Chess Opening Theory/1. e4/1...e5/2. Nf3/2...d6/3. d4/3...f5/4. dxe5

=Philidor Counter-Gambit= The situation is unclear. Black can play 4...fxe4, forcing the white knight move. Also to be considered is 4...Nc6 controlling the d4 and e5 squares.

Theory table
'''1. e4 e5 2. Nf3 d6 3.d4 f5 4.dxe5'''