RTP is a game’s long-run expected return; the house edge is the share it keeps....

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

RTP is a game’s long-run expected return; the house edge is the share it keeps. A 96% RTP means a 4% house edge, not a promise for tonight. Volatility shapes how wins and losses arrive. In a short session, results can swing sharply and differ widely.