Blood-line vs Adopted?

[MC Hamster]

Just wondering if/where the game differentiates between 'blood' sons versus adopted family members and husbands of princesses?

I'm fine with the game auto-selecting the faction heir, but I'd much prefer it stayed with the firstborn son, rather than whatever system it's using at the moment, which seems to be (I haven't really looked hard at it) the next oldest family member of the same generation or below??

Would also be nice to still be able to name an heir that's underage, and have a regent in place with him (for the sake of agents, etc).. not sure how to go with a bodyguard unit or anything... still, it seems strange that they don't seem to really push the all important 'royal bloodline'

[nikolai1962]

whatever system it's using at the moment

IIRC in RTW it was the family member with the most influence who got picked to be the new heir. My guess is they are using authority for MTW.