In two separate games, twice I received the event that allows you to become Cathar, and I never received events towards other heresies.
Since I like very much to play as Cathar, I'd like to know how to maximise the chances of getting this event.
As far as I know you just have to be Catholic, and put your Chaplain in your home province to research cultural tech… so, besides having a Chaplain with a high learning, it's just luck?
Was it just happenstance that I twice got to become Cathar and not another heresy, or is this culture dependant? First time I was Irish, second time Breton.
This, assuming there are no other Cathars to be found, of course.
The only DLC I have is Sons of Abraham, and this must work on Ironman mode.
Best Answer
If you really want to become Cathar, I think there are more effective ways of doing this. I can think of two:
Also, note that heresy in general spreads faster if moral authority of your religion is low. You can help it along by appointing an anti-pope.
If you really want to stick with the court chaplain research, you can see the chances of his "failure" in the tooltip - failure means he becomes a heretic. I think the game just picks a heresy at random though, so I think this could take a long time.