Pilnmēness nogurdinātie - break somebody's leg!

Break a leg is a well-known saying in theatre which means "good luck". It is typically said to actors before they go out onto stage to perform.
The expression reflects a theatrical superstition in which wishing a person "good luck" is considered bad luck. The expression is sometimes used outside the theatre as superstitions and customs travel through other professions and then into common use. // wikipedia