The Pirc Defence (correctly pronounced "peerts", but often mispronounced "perk"), sometimes known as the Ufimtsev Defence or Yugoslav Defence, is a chess opening characterised by Black responding to 1.e4 with 1...d6 and 2...Nf6, followed by ...g6 and ...Bg7, while allowing White to establish an impressive-looking centre with pawns on d4 and e4. It is named after the Slovenian Grandmaster Vasja Pirc.