Hi Mapalo. Ive always understood it as wishing someone good luck. And I remember it being used a lot more a few decades ago. A similar concept is the "jinx" which is the idea that - if one wishes something good to happen, then as a consequence something bad will happen (opposite). So, to not "jinx" the situation, ppl say "break a leg" so that the opposite can happen. hope this helps!

Nowadays It means do a good job and good luck, in theater back in the day if the main star was injured the under study got their chance to have the spot lot, so in essence the main stars misfortune became the under studies good luck.

Good luck 🙂

It means “Good Luck”