When you walk into some rooms they will contain people that who you 
have to fight. To get the overall advantage over them, allow them 
chase you around the room until you get behind them. When you get 
close enough, "Advantage" will appear at the top of the screen. Not 
only will you have the advantage, you will start with full power and 
will take more of the creature's life away since you attacked from 
behind.