Philidor Defence

Black defends their e5 pawn with 2...d6, sparing a piece from being saddled with the job.

Though solid, this is considered a more passive reply than 2...Nc6, as Black does not develop a piece and Black's pawn chain will get in the way of developing their dark square bishop.

3. d4 is the main line, threatening to immediately crack open the centre with dxe5. White imagines a continuation like 3...Bg4?! 4. dxe5 dxe5? 5. Qxd8+ Kxd8 6. Nxe5 Be6 +- (White is up materiel and controls the centre, while Black has lost castling rights).

After 3. d4, Black's best approaches are to give up their centre and open the game with 3...exd4, the Exchange variation, or to hold on to e5 and keep the tension with 3...Nd7, the Hanham variation. Black's most Romantic reply is 3...f5?!, the Philidor countergambit.

3. Bc4 is an alternative for White. White may just follow with d4 anyway and transpose, or they may wish to play less confrontationally with d3, ensuring their bishop isn't hemmed in by their pawn chain first.

3. Nc3 is another alternative, followed by either Be2, intending to castle short, or Bf4 and Qd2 to castle long.

2...d6 was recommended as an alternative to defending the pawn with 2...Nc6 by 16th century chess theoretician Ruy López de Segura, in order to avoid the reply 3. Bb5 (i.e. the Spanish opening) which he believed favoured White.

It is named for François-André Danican Philidor, the 18th century chess master, who advocated 2...d6 with the continuation 3. d4 f5?!, the Philidor countergambit, to assault White's centre. Philidor disliked moves like 2...Nc6 for impeding the advance the c- or f-pawns that he thought was more critical, advising:

Il faut se garder de le jouer a la troisième case de fon fou, avant que le pion de ce fon, tait ete poussè deux pas, parce qu'autrement le cavalier empecherait sa marche.
[Great care must be taken not to play the Knight to his Bishop's third square, before the Bishop's Pawn has been pushed two steps because, otherwise, the Knight would prove an hindrance to the motion of the Pawn.]

—Philidor^[1]:3 [contemporary translation]^[2]:3

In 1858 it was employed unsuccessfully by the Duke of Brunswick and Comte Isougard in their game against Paul Morphy. The Opera Game, as it is called, is widely used as an illustrative game in chess pedagogy today.^[3]

Its popularity declined in the 20th century and it is no longer seen at the top levels of chess.

1. e4 e5 2. Nf3 d6

Wikipedia has related information at Philidor Defence.

• Youtube:
  • Introduction to the Philidor Defense. - HangingPawns.
  • Learn to play the Philidor Defense! - TheChessGiant.