Playing a game as the Roman Empire, and subsequently getting really tired of seeing Egypt start owning random provinces in Britannia, or Pontus owning random provinces in the middle of Africa. I've tried making vassal inheritance illegal the default for all and preventing them from switching away from it in the law files, but it still happens. This is a big killer in immersion and fun for me. I am not even talking about wars between them just straight up middle of Spain you'll see a little "Egypt" pop up. Is there any way to stop this and have vassals keep 'clean' borders?