Usually, when people say that it’s better to play European roulette than the American version of the game, they’re referring primarily to the fact that European roulette wheels feature just one zero, while American roulette wheels add the double zero – nearly doubling the house edge. However, if you play in some swankier casinos, you’ll find a few single-zero wheels around, even in casinos that offer only “American” roulette.
Yet these games still aren’t as good as the European version of the game. This is because European roulette games – like the ones commonly found in Australia’s land-based casinos – also feature an additional rule known as “en prison.” This rule makes the house edge even lower on even money bets, making them just about as good a bet as most table games, in the same range as favourites like making the pass line bet in craps or the banker bet in baccarat.
The en prison rule only affects even money bets, and since it’s a good bet for the player, it makes sense to focus on these bets when playing European roulette. If a player makes an even money bet and the ball lands on zero, one of a number of things may happen that essentially result in the player getting about half their money back in the long run.
In fact, in some casinos, that’s exactly what happens. In this version of the rule – known as “la partage” – the player is simply given back half of their bet, meaning they lose only half as much as on any other loss. This is similar to the “surrender” rule in blackjack, in that it protects the player from a total loss at the cost of half their bet.
Many casinos around the world use an alternate version of the en prison rule that allows players the chance to rescue all of their money. Instead of simply giving the player half their bet back, the money will become “imprisoned” and held over for the next bet. Should the player’s bet win on the next spin, they’ll rescue the bet, though they won’t be awarded any winnings. If the bet loses, they’ll finally lose their bet for good.
Where it gets a little confusing is what happens when the ball lands on zero for a second time. In many casinos (especially in France), this result is simply ignored; the bet just stays imprisoned, and it only becomes rescued or lost based on the next result that isn’t a zero. Other casinos will treat a zero as a loss just like any other.
Still other casinos have a policy of double or triple imprisonment. In these cases, you’ll still have a shot at rescuing your bet on a second consecutive zero, but your job gets a little tougher. First, you’ll need to win one spin to get your bet out of “double imprisonment” and back to the standard en prison position. Only then can you have a shot at rescuing the money for good. Any loss during this process causes you to lose the money. Some casinos will take this a step further, offering triple imprisonment or more upon more consecutive zeroes – though, of course, hitting that many zeroes in a row is an extremely rare event.
In many casinos in Australia (and on many online casino sites), you won’t be given an option as to how to treat your en prison bet; either they’ll use la partage and give you half your money back, or you’ll be forced to sweat out the imprisonment. Some casinos do give you a choice, though, and in most cases, it’s definitely better just to take your money back. Since another zero will hurt you (either by losing your bet or setting you into a double imprisonment), you’re a little worse than 50/50 to save your bet; taking half the money instead will save you a little more in the long run. However, if the French rule where zeroes have no impact on the results is being used, you’ll get the same results either way in the long run, so opting for either rule is fine.