Chess Opening Theory/1. d4/1...Nf6/2. c4/2...g6/3. Nc3

= King's Indian Defence = White intends to play e4 with this move. Developing this knight first also keeps options open for being able to play multiple lines against the King's Indian.

One of Black's most powerful weapon here is the Grünfeld Defence with /3...d5/. The main variation, 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 leads to a typical hypermodern situation where White has a powerful center that Black will have to attack from a distance with their dark-squared bishop and a ...c5 pawn break.

/3...Bg7/ and /3...d6/ stick to the classical ideas behind the King's Indian, another venerable and popular opening.

Theory table
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'''1. d4 Nf6 2. c4 g6 3. Nc3'''