pitfall is 3...c6 4.Nf3 d5 5.Bb3 Bd6. White sometimes chooses the Bishop's Opening move order to transpose into the Giuoco Piano while preventing Black from playing Petrov's Defense. For example, 2...Nf6 3.d3 Nc6 4.Nf3 Bc5 reaches the quiet Giuoco Pianissimo. The Urusov Gambit is named after Russian Prince Sergey Semyonovich Urusov (1827–1897). After 2...Nf6 3.d4 exd4 (3...Nxe4 4.dxe5 gives White some advantage) 4.Nf3, Black can transpose to the Two Knights Defense with 4...Nc6, or can decline the gambit with 4...d5 5.exd5 Bb4+ 6.c3 (6.Kf1 is recommended by Michael Goeller, winning a pawn at the expense of castling rights) 6...Qe7+ 7.Be2 dxc3, when 8.bxc3 and 8.Nxc3 both offer approximately equal chances. Instead, Black can accept the gambit with 4...Nxe4 5.Qxd4 Nf6 (5...Nd6 6.0-0 gives White an overwhelming attack), and White will continue with Nc3, Bg5, Qh4, 0-0-0, and usually intends to meet ...0-0 and ...h6 with the piece sacrifice Bxh6, exposing the black king. Black has a solid position with no clear weaknesses, but White has attacking chances and piece activity as compensation for the pawn. The Urusov Gambit is also occasionally reached via the Petrov Defence after 1.e4 e5 2.Nf3 Nf6 3.d4 exd4 4.Bc4. The Boden–Kieseritzky Gambit is named after English player and chess writer Samuel Boden and Lionel Kieseritzky. Boden published the first analysis of it in 1851. Opening theoreticians consider that after 2...Nf6 3.Nf3 Nxe4 4.Nc3 Nxc3 5.dxc3 f6, White's attack is not quite worth a pawn. The game may continue 6.0-0 Nc6 (not 6...Be7? 7.Nxe5! with a tremendous attack, but 6...d6 is also ) 7.Nh4 g6 8.f4 f5 9.Nf3 (9.Nxf5? d5!) e4 10.Ng5 (10.Ne5 Qe7! threatening Qc5+ is strong) Bc5+. In practice, Black's lack of and inability to castle can prove very problematic. Safer for Black are Paul Morphy's solid 5...c6 6.Nxe5 d5, returning the pawn with equality, and 4...Nc6 (instead of 4...Nxc3) 5.0-0 (5.Nxe4 d5) Nxc3 6.dxc3 Qe7! when, according to Bobby Fischer in My 60 Memorable Games, "White has no compensation for the Pawn." Black can also decline the pawn with 3...Nc6, transposing into the Two Knights Defense. He must, however, be willing to offer a gambit himself after 4.Ng5. White may invite an offshoot of the Boden–Kieseritzky Gambit with 4.0-0 Nxe4 5.Nc3. Irregular move orders are 2.Nc3 (Vienna) Nf6 3.Bc4 Nxe4 4.Nf3 and 2.Nf3 Nf6 (Russian or Petrov Defence) 3.Bc4 Nxe4 4.Nc3. Summary after 2...Nf6 3.Nc3 (Vienna Game, by transposition) 3.d3 3.d4 (Ponziani's Gambit)