RTP, Volatility and House Edge: What the Numbers Mean

Return to player (RTP) is the percentage of total stakes a game returns to players over a very large number of rounds. A slot with 96 percent RTP has a 4 percent house edge, meaning the theoretical long-run cost is 4 units for every 100 staked.

Three things people commonly get wrong.

RTP is not a session guarantee. It is calculated over millions of spins. Any individual session can land far above or far below it, in either direction.

RTP can vary by version. Some slots ship in multiple RTP configurations and the operator chooses which to deploy. Reputable casinos display the active RTP in the game information panel — check it there rather than assuming the figure quoted elsewhere.

Volatility is separate from RTP. A low-volatility slot pays small amounts often; a high-volatility slot pays rarely but larger. Two games with identical RTP can feel completely different, and high volatility means longer losing stretches are normal rather than a sign something is wrong.

Table games have their own edges. European roulette carries a 2.7 percent house edge from the single zero; American roulette roughly doubles it with the double zero. Blackjack's edge depends on the rules and on the accuracy of the player's decisions.

None of these numbers make gambling profitable. A negative expected value is a design feature of every casino game.