What is house edge?
Definition and example from our casino glossary.
Definition
House edge is the average share of each bet the casino expects to keep over the long run, expressed as a percentage of the stake.
The house edge is the casino's built-in mathematical advantage. It comes from paying winning bets at slightly less than their true odds. European roulette has 37 pockets, but a single-number bet pays 35 to 1, giving an edge of 1/37, about 2.70%. American roulette adds a double zero, so 38 pockets at the same payouts give 5.26%. For slots, the house edge is 100% minus the RTP. Blackjack played with correct basic strategy under common rules carries roughly 0.2% to 0.6%, while the baccarat banker bet is about 1.06%. The edge applies to every bet you place, not to your deposit, so turnover multiplies it: re-staking the same money many times increases the expected loss. No betting system can remove a negative edge, which is why the house edge is the most useful single number for comparing games.