House edge is the profit casinos make on a players original bet amount. The players are at a disadvantage because casinos do not pay the winning wagers according to the ‘true odds’ of the games. There is always a disparity in the true odds and odds that the casinos pay a player. In some skill based casino games, like black jack or Spanish 21, a skillful player can minimize the House Edge (HE) but no one can completely eliminate this factor in casino games.

The calculation of house edge of roulette is a small and easy exercise but for other games it can be very complex and usually requires computer simulation to complete the job. The house edge of casino varies with every game. Slot machines have house edges up to 15% and Keno can have house edges up to 25%. The American roulette have a house edge of 5.26% because of the double zero 00 wheel where as a French roulette has the house edge of 2.70 %. Games like craps, roulette have a fixed house percentage as roll of a dice or spin of a wheel can not change the outcome whereas in blackjack every time a card is dealt, it changes the equation. The advantage can keep shifting depending on cards remaining in the deck and cards that are played. Australian pontoon games offer house edges between 0.3- 0.4 %. Skill based games like Blackjack and Spanish 21, if played well; using the basic strategy can reduce the house edge to 0.5%.