1. a phrase wishing someone good luck before a performance. All the best. Best of luck
Good luck! Break a leg!
The phrase 'break a leg' is used by actors and performers to wish each other luck backstage before a performance. In many places in the world, it is considered bad luck to wish someone 'good luck' before a performance. You say 'break a leg' to someone before they give a speech or talk, or before an exam or another important moment. You can use this in any situation instead of saying 'good luck', however, it is slightly less formal.