Good luck in Russian

Russian wishes drop желаю (I wish you) and leave the wished thing in the genitive: удачи, счастливого пути, спокойной ночи all follow the same machine you have met on the good-night page.

Ни пуха ни пера is anti-jinx logic: wishing a hunter no down and no feathers so the spirits do not spoil the hunt. Answering спасибо breaks the spell; the only correct reply is к чёрту. Use it before someone's exam and watch them grin.