This idiom is a theatrical superstition used to wish performers good luck by paradoxically wishing them harm, as if saying ‘good luck’ brings bad fortune. It conveys encouragement or camaraderie, primarily used in entertainment or performance contexts to boost morale. The phrase carries a tone of humor, tradition, or irony, reflecting cultural values of superstition and the human tendency to defy fate. Its imagery of injury evokes a playful contradiction, resonating in scenarios like plays or presentations. The idiom fosters support, making it a quirky metaphor for wishing success.

The phrase likely originated in early 20th-century American theater, possibly tied to Yiddish or vaudeville slang, with ‘breaking a leg’ meaning to bow (curtsy) or earn applause, as noted in theater memoirs. Its earliest recorded use appears in *Variety* (1920s), for actors. The idiom gained traction in the 1940s, amplified by Broadway and films, notably in *42nd Street* (1933). Its adoption, primarily in the U.S., stems from its theatrical charm and superstitious appeal, with use in the U.K. and Australia.