10 Welcome Changes Deep Space Nine Made To The Star Trek Formula
2. Animosity Between Main Characters
Another of Roddenberry's big no-nos for the series, the idea of interpersonal conflict between characters on the show was originally non-existent. Despite TOS enjoying the amusing back-and-forths of Spock and Bones, TNG was intended to feature characters without any ill will towards each other whatsoever. Though an interesting concept in theory, here is one of the many instances where the creator just doesn't know best.
The occasional row would sneak into TNG after Roddenberry's death, but where it really became a standard element of the franchise is in Deep Space Nine. It probably goes without saying that the devious Quark rubs a lot of the crew members up the wrong way, particularly the station's Head of Security, Odo. For the entirety of the series, the two polar opposites enjoy a peculiar love-hate relationship - albeit with far more emphasis on the latter.
Kira's aforementioned clashes with Kai Winn are also a prominent recurring motif, and the decision of Quark's young nephew, Nog, to apply for the Starfleet Academy is quite the point of contention onboard the station. Many other conflicts present themselves throughout the show, providing that extra level of realism to the interactions between such rich and interesting characters.