House edge
What is House edge?
The house edge is the share of all wagered money that the operator retains on average over the long run. In slot machines it is derived directly from RTP: house edge = 100% minus RTP. A game with a 96% RTP therefore carries a 4% house edge. Like RTP, it is a long-term theoretical average calculated over millions of spins, not a fixed cut taken from each individual bet.
Relationship with RTP
RTP and house edge are two expressions of the same figure. A 95% RTP means a 5% house edge; a 98% RTP means a 2% house edge. Online slot machines typically operate with house edges in a range from around 2% to 10%, though values vary widely by game and operator configuration.
Short-term behavior
Over a short session, actual results can deviate substantially from the theoretical house edge in either direction. A player may end well ahead of expectations or well below them. The house edge only approximates real behavior reliably over a very large number of spins.
Comparing games
The house edge is a useful metric for comparing games or game types. A slot with a 3% house edge is mathematically more favorable than one at 7%, all else equal. That said, volatility and payout structure also shape the playing experience in ways the house edge figure alone does not capture.