The biggest problem with slots is you can never know what the house percentage is. On the other “big three” we can be precise. The house percentage is 5.26% at roulette and 1.414% on the come bet at craps. The house edge at blackjack depends on the rules and the skill of the player. The “basic strategy” player is usually looking at a house edge of less than 1%, and closer to ½% with good rules.