Why do we say, “Break a leg!” to wish someone else good luck? The popular explanation is that the “leg” being referred to is not the human kind, but rather the curtain that hangs in the wings, masking the side wings of the stage. Breaking a leg means you have broken past this barrier and made it successfully onstage as a performer. Some say the phrase dates back to early Vaudeville shows, when performers would wait backstage until it was decided in the moment if their act would go on that day. If they were sent on stage, they had broken the leg.
—Nook Schoenfeld
