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

The position has turned symmetrical again. White has many options to choose from, each one leading to very different opening systems.

3. c4 is the most popular, transposing into a Queen's Gambit. White may choose this move order to avoid certain openings, like the Budapest defence, which would have been playable had White not placed their knight on f3 in advance.

3. Bf4 is the second-most popular, turning the game into a London System.

3. e3 sees White going for the Colle System. This is the main move-order used by practitioners of this system.

3. g3 turns the game into a Catalan-like position, but through a less accurate move-order. Black gets to place their light-squared bishop outside of the pawn-chain without any troubles.

3. Bg5 is the relatively rare Torre Attack. Unless White tries to double Black's pawns by exchanging the bishop for the f6 knight, this is an independent line. Otherwise it will likely transpose into typical Queen's Gambit declined 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 centre, and moving the knight to c3 earlier usually allows Black easy equality.

1. d4 Nf6 2. Nf3 d5

• Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.

• Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.