The roulette ‘house edge’ is simply the advantage the casino (the house) has over you, the player. Because there is an extra 0 (or even an extra 00 in American roulette) in addition to the 36 standard numbers, you are at a slight disadvantage when betting on red/black or even/even. That house edge also applies to bets with smaller odds of higher winnings. As we showed earlier, in European roulette the house edge is 2.7%, while in American roulette it is 5.26% due to the extra 00 box.