I'm often left scratching my head at the choices my courtiers or neighbors make. For example, sometimes I catch wind of a plot to kill somebody where there is no obvious relationship between the plotter and the victim. Or I get people who resign from my council without having any obvious negative reasons (ie. they still like me, are the most qualified, not old, maybe not married or has no kids, not stressed out, etc.).
Is there a mod or set of console commands that would allow me to figure out what makes these people tick? Something must make them want to kill other courtiers or quit my council just to be reappointed 10 seconds later. It'd be nice to get some insight into what motivates their seemingly random actions!
Best Answer
There is a certain hidden stat "rationality" which is influenced by various traits. A character with a low rationality is prone to making random decisions, like killing people without a reason or declaring a war they can not win.
Traits which result in a very low rationality are:
There are also traits which improve rationality:
So when you notice a character making strange decisions, check if they have one or more traits which lower their rationality. When you don't find any, chances are that they (or their offspring) do in fact benefit from the action in a way which you don't realize.
Source for these numbers is the CKII wiki whose authors apparently extracted them from the data files of the game.
By the way, when you notice that landless people get removed from your council with no apparent reason, they might have somehow gained a landed title. This well-known glitch is described in this question.