iGaming Glossary / En Prison
What is En Prison?
A French roulette rule that can return an even-money bet after a zero spin, lowering the house edge.
En prison is a French roulette rule that softens the blow when the ball lands on zero. Instead of losing an even-money bet straight away, such as red, black, odd or even, the stake is held or imprisoned for the next spin. If that next spin wins, you get your original stake back with no profit.
Why it matters: this rule roughly halves the house edge on even-money bets, making French roulette one of the better-value versions of the game. It is closely related to the la partage rule, which returns half the stake immediately instead.
The catch is that en prison only applies to even-money bets, not to numbers or other inside wagers, and not every table offers it. Look for it before you sit down. The roulette guide explains the variants.
Related terms
Browse every definition in the full iGaming glossary, or see our casino reviews and game providers. 18+.