Chess Opening Theory/1. e4/1...e5/2. Nf3/2...d6/3. d4/3...Nd7/4. Bc4/4...exd4

Black trades away White's d4 pawn. This allows Black to develop their knight and bishop without facing dxe5, which would open up a range of tactical possibilities for White.

White has two ways to recapture the pawn, with the knight, 5. Nxd4, or the queen, 5. Qxd4. Both are viable: if White intends to long castle, 5. Qxd4 might be preferred.

After recapturing, White is ready to castle and bring out their remaining minor pieces, and Black must catch up in development. Black intends ...Ngf6, ...Be7, then ...Nb6 to open up a line to develop the queen's bishop. While White's bishop is on c4, ...Nb6 comes with tempo.

After either 5. Nxd4 or 5. Qxd4, it's important that Black develops 5...Ngf6 before ...Be7, otherwise, White has a tactic involving Bxf7+! and the threat of Qg4.

When contributing to this Wikibook, please follow the Conventions for organization.

Wikipedia has related information at Philidor Defence.

• Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.

• Schiller, Eric (2002). Standard Chess Openings. ISBN 1-58042-048-6.