What Is RTP - The Foundation of Every Casino Game

RTP is Return to Player, and it denotes the percentage of all money which has been gambled that a casino game will pay out in the long run. This is a theoretical payout and is calculated on long-term outcomes, so it is the overall payout of the game, not the result of one specific session. For example, if a slot machine offers an RTP of 96%, it means that, on average, of every $100 bet, $96 will be returned to the players as winnings, and the $4 difference is the house gain.
The idea is that RTP is not a guarantee for a single session or player. It's an average of millions of spins or rounds of play, so it's a useful indicator of the long-term expected return on a game. You might win the jackpot on one spin, but RTP is more indicative of what will happen in the long run.