Betrayal is a game played in two phases. On the first part you're just going around the house exploring, getting items and events. Then suddenly everything changes.
Someone or something is revealed as the traitor and all rules drastically change. Depending on different factors, a scenario will be chosen which will explain the rules to everyone. Lots of them are betrayer vs rest, but not all.
The game is fun to play with at least 3 players and you can never know what to expect from the 50 scenarios that come with the base game. It's not a competitive game which you want to play to win, rather a fun, wild experience, given that most games are inbalanced.
Despite this I definitely recommend this game to people looking for a good "storytelling" game, in which you can't really be the master of you destiny, but who rather want to have a laugh while being beaten by a little girl turned into an OP tentacle monster