Blackmar-Diemer Gambit (BDG)

2...dxe4

White has given up his king's pawn, in hopes of an aggressive game. Since there is no way White can win a pawn back immediately, he can expect this set-up most times he plays the Blackmar-Diemar Gambit. The best move for White would be Nc3, putting pressure on the e4 pawn. It also prepares the move f3, as 3.f3 is well met by 3...e5!, with an edge for black. One example: 4.dxe5 (other moves are even worse, for example 4. fxe4 Qh4+ and Qxe4 with an extra pawn and an attack, or d5 Nf6 c4 c6 when d5 will soon fall) Qxd1+ Kxd1 Nc6 fxe4 (f4 Bg4+ Ne2 O-O-O+ with a winning attack) Nxe5 with an obvious advantage. Black normally plays 3...Nf6, though 3...f5 and 3...Bf5 are interesting ways to avoid mainline theory. Now, if f3 e5?, dxe5 gains a tempo on the knight. Sometimes Bc4 is played, to hopefully trap Black quickly with a variation of Scholar's Mate.