Crusader Kings II - Mod General

[Monk]

I tried experimenting with various conditions listed on the CKIIwiki, but they either cause my game to crash or dont have the wanted effect. Any ideas on how to do this? Apparently the condition "is_child_of" is the solution I am looking for but I am not sure how to use it...

I've never messed with traits but a couple of ideas come to mind after doing a few quick code experiments. You want to define that the trait is only giftable at birth which may be why people are popping up in other parts of the world with the trait.

The game randomly generates characters to inhabits courts whenever conquests happen and everyone previously was thrown out. Like in the case of holy wars. All of those characters get randomly assigned traits unless they get stopped by flags. Likewise, without a congenital flag, it's possible the game thinks you're trying to make a general birth gain trait, like Genius or Clubfooted.

Try making your code look like this:

bloodline00 = {
   congenital = yes
   birth = yes

   health = 1
   fertility = 0.5
   vassal_opinion = 10
}

You've already told the game that 1 it's congenital and 2 the only way to get it is from birth. Leaving 'inheritance chance' in is redundant for what you want to accomplish, i believe.