The la partage, loosely translated as sharing rule, is a nice benefit of playing French roulette. Typically applicable to even money bets, what it does is give you back half your wager if the ball lands in the zero pocket.
The en prison rule is similar, except while the house still takes half your stake, the other half remains in place, ie. imprisoned, for another spin of the wheel – so you’re basically getting a second chance on your bet.