RTP estimates the share of stakes a game returns over a very large number of...

https://www.wall-bookmarkings.win/rtp-is-a-long-run-average-not-a-session-forecast-96-rtp-means-a-4-house

RTP estimates the share of stakes a game returns over a very large number of plays; it is not a promise about one session. A 96% RTP means a 4% house edge on average over time