ни пуха ни пера!

ни пуха ни пера!  {interj.}

ni `pukha ni pe`ra

 {literally} (wish you) neither fur, nor feather!

~Break a leg (Tnx to !plexuz =) )

~Good luck!

Wishing good luck, success to smb. in sth.

Usually an unalterable interjection.

 {origin}

The phrase was used as an indirect (negative) farewell "spell" said to hunters leaving for a hunt and aiming to spoof and scare devilry.

It was believed that direct good luck wishing could put the evil eye on the hunters and overlook the luck.

A rude reply — "К чёрту!" (Go to devil!) should make the hunter even more safer.