The Stonewall defense or attack is a variation of the Queen’s Pawn Game, and is generally characterized by White playing his pawns to d4 & e3, playing Bd3, Nd2, and then playing Pawns to c3 and then f4; although the moves are not always played in that order. The Stonewall is a sytem White heads for a very specific Pawn formation, rather than try to memorize long lines of different variations.