet on Red loses. However, since the table has the roulette en prison rule, and the outcome was not zero, your bet is simply lost as usual. If you had placed your €20 bet on Red and the ball landed on 0, the situation would be different.

Spin 1 (Revised Scenario): You place a €20 bet on Red. The croupier spins the wheel, and the ball lands on 0. Because the table operates under the roulette en prison rule, your €20 bet on Red is not lost. Instead, the croupier will place a marker on your bet, indicating it is “imprisoned” for the next spin.

Spin 2: The croupier spins the wheel again. This is a free re-spin for your imprisoned bet. The ball lands on 22, which is a red number. Your original bet on Red now wins. According to the roulette en prison rule, you get your original €20 stake back. You do not receive any winnings because the profit element of the 1:1 payout is voided by the ‘en prison’ condition. Effectively, you have broken even on this sequence of two spins after the zero hit. If, on Spin 2, the ball had landed on 7 (black) or even 0 again, your imprisoned €20 bet would have been lost.

This example clearly shows how the roulette en prison rule provides a safety net against the zero, allowing you to reclaim your stake on your next valid spin, albeit without profit potential for that specific turn.

Pros and Cons of Playing with En Prison

Playing at tables featuring the roulette en prison rule offers distinct advantages and some considerations to keep in mind. The primary benefit, as extensively discussed, is the significantly reduced house edge on even-money bets. With the standard European roulette house edge at 2.70%, the en prison rule (or the similar ‘la partage’) effectively halves this to about 1.35% for these wagers. This is among the best odds available to players in a casino setting for any table game, making it a favorite for those who prefer low-risk, high-frequency betting strategies.

The psychological advantage is also notable. Knowing that a zero doesn’t automatically wipe out your bet can lead to a more relaxed playing experience. It removes some of the sting associated with the most dreaded outcome for outside bettors. This can encourage players to stay at the table longer, enjoying the game without the constant dread of a single zero. The roulette en prison rule encourages a more strategic approach, where players might be more inclined to place even-money bets knowing the inherent protection offered.

However, there are cons. The most obvious is that the roulette en prison rule only applies to specific bets: Red/Black, Odd/Even, High/Low. Inside bets, such as betting on a single number, splits, or corners, do not benefit from this rule. If you are an inside bettor seeking high payouts, this rule offers no direct advantage. Another consideration is availability; you may not find tables offering this rule in every casino or even at every roulette table within a casino. You’ll need to seek out French roulette tables or those explicitly advertising the “en prison” or “la partage” rule to leverage this player-friendly condition.

FAQ About the Roulette En Prison Rule

When does the roulette en prison rule offer the best value for players?

The roulette en prison rule offers the best value when you are consistently betting on even-money outcomes like Red/Black, Odd/Even, or High/Low. This rule effectively reduces the house edge on these specific bets from 2.70% to approximately 1.35%, providing a more favorable playing environment compared to standard European or French roulette tables without this stipulation.

Can I win money with the roulette en prison rule on the subsequent spin?

No, you cannot win additional money with the roulette en prison rule on the spin immediately following the zero. If your imprisoned bet wins on that next spin, you only receive your original stake back. The profit portion of the payout is forgone as compensation for the protection the rule provides against the zero hitting.

Does the roulette en prison rule apply to inside bets?

No, the roulette en prison rule exclusively applies to even-money outside bets. These include bets on Red/Black, Odd/Even, and High/Low. Inside bets, such as betting on single numbers, splits, or corners, are not affected by this rule and will be lost immediately if the ball lands on zero.