The En Prison rule is offered in European and French roulette games
. If you place a bet on an even money spot and the ball lands in zero, then you have the option to put the bet "in prison". If your next bet wins, then you win back the imprisoned bet.
Winning scenario: Player A places a £10 bet on red, but the ball falls in the zero pocket. The croupier will then offer the option to take half the stake back or to imprison the bet. Player A chooses to imprison. The next spin is on red and Player A wins back their stake.
Losing Scenario: Player B places a £10 bet on black, but the ball falls in the zero pocket. The croupier will then offer the option to take half the stake back or to imprison the bet. Player B chooses to imprison. The next spin is on red and Player B forfeits their stake.
En Prison Rule Odds
This rule is offered alongside the La Partage rule
, so the two work in tandem. In essence, you can either choose to lose just half your stake - or potentially win it all back.
Roulette games with En Prison are more favourable for the player than the house. Here is a comparison between the different roulette wheels and their house edges:
- American Roulette: 5.26% house edge
- European Roulette: 2.70% house edge
- European Roulette with En Prison/La Partage rule: 1.35%
There are two scenarios if an En Prison bet falls into the zero pocket on successive spins.
- The bet loses and the player does not receive winnings or their original stake
- The bet is imprisoned again - to release the bet, you will need to win two consecutive spins
In the unlikely event that a bet falls in the zero for a third time, the bet will be tripled imprisoned.
En Prison Roulette Online
None of the major casinos or software providers offers a game with the En Prison rule. You will find online casinos that do offer La Partage Roulette.
There are two theories as to why there is a lack of games that offer this rule:
- It slows down the game too much
- It offers players a way to get their full stake back
History of En Prison Roulette
It is unknown who created the En Prison rule. But it is established the original inventor of the mechanism for roulette, Blaise Pascal, did not create this rule.
We know the rule originated in France due to its name. Theories suggest that La Partage and En Prison started to surface in the 18th century. Further evidence points to Parisian casinos offering this rule to get more gamblers in the door.
With better odds and higher returns, both rules, in theory, would be more appealing to casino goers.
What is the best En Prison strategy?
The strategy is identical to La Partage - only play on even money bets. This includes red/black, odds/evens and highs/lows.