WHAT ARE "EN PRISON" AND "LA PARTAGE" RULES FOR ONLINE ROULETTE?
As you know French roulette wheels feature just one zero, while American roulette wheels add the double zero. The house edge on American Roulette is 5.26% while on French Roulette it is 2.7%.
"En Prison" and "La Partage" are a fantastic addition to French Roulette as they reduce the house edge on outside even money bets by half, from 2.7% to 1.35%.
These rulese come into effect when the ball lands on the zero and you have placed an even money bet such as red-black or even-odd.
"LA PARTAGE" RULE
When an online casino offer La Partage and the ball lands on zero, all even-money bets are immediately divided by two so that half of the original wager can be returned to the player.
You stake £100 on red/black, which pays even money, and a 0 is spun. If La Partage is activated, you at least get £50 back on your loss.
"EN PRISON" RULE
When an online casino offer En Prison and the outcome of a spin is 0, the casino will leave all even-money bets for another roulette spin. If the bet goes on to win, your original stake is returned. If it loses, well, you lose it. In case the outcome of the second spin is again zero, then the whole bet is lost. So, actually, the player has already lost half their bet, and must now win the next spin to get back their original bet.
You stake £100 on odd/even, and the ball lands on zero. Instead of losing everything, your bet remains until the next spin to determine if it is a winner or loser.
Some casinos offer double and triple imprisonment. Anyway, two or three consecutive zeroes is an extremely rare event.
Obviously there are some roulette systems that involve red/black, odds/even or first 18/second 18 (as well as Martingale system players) that benefit from these two rules.