Casinos make money through the house edge, which is the long-term advantage that the casino has in any game. Some form of house edge is present in all games offered at casino sites, though all games have a different house edge figure. The house edge serves to keep the casinos in business. For example, in American roulette there is a 5.26% chance that the ball will land in the 0 or the 00 slot. If it lands in either, the vast majority of player bets are lost, including all of the popular outside ones. The house therefore wins all the money. In the long term, for every $100 bet in the roulette game, the casino will win around $5.26 of it. This is the house edge.