Say “break a leg” instead of “good luck.”
A person is never supposed to wish an actor “good luck,” but instead they are supposed to say “Break a leg!” Though it may seem maudlin to do so, many theater folk believe there are mischief-making spirits of the stage who use their magic to force the opposite of what you wish to happen.
Another theory comes from the idea that the word leg does not refer to an actor’s leg, but to the theatrical curtains that mask the backstage that are known as “legs.” “Breaking a leg” means you’ve crossed from the backstage into the playing area, the ultimate goal of an actor: entering the spotlight.
Another story says that in ancient Greece, the audience didn’t clap but instead stomped their feet to show appreciation. If the audience stomped long enough, they would break a leg.
Some say the term originated during Elizabethan times when, instead of applause, the audience would bang their chairs on the ground — and if they liked it enough, the leg of the chair would break.
The most common theory refers to an actor breaking the “leg line” of the stage. In the early days of theater, this is where ensemble actors were queued to perform. If actors were not performing, they had to stay behind the “leg line,” which also meant they wouldn’t get paid. If you were to tell the actor to “break a leg,” you were wishing them the opportunity to perform and get paid. The sentiment remains the same today; the term means “good luck, give a good performance.”