Czech Variation, with Nc3

The Czech Variation with Nc3 arises after 1. d4 Nf6 2. c4 d6 3. Nc3 c6. Instead of striking with 3...e5 or developing a bishop, Black spends the move on the c-pawn. It controls d5 and b5 and leaves room for either the usual ...e5 break or an advance on the queenside, so Black keeps several plans open for another move. The same position can also come from 1. d4 Nf6 2. c4 c6, when Black follows with ...d6 instead of the Slav move ...d5.

White's most common answer by far is 4. e4. It takes the full center and accounts for about half the games in the database. 4. Nf3 is the main alternative and leaves the e-pawn's role open for now. 4. Bg5 pins the f6-knight and is less common, and it scores slightly worse for White than the other two moves. The engine gives White a slight edge, chiefly from the extra space, yet on Lichess the results are close to even. With ...Nbd7 and ...e5 in reserve, Black usually aims for a compact setup, and the play tends toward slow maneuvering rather than early tactics.