The Bishop's Opening is a chess opening that begins with the moves: 1. e4 e5 2. Bc4 White attacks Black's f7-square and prevents Black from advancing the d-pawn to d5. By ignoring the beginner's maxim "develop knights before bishops", White leaves its f-pawn unblocked, preserving the possibility of f2–f4. The f2–f4 gives the Bishop's Opening an affinity with the King's Gambit and the Vienna Game, two openings that share this characteristic. The Bishop's Opening can transpose into either of these openings, and in particular a favorable variation of the King's Gambit, but with care Black can circumvent this. Transpositions into the Giuoco Piano and the Two Knights Defense and other openings are also possible. The Encyclopaedia of Chess Openings assigns the Bishop's Opening the codes C23 and C24. History and use The Bishop's Opening is one of the oldest openings to be analyzed; it was studied by Lucena and Ruy Lopez. Later it was played by Philidor. Larsen was one of the few grandmasters to play it often, after first using it at the 1964 Interzonal tournament. Although the Bishop's Opening is uncommon today, it has been used occasionally as a surprise by players such as Kasparov. Nunn uses it to avoid Petrov's Defence (1.e4 e5 2.Nf3 Nf6), and Lékó played it in the 2007 World Championship against Kramnik, known to consistently play the Petrov. Weaver Adams in his classic work White to Play and Win claimed that the Bishop's Opening was a win for White by from the second move. He was unable to prove this by defeating players stronger than himself, however, and later abandoned the Bishop's Opening for the Vienna Game, making the same claim. Grandmaster Nick de Firmian, in the 14th edition of Modern Chess Openings, concludes that the Bishop's Opening leads to with best play by both sides, and notes that, "Among modern players only Bent Larsen has played it much, but even Kasparov gave it a whirl (winning against Bareev)." Main variations Because White's second move makes no direct threat, Black has many possible second-move responses. As shown below, the Bishop's Opening offers opportunities to transpose to several other Open Games. Berlin Defense: 2...Nf6 Probably Black's most popular second move is 2...Nf6, forcing White to decide how to defend the e-pawn. After 3.d3 Black must be careful not to drift into an inferior variation of the King's Gambit Declined. One continuation that avoids this