The character of Tasha Yar was originally to be a Latina named Macha Hernandez, inspired by the tough female marine Vasquez in Aliens. In fact, Jenette GoldsteinJenette Goldstein (who played Vasquez) auditioned for this character, and later played the Enterprise-B science officer in Star Trek: Generations.
Deanna Troi was nearly written out after the first season and in fact is absent from many year one episodes. But after both Tasha Yar and Dr. Crusher were written out, Troi was kept.
Each of the three live-action [Star Trek] series after the original [Star Trek] has had a cameo appearance by a character from its predecessor series in its premiere episode: [Star Trek: The Next Generation] had Dr. McCoy.
Near the end of the episode {Symbiosis} when Captain Picard and Doctor Crusher walk out of the Cargo Bay look in the background and you will see Tasha Yar (Denise CrosbyDenise Crosby) waving at the camera, as this was the last episode she filmed before she left the first time.
The 1988 episode {The Neutral Zone} was a milestone in the history of [Star Trek] by establishing that the first season of [TNG] took place in the year 2364. This was the first time an exact calendar date was provided for a Trek episode. All Star Trek episodes, chronologies, novels and background information since 1988 have been calculated from this date.
Originally, Data was to be the Chief Science Officer of the Enterprise, (much like Spock was on the original [Star Trek]) and sport a blue tunic. However, the blue tunic clashed with his android make-up and the idea was scrapped. Data was re-assigned as Chief Operations Officer of the Enterprise and sported a gold tunic for all seven seasons (except for the two-part episode [{Chain of Command}] in which he is promoted to first officer and wears a red tunic).
The diamond-shaped chrome shelf unit in the Farpoint Mall set comes from Kirk's apartment in Star Trek: The Wrath of Khan.
The Ferengi were originally introduced with the intention of making them the main, recurring adversaries in the series (very much as the Klingons were in the original series). However, audiences found the Ferengi too comical to take seriously as potential foes, and the race were gradually refined into the more (usually unintentionally) comical characters as later typified by Quark in [Star Trek: Deep Space Nine]. The Borg would eventually become infamous as [TNG]'s ultimate nemesis.
Gene RoddenberryGene Roddenberry's original scripts for [TNG]'s premiere story, {Encounter at Farpoint}, did not include any scenes set in the Enterprise's engine room. When he learned that Paramount was therefore refusing to pay to build an engine room set, he revised the scripts to include the engine room.
The death of Tasha Yar in {Skin of Evil} marked the first (but not the last) time a continuing Trek character was killed off. (Spock doesn't count as he was revived).