RTP is a game’s long-run payback rate: 96% RTP means a 4% house edge on...

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

RTP is a game’s long-run payback rate: 96% RTP means a 4% house edge on average. Volatility describes how often and how much wins vary. In a short session, results can swing sharply either way; the long-run average won’t predict your outcome.