The Zukertort Opening is a chess opening named after Johannes Zukertort that begins with the move:1Nf3...Sometimes the name "Réti Opening" is used for the opening move 1.Nf3, although most sources define the Réti more narrowly as the sequence 1.Nf3 d5 2.c4.
The most common responses for black are:1...Nf61...d51...c51...g61...f51...e61...d6