Austrian Attack

The opening is a variation of the Pirc Defence. After 4...Bg7, typical continuations include the main line 5.Nf3 0-0, an immediate kingside attack with 5.e5 Nfd7, or a queenside counterattack with 5.Nf3 c5.
 
The Pirc Defence is one of several hypermodern responses to the opening move 1.e4. The aim of the Austrian Attack is to take advantage of Black's hypermodern approach by establishing a broad pawn centre early in the game. The general strategy for White is to use the pawn on f4 to support a breakthrough with e4–e5. Black will often castle early and attempt to find counterplay with c7–c5, or in some cases, e7–e5, or the development of the queenside knight.