Chess Opening Theory/1. d4/1...Nf6/2. Nf3/2...d5

=Queen's Pawn Opening= White's main options:
 * 3. c4 - Direct transposition to Queen's Gambit.
 * 3. e3 - Often signals a move toward the Colle System, though it can still transpose back to QG.
 * 3. g3 - The fianchetto is quieter but will either transpose or tend toward a Catalan.
 * 3. Bg5 - The Torre Attack. If white's plan is to double black's pawns by exchanging the bishop for the f6 knight, this is independent. Otherwise it should transpose into typical QGD lines.

A move like 3. Nc3 is certainly not bad, but it doesn't put much pressure on black. White's c-pawn plays a key role in control of the center, and moving the knight to c3 earlier usually allows black easy equality. Also 3. Bf4 can be played, leading into the London System.

Theory table
'''1. d4 Nf6 2. Nf3 d5'''