Chess Opening Theory/1. d4/1...Nf6/2. c4/2...c5

= Benoni Defence = Black threatens to exchange the c pawn against a central pawn. The objectively best solution for White is to advance the pawn and play /3. d5/, gaining space in the center, however it allows black to gain dangerous pressure by 3...e6. To avoid this, White may play /3. Nf3/, protecting the pawn. This move allows Black to exchange the pawns or to increase pressure by playing 3...e6. Additionally, 3.Nf3 may transpose to a Maroczy Bind Sicilian. The last option is /3. e3/ but this leads to a blocked game for white (both bishops are blocked by pawns and Black will get a lead in development). Notice that if white takes with 3. dxc5 Black will not lose material. With the moves 3...Na6 or 3...e6, Black will equalize easily.

Theory table
.

'''1. d4 Nf6 2. c4 c5'''