RTP stands for 'Return to Player' and it is a percentage that indicates the amount of all the wagered money a slot machine will pay back to players over time. For example, if a slot has an RTP of 96%, theoretically, for every $100 bet, the machine will pay out $96 over a long period of play. The RTP is crucial as it helps players understand their potential for winning. A higher RTP means a better chance of getting a return on your bets in the long run.