The 'La Partage' and 'En Prison' rules apply to outside “even money” bets (bets that offer a 1-1 payout like odd or even, black or red, and low or high) they also apply when the ball lands in the 0 slot. Some French tables will employ rules that generally help out the players.However, there are some variants that change how the favor lies: X Research source There are theories as to how you can improve your odds, but they don't work. The house’s advantage comes from its additional number 0 (which offers the house an additional 2.7% chance of winning, compared to the players).
Know that at every roulette table (and at every game in the casino itself), the “house” (the casino) always has an edge. Recognize the “house edge” and how it affects your odds.