Crusader Kings offers both a chance to roleplay as a medieval lord, and simulate the personality traits and petty grievances of a network of interdependent rulers. Sometimes, those features are at odds with each other – no matter how mean or stupid your character is, you could play them however you want. That’ll still be the case in Crusader Kings 3, but your rulers will have a tough time reconciling if they’re forced to act against their personalities.
Taking actions that go against your ruler’s personality will cause side effects – in the most extreme cases your ruler could lose their mind, according to a breakdown in PC Gamer magazine issue #338. Your ruler will have to relieve stress somehow, and that might include unhealthy obsessions with alcohol, sex, or torture.
Or, for an athletic ruler, it might just mean some extra workouts. Game director Henrik Fåhraeus says “we want it to mean something, but not to the level of being the only thing you think about. So it’s an interesting mechanic, but it’s not supposed to overpower your gameplay.”
Original source: https://www.pcgamesn.com/crusader-kings-3/roleplay