The French Defence – Main Line arises after 1.e4 e6 2.d4 d5. ECO code: C00.

This is the standard French Defence position, the starting point for all main variations. Black challenges White's e4-pawn with d5, creating the characteristic French pawn tension. White's third move—3.Nc3, 3.Nd2, 3.e5, 3.exd5, or others—determines which specific variation is entered.