Playing England, my king had one child, a girl, in his early thirties, then decided to become a celibate (by my choice.)

He also has syphilis, and his wife is depressed. So there are a lot of negative fertility traits going, celibacy itself is -1000% fertility.



So I'd basically accepted that my daughter would grow to become the new monarch, since I had the agnatic-cognatic laws already. (+primogeniture)

I was tutoring her and by the time she was 12 she already had very good traits: Strong, Ambitious, Brave Temperate.



Then lo and behold suddenly my wife was pregnant again. She ended up having a son who became my new heir and since my daughter was ambitious her relations with me went from +50 to -50.

Well I just ended up assassinating my son anyways a few days after he was born. And now my daughter is 16 and on her way to becoming the new monarch after I die.



So I thought I would see what anyone thought about how the fertility percentages affect the game. Since me and my wife had more than -1000% fertility plus syphilis and one or two others, and she still got pregnant.

Is this an extremely rare occurance? I thought having just -40% fertility made it difficult to have children.



I should also add that when my king was married at about age 17, until his 30s, he didn't have any children with his wife, until that first daughter. And that was before he became a celibate.