House Marriage Only
If a character have the trait pure-blooded, he/she can only marry his/her house member.
Pure blood is modified and can be inherited 100% if one of the parents has the trait.
Check "family marriage only"
https://steamcommunity.com/sharedfiles/filedetails/?id=3345326287
"Sibling marriage only"
https://steamcommunity.com/sharedfiles/filedetails/?id=3345816077
If you need
