I think house edge can be found in almost every casino game, including slot machines, blackjack, roulette, baccarat, craps, and many others. It is typically expressed as a percentage of each bet that is expected to be retained by the casino over time. For example, a typical slot machine might have a house edge of around 5%, meaning that over time, the casino can expect to retain about 5% of every bet that is placed on that machine.