Great suggestions, thanks!
Initially, all the players will be 'independent'. The game is set many years after the fall of the last king, and the players are the most influential of the houses. Its assumed that they have some rabble houses sworn to them... However it is my intent that during play, one house may become vassal to another, whether through military action or political influence.
While I'm fond of the idea of levels for buildings, I don't want it to devolve into a building management game. I want the focus to be on the families and on politics. Loren's suggestion to tie something like this to familial relations, and some kind of power or influence score might be the way to go.
