Betrayal at house on the hill question about monster turns
The traitor does not get an "extra" turn. Rather, he gets a turn to control his own character, and then the monsters get a turn, in which the traitor controls what they do. So if there are no monsters in a given scenario, then the traitor just takes his normal turn, once, and nothing happens on the "monster turn".

Rule quote:


  After the traitor’s turn, any monsters
  controlled by the traitor get a monster turn. (This means that the traitor gets two turns: one
  for his or her actions and one for the monsters.) Then the first hero to the left of the traitor
  takes a turn, and so on.


So while it does describe the traitor as getting "two turns", it is also clear that the "second turn" is the monsters' turn, not actually the traitor's turn.