House edge

The house edge is the structural gap, built into the rules of a money game, that makes the player's expected value negative over the long term. It is the organiser's guaranteed margin: on average, the payouts handed out are lower than the stakes collected. This edge does not stem from cheating, but from the way the game is designed.

The intuition is that of a slight permanent offset. The game looks balanced, but the rules tip the scale one notch in favour of the organiser. This offset is invisible over a single session, where the player may well win; it becomes inevitable as sessions accumulate.

It is measured as a percentage of the stakes. If a game pays out on average $95 for $100 staked, the house edge is 5%: it is the share the organiser keeps on average over the long term. From the player's point of view, this amounts to an expected value of minus 5% on each stake. An apparently small edge is enough to guarantee an average loss when you play a lot.

The frequent trap is to believe that a good strategy or a lucky streak can lastingly overturn this edge. This is not the case: since the draws are independent, no method changes the probabilities fixed by the rules. Luck makes results vary in the short term, but the house edge takes over again over time.

On this site, no drawing tool carries a house edge, since there is neither stake nor money at play. Presenting this notion is part of an education in responsible chance: understanding that money games are designed to make the player lose on average helps you view them clear-headedly.