The house edge is the mathematical percentage of each bet the game is designed to keep for the house over time — 100% minus RTP, and the reason casino revenue trends positive across enough rounds.

What the house edge is

The house edge is the built-in mathematical advantage every casino game gives the house, expressed as a percentage of each bet. It is simply 100% − RTP: a game with 96% RTP has a 4% house edge, meaning that over a very large number of rounds the house expects to keep ৳4 of every ৳100 wagered.

The edge is not a per-round guarantee. On any single round the player can win multiples of their stake. The edge only expresses itself as a trend, emerging from the law of large numbers as volume accumulates.

Typical house edges by game type

European roulette: 2.7% (single zero). American roulette: 5.26% (double zero).
Blackjack with basic strategy: 0.5–2% depending on rules — the lowest edge in a standard lobby, which is why rule quality matters.
Slots: 4–10% (RTP 90–96%), varying by title and RTP configuration.
Crash games: edge lives in the bust curve; typical designs keep 1–4%.
Sportsbook: margin per market rather than an edge per bet — commonly 2–8% depending on the market's liquidity.

House edge → GGR → what you actually earn

Worked example: ৳10,000,000 of monthly turnover across games averaging a 5% edge → expected GGR ≈ ৳500,000. With a GGR-based platform fee of 10%, the fee is ৳50,000 and roughly ৳450,000 remains before other costs. This is why a lobby's average edge and the platform's GGR rate are the two most commercially important numbers in an operator's economics.

Each round's edge is applied to the stake: expected revenue per round ≈ stake × house edge.
Realised GGR is the sum of (bet − win) across all rounds in a period — it wobbles around the expected figure with variance.
Your net revenue is GGR minus the provider/aggregator fee (a percentage of positive GGR), payment costs, bonuses and taxes.

Practical operator takeaways

A lower edge (higher RTP) is not automatically better: high-RTP low-volatility games retain differently than high-volatility jackpots. Judge by realised GGR per player, not by edge alone.
Watch the realised RTP of your own players from round-level data — it converges to theory as volume grows, and persistent deviation is worth investigating.
Your platform fee is charged on positive GGR, so the edge net of that fee — edge minus fee-rate — is your true per-bet margin.