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

https://felixscoolop-eds.lumenforgex.com/posts/what-does-millions-of-spins-mean-for-my-one-hour-session

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