The original concept involved a group of Humans and Cardassians, although this was changed to the Ennis and the Nol-Ennis so it would not look like the main characters had chosen sides.
Stunt coordinator Dennis Madalone directed the first two days of the shoot, as they solely consisted of action sequences, which director Paul Lynch was not interested in handling. Executive producer Rick Berman disapproved of this, feeling that Lynch had abdicated his duty as director, and decided not to hire him to work on the franchise again.
In an outtake from the first scene on the runabout, Avery Brooks delivered a line "We'll be entering the wormhole in about an hour" instead of the scripted time of a minute. Brooks smiles and Camille Saviola (Kai Opaka) says "Well, I ain't got that long, I've got about fifteen minutes!".
Tom Morga designed the weapons in this episode. He did so by taping together a cardboard blade, a ball and an old tool handle.
This episode was one of the first to define the United Federation of Planets. Commander Sisko's response to Zlangco's question was that it "is made up of over a hundred planets who have allied themselves for mutual scientific, cultural and defensive benefits. The mission that my people and I are on is to explore the galaxy". Jean-Luc Picard later says something similar to Lily Sloane in Star Trek: First Contact (1996).