RTP is a game’s long-run average return: 96% RTP means a 4% house edge....

https://tysonsinterestingperspectives.cloudhinter.com/posts/can-i-use-stop-loss-thinking-for-a-casino-session

RTP is a game’s long-run average return: 96% RTP means a 4% house edge. Volatility describes how uneven wins and losses may be. In a short session, results can differ sharply from the average—there’s no guaranteed return.