Similar to what happened to the gecko in FO2, what about if every location can change in a couple of ways due to quest's. And then new quests would become accesible.
not really on the same subject, id like 2 c decals in it (easy with a 3D engine)... like u could use ur smg and miss, it could punch holes in the wooden walls of the nearby building... or if there is a guy in a bar and he starts a fight, u could pull out ur shotgun and paste his brains on the near by wall/bar... that would look SO cool!!
