Date: July 14, 2026 | Reading time: 11 minutes | Author: Giulia Moretti
Every casino game has a number describing how much the house keeps over the long run. It is neither an opinion nor a commercial policy: it follows from the rules and can be calculated. Knowing it is the difference between choosing a game and being subjected to one.
House edge and RTP: two ways of saying the same thing
The house edge is the share of the stake the house keeps on average. RTP (return to player) is its complement: an RTP of 96% corresponds to an edge of 4%. Both hold over the long run and across many rounds: in a single evening variance dominates, which is why you win or lose more than the number suggests.
Roulette: 2.70% against 5.26%
In European roulette, with a single zero, the edge is 2.70% on almost every bet. In the American version, with zero and double zero, it rises to 5.26%: nearly double, for a game that looks identical. It is the most important choice you make at this table, and you make it before betting.
The French version adds the La Partage or En Prison rules, which return half the stake (or freeze it) on even-money bets when zero comes up: the edge on those bets falls to 1.35%. It is the best number roulette offers.
Inside odds do not change the picture: straight up 35:1, split 17:1, street 11:1, corner 8:1, six line 5:1, dozen and column 2:1, even money 1:1. All produce the same edge, with different variance.
Blackjack: under 1%, but only with basic strategy
Blackjack is the only common table game in which the player's decisions change the edge. With basic strategy — the table giving the optimal move for every combination of your hand and the dealer's up card — the edge typically falls below 1%. Playing on instinct can easily push it past 2%.
Watch two details that make it worse: blackjack paying 6:5 instead of 3:2 adds roughly 1.4% of edge, and insurance is almost always an unfavourable bet. Both are printed on the table, before you sit down.
How to read these numbers: an edge of 2.70% means that for every 100 euros wagered in total (not deposited), the expected loss is 2.70 euros. If you replay your winnings, the same note is staked several times and the edge applies each time.
Poker remains the exception: there the opponent is not the house but the other players, and the operator earns from the rake. The table rules are in Poker at the casino: table rules and beginner mistakes.
Slots and other games
Slots declare an RTP normally between 92% and 97%; the figure appears in the game information. Baccarat runs about 1.06% on banker and 1.24% on player, while the tie bet is far worse. Progressive jackpot games take a slice of every stake to feed the pool: the effective RTP depends on how large the jackpot is at that moment.
The mistakes that worsen the numbers
Choosing American roulette when the European wheel is available. Accepting 6:5 blackjack tables. Betting the tie at baccarat. Using progression systems such as doubling after every loss: they do not change the edge, they only increase the money exposed and the chance of hitting the table limit. The rituals that accompany them are described in Superstitions at the table: why rituals do not change the odds, and the way rooms are built to keep you playing longer in How gaming floors and slot machines are designed.
The number that matters most stays the one you choose yourself: how much you are prepared to lose in an evening. How to fix it is in Bankroll: how to manage your budget at the casino.
Play responsibly, 18+ only.
