Chess Opening Theory/1. d4/1...Nf6/2. Bf4/2...e6/3. e3/3...d5

= London System Main Line with 3. ...e6 =

In the London System, White aims for a solid, flexible pawn structure and develops their dark-squared bishop early to f4.

When Black responds with 1. d4 Nf6 2. Bf4 d5 3. e3 e6, they aim for:


 * A solid pawn chain in the center while also developing their pieces.
 * A straightforward setup that avoids complex theory, making it suitable for amateur players and those familiar with Queen's Gambit Declined structures.
 * Achieving a comfortable position and, rather than going for an immediate pawn break, they plan for one in the midgame, allowing for a more positional and strategic battle.

This setup can result in a closed game, and Black might look to expand on the queenside or prepare a central break with ...e5 or ...c5 later in the game. Overall, the setup is about achieving a solid position without entering into deep theoretical battles and also keeping options open for different plans based on how White proceeds.

Theory table
. '''1. d4 d5 2. Bf4 Nf6 3. e3 e6'''