@jayboman1579 said
What the correct idea for black after 1d4 d5 2.c4 c3 3.c5 ?
I'm not playing it right now, but have an irrational (probably) fear of it. What should I do next?
The white push 3.c5 in a d4-pawn game is a theoretical error, as the high win ratio for black indicates. This is much too early for such an advance, as it releases the tension, does not hamper black's further development, leaves the d4-pawn potentially backward, and does not gain any significant territory in the black camp.
Unlike the apparently similar advances for white (e5) in the Caro-Kann and French Defense, which
do cramp black's development and gain significant ground.
Caro-Kann Advance variation:
Analogously in the French: