RTP is the long-run share a game is designed to return; the house edge is the...

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

RTP is the long-run share a game is designed to return; the house edge is the remainder. A 96% RTP means a 4% house edge, not a guaranteed loss of 4% per session. Volatility shapes how wins and losses arrive, and short-run results can vary sharply.