The house edge: why the casino always wins

European roulette has an RTP of 97.3%, and the remaining 2.7% is the house edge — the casino’s guaranteed profit. Different versions and bets give RTPs from 92.1% (the basket bet in American roulette) to 98.65% (even-money bets in French roulette with La Partage and En Prison), but the casino never returns all the money staked as winnings.

How the house edge works

There isn’t a single simple bet in roulette with at least a 50% chance of winning. Even-money bets (paying 1:1) win 48.6% of the time — the player loses slightly more often than they collect, and that produces the 2.7% edge. The same principle applies everywhere: a column or dozen (paying 2:1) wins 32.4% of the time, although “fair” odds with no loss to the player would be 33.3%.¹

Why combination bets don’t save you

Experienced players cover, say, the Voisins and Tiers sectors at once, blanketing most of the wheel for a win on almost every spin. But a combination bet made of several ordinary bets costs more, and its individual components still lose — so the profit comes out modest.

The cost of a rare loss on an expensive combination bet, set against regular but small wins, adds up to the same standard house edge. You can’t override the maths by covering the layout — more in our breakdown of bet types.

Tips for winning

The RTP and house edge only reach their “headline” values over hundreds and thousands of spins, while in short sessions the result is very volatile. If you want to win:

• play short sessions — high volatility can put you up in the short term;
• practise a stop-profit — lock in the result and walk away once your bankroll is up by, say, 30%;
• choose high-RTP variants — the leader here is French roulette with La Partage or En Prison (98.65%).

That said, no instruction guarantees a profit — that’s a mathematical property of the game, not pessimism.