Roulette "La Partage" and "En Prison"

Roulette wheel
By Ralf Roletschek - Own work, CC BY-SA 3.0, Link

Roulette is one of the most popular casino games and is played worldwide, but the rules and options differ from country to country and even casino to casino. Not all wheels and layouts are the same, and French casinos often offer "La Partage" and "En Prison," which make for better player odds. Make sure you know the options before you risk your money!

In most European casinos, a wheel with a single zero (green) is offered.

As such, the odds against any single number coming up on the next spin are 1 in 37 (36-1), since the pockets for the ball to land in run from 1 to 36 and also include 0. With this type of wheel and no other options, the house retains a 2.7 percent advantage.

When roulette wheels were introduced to the US in New Orleans and later the mining towns of Nevada and California, most gamblers were unfamiliar with the French version of the game and were little concerned with the added 00. In fact, some wheels produced had a zero, double zero, and an eagle, which was also a "house" slot - with only 28 other numbers. The house odds on that game were a hefty 9.7 percent.

Today, most North American casinos still use a wheel with both a single zero and a double zero. A few Las Vegas casinos do offer single zero, but the wheels are invariably found only in the high-limit rooms of places like Bellagio and Wynn.

French Innovation

Roulette was so popular in the 1800's that Frenchman Francois Blanc (while working in the German spa town of Homburg, introduced the single-zero wheel to draw more business to his casino. When gaming was outlawed in the 1860's, Blanc moved to Monte Carlo and helped turn the small municipality into a gambling mecca.

In addition to the lower house edge of the single-zero wheel, many French roulette games also offer one of two additional options: "La Partage," and "En Prison."

The French roulette layout offers the standard set of three even-money bets: red/black (often termed Rouge/Noir); even/odd (often termed Pair/Impair); 1-18/19-36 (often termed Manque/Passe). It is these particular bets that are affected by the La Partage and En Prison rules.

La Partage

La Partage (the divide)is an option offered automatically on many French roulette tables. It is enacted when the ball lands on zero, and all even-money bets are immediately divided by two so that half of the original wager can be returned to the player. This is done automatically and reduces the house edge of all even-money bets to just 1.35 percent. Obviously, there are some betting systems that involve red/black as well as first 18/second 18 that benefit from this rule.

En Prison

The En Prison rule is a bit more complicated, and some players feel that the La Partage rule is more beneficial, but the house edge is the same at most casinos. This is because when a zero is spun, the dealer places a marker over each even-money bet, placing the wager in prison for the next spin.

This means the player is again betting on the same wager, however, if it wins, only the original bet is returned. It does not win an additional bet. This means that in reality, the player has already lost half their bet, and must now win the next spin to get back their original bet (an original $100 bet on black when zero spins is placed in prison for the next spin. If black comes up, $100 is returned. If it does not, the player loses the whole $100.

At very few casinos, the En Prison rule is further complicated by the "second spin zero" rule. At these locations, if zero is followed by a second zero, the bet may be lost, won, or left for additional spins. Obviously, it would be best if it became a winner, but this is exceedingly rare. It is much more likely the bet will lose on the second spin if zero (green) is spun again.

En Prison and La Partage do not affect the inside bets or column and section bets, which lose when zero is spun, negating any advantage seen for most betting systems. However, a crafty Martingale system player will gain a distinct advantage with La Partage.

European and French roulette are also associated with "announced bets," much like call-bets at US craps tables. Announced bets mostly involve sections of the wheel and substantial wagers that are quickly acknowledged and accepted by the croupiers. Maximum wins on these wheels are often much higher than American counterparts. A "seventeen to the max" bet in the UK involves 40 separate bets ($40,000 total on a $1,000 table) and would create a $392,000 payout if number 17 is spun.

In a US casino, "announced bets" are not a standard form of wager and a player must place the chips themselves on most wagers. In addition, tables in most locations have a set maximum payout. This is as little as $25 straight up and $1,000 max per spin in small casinos, to $5,000 or $10,000 at most larger casinos.