RTP estimates a game’s long-run return: 96% RTP means a 4% house edge....
https://fair-wiki.win/index.php/Does_Session_Timing_Matter_in_Online_Casinos%3F
RTP estimates a game’s long-run return: 96% RTP means a 4% house edge. Volatility affects how often results swing up or down. In a short session, outcomes can differ sharply from the average, so a game’s RTP doesn’t predict what you’ll get back.