411 REFERENCE · Wikibooks
Chess Opening Theory/1. d4/1...Nf6/2. Nf3/2...d5
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Queen's Pawn Opening D03-D05
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.
Theory table
1. d4 Nf6 2. Nf3 d5
3
4
5
Queen's Gambit
c4e6
Nc3e6
Nf3Be7
=
Colle System
e3-
Nf3-
Bd3-
=
<tr>
g3c6
Bg2Bf5
O-Oe6
=
<tr>
London System with
an early Nf3 before Bf4
Bf4
=
Torre Attack
Bg5Ne4
Bf4c5
e3Qb6
=
References