The theatre world has always had its own rules, language and superstitions, but have you ever stopped to wonder just why this is the case? How did the phrase "break a leg" come to mean "good luck!" and why is whistling around a stage bad luck? While these rules may be closely observed and passed down through the years, the reasons that they became rules may just surprise you. 1 - Break a Leg If you ever want to see an actor get upset, wish them "good luck" just before they go