RTP estimates a game's long-run return: 96% RTP means a 4% house edge....

https://www.quantifiedstrategies.com/rtp-variance-and-expected-value-applying-a-quantitative-framework-to-online-casino-gaming/

RTP estimates a game's long-run return: 96% RTP means a 4% house edge. Volatility describes how uneven results may be. In a short session, you can win or lose far more than the average suggests; RTP is no guarantee of an outcome.