The Caro-Kann – Main Line arises after 1.e4 c6 2.d4 d5. ECO code: B12.

This is the standard position of the Caro-Kann Defence. Black challenges the e4-pawn with d5, and the game's direction depends on White's third move: 3.Nc3 or 3.Nd2 (leading to the Classical or Modern Variations), 3.e5 (Advance), 3.exd5 (Exchange or Panov-Botvinnik), or 3.f3 (Fantasy).