House Edge

House edge is RTP inverted: European roulette’s 2.7%, blackjack’s ~0.5% under good rules and correct play, slots typically 3–6%.

Why the small numbers dominate

Edge compounds with turnover: a 2.7% edge on a player recycling winnings produces far more than 2.7% of their deposits — which is how modest edges fund an industry. The same math powers wagering requirements (expected cost ≈ edge × required turnover) and explains bonus economics better than any marketing copy. The sportsbook equivalent is the overround baked into odds.