The Slav Defense is the opening characterized by the moves 1.d4 d5 2.c4 c6.

The Slav Defense is the opening characterized by the moves 1.d4 d5 2.c4 c6. In this opening, Black attempts to hold onto the c4-pawn after accepting with b7-b5. White may prevent this with a2-a4, but this leads to a hole on b4, which is a key theme in the Slav. White aims to create a big center, while Black expands on the queenside and captures the b4-square.