In chess, artificial castling (also called castling by hand) refers to a maneuver in which a king which has lost the right to castle achieves a castled position in several normal moves, instead of the one special move.
White sees that if he recaptures with 5.Nxe4, Black responds with 5...d5, forking knight and bishop and winning back the piece. In that case, Black has not won material, but has destroyed White's center. Instead of allowing d5, White hopes to cause trouble for Black by returning the piece while depriving him of the right to castle. However, Black can easily castle artificially, for example:
5... Kxf7 6. Nxe4 Be7 7. 0-0
White castles "naturally".
Black begins castling artificially.
8. d4 exd4 9. Nxd4 Kg8 (second diagram)
Black has achieved a normal castled position (Rf8, Kg8), but in several moves. The absence of any pawns in the center indicates that king safety is of particular importance in this position. Black's development lags slightly, but he also possesses the bishop pair and a queensidepawn majority, so his position is at least equal.
In an even more common opening (a main line of the Benko Gambit, ECO A59), White uses the g2-square in an artificial castle maneuver to safeguard his king after an exchange of bishops on f1 precludes castling normally:
1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. bxa6 Bxa6 6. Nc3 d6 7. e4 Bxf1 8. Kxf1 (first diagram) 8... g6 9. g3 Bg7 10. Kg2 0-0 11. Nf3 Nbd7 (second diagram). White has completed the artificial castle maneuver of his king and is ready to continue with 12.Re1 (or other moves).
A unique and even humorous artificial castling took place in the game Heidenfeld–Hecht, played in the NiceChess Olympiad 1974:
1. e4 Nf6 2. Nc3 d5 3. e5 Ne4 4. d4 Nxc3 5. bxc3 e6 6. Bd3 c5 7. f4 Nc6 8. Nf3 Qa5 9. Bd2 Qa4! 10. Be3 c4 11. Be2 Ba3 12. Bc1? Qa5 (see diagram) White's queenside pawns were under heavy pressure, and "usual" moves such as 13.Bd2? Bb2, 13.Bxa3 Qxc3+! or 13.Qd2 Bxc1 would have all led to a loss of a pawn. So, White came up with the following unusual maneuver: 13. Kd2! Be7 14. Qe1 Bd7 15. Ke3 Now that the queen guards c3, the king can continue his journey to safety. 15... f6 16. Rf1 fxe5 17. fxe5 0-0 18. Kf2 Be8! 19. Kg1 White has "castled" in five moves instead of the usual one, but maintained material equality (although after 19... Bg6, Black was still better, and eventually won).