A friendly e-mail I saw wishing that Alan Gura — the lawyer arguing D.C. v. Heller on Heller's side — "break a leg" reminded me of a similar Russian phrase, which my family always used to wish me luck: "Ни пуха, ни пера," pronounced "Nee pookha, nee piera," which literally means "Neither down nor feathers."
The explanation I heard was that it was considered bad luck to wish for good luck, so you'd wish for bad luck instead; and when a hunter went hunting for fowl, back luck would be if he came back with no birds (hence the absence of down and feathers). I've also seen the claim that hunters used "pookh" to refer to fur rather than down, so that the hunter would get a wish that he come back with neither mammals nor birds, a plausible explanation but not one my grandmother told me.
The response was also a formula: "К чёрту," which literally means "to the devil," which is to say "go to hell." So, Alan, Ни пуха, ни пера.