RTP is a long-run average; house edge is the casino’s expected share: 96% RTP =...

https://www.inter-bookmarks.win/rtp-estimates-the-share-of-stakes-a-game-returns-over-a-very-large-number-of

RTP is a long-run average; house edge is the casino’s expected share: 96% RTP = 4% house edge. Volatility affects how wins and losses arrive. In a short session, results can vary sharply, so RTP isn’t a promise of what you’ll get.