This is the main line of the Pirc Defence. Black immediately challenges the White center with his knight, which forces White to protect it. White has several options. Each one has its pluses and minuses. Black will, usually regardless of what White plays, play 3....g6 next and 4....Bg7. Fianchetto on the fourth move, however, is not always obligatory. In the systems with 4. Bd3 or 4.f3 Black often delays this thematic move, in order to discourage Bh6. Instead, he opts for queenside expansion with ...c6 and ...b5.