Chess Opening Theory/1. e4/1...e5/2. f4/2...d5/3. exd5

= Falkbeer Countergambit =

3.exd5
This is the normal response, capturing the pawn on d5, as black is putting pressure on both the e4 and f4 pawns of white's and 3. fxe5?? loses to Qh4+!. From here, black has 3 choices:
 * 3... exf4 is the natural response, where a sample line continues 1. e4 e5 2. f4 d5 3. exd5 exf4 4. Nf3 Nf6 5. c4 c6 6. d4 Bb4+ 7. Nc3 O-O 8. Be2 cxd5 9. O-O Be6 10. Bxf4 dxc4 11. Ng5 Nc6 12. Nxe6 fxe6 13. Bxc4 Qxd4+ 14. Qxd4 Nxd4 15. Rad1 b5 16. Rxd4 bxc4 17. Rxc4, which is equal. There are multiple ways to diverge from these lines, but all usually lead to equality.
 * 3... c6!? is a new, modern response that focuses on development and the cramping f4 pawn over material. No clear verdict has been reached on this line.
 * 3... e4 used to be considered an option, but now, modern theory gives white a good game after 4. d3, and the line is a very rare sideline these days.

Theory table
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1. e4 e5 2.f4 d5 3.exd5