[7] Within days of seeing the Star Trek series premiere "The Man Trap" on September 8, 1966, 22-year-old Gerrold[8] wrote a 60-page outline for a two-part episode called "Tomorrow Was Yesterday" about the Enterprise discovering a ship launched from Earth centuries earlier.

Although Star Trek producer Gene L. Coon rejected the outline, he realized Gerrold was talented and expressed interest in his submitting some story premises.

A third premise, "Bandi", involved a small being running about the Enterprise as someone's pet, and which empathically sways the crew's feelings and emotions to comfort it, even at someone else's expense.

A fourth premise, "The Protracted Man", applied science fiction to an effect seen in West Side Story, when Maria twirls in her dancing dress and the colours separate.

The script went through numerous rewrites, including, at the insistence of Gerrold's agent, being re-set in a stock frontier town instead of an "expensive" space station.

His other was an analysis of the series, entitled The World of Star Trek, in which he criticized some of the elements of the show, particularly Kirk's habit of placing himself in dangerous situations and leading landing parties himself.

Gerrold contributed two stories for the Emmy Award-winning Star Trek: The Animated Series which ran from 1973 to 1974: "More Tribbles, More Troubles" and "Bem".

This was later entered into live-action canon in the movie Star Trek VI: The Undiscovered Country when Captain Kirk and Doctor McCoy are on trial for the death of the Klingon Chancellor Gorkon.

Gerrold wrote a script for Star Trek: The Next Generation entitled "Blood and Fire", which included an AIDS metaphor and a gay couple in the ship's crew.

Gerrold wrote this script in response to being with Roddenberry at a convention in 1987 where he had promised that the upcoming Next Generation series would deal with the issue of sexual orientation in the egalitarian future.

He also had an in-joke cameo of sorts in Star Trek The Animated Series: "More Tribbles, More Troubles" where a very thin Ensign is told to seal off the transporter room area by Kirk.

Gerrold is the author of the War Against the Chtorr series of books, about an invasion of Earth by mysterious aliens: A Matter for Men (1983), A Day for Damnation (1985), A Rage for Revenge (1989), and A Season for Slaughter (1993).

[14] In approximately 2010 Gerrold was reputed to have a considerable amount of work completed on the remainder of the series, and the fifth book, A Method for Madness, was listed on Amazon with a publication date.

In his collection The Involuntary Human (ISBN 978-1-886-77869-6), he included "It Needs Salt" (as a portion of the planned but not formally scheduled Time for Treason).

Since "It Needs Salt" and "Enterprise Fish" are short stories from planned future layers of plot and character development, fans of the series are forewarned that they contain "spoilers".

After his early success with "The Trouble with Tribbles" Gerrold continued writing television scripts (mostly for science fiction series such as Land of the Lost, Babylon 5, Sliders, and The Twilight Zone).

In 1999, he contributed a short piece to Smart Reseller magazine predicting that cell phones could evolve into devices he called "Personal Information Telecommunications Agent", and described a feature set very similar to modern smartphones: I've got a cell phone, a pocket organiser, a beeper, a calculator, a digital camera, a pocket tape recorder, a music player, and somewhere around here, I used to have a color television.

The acronym also can stand for Pain in the Ass, which it is equally likely to be, because having all that connectivity is going to destroy what's left of everyone's privacy.Gerrold wrote the non-fiction book Worlds of Wonder: How to Write Science Fiction & Fantasy, published in 2001.

The Martian Child is a semi-autobiographical novel, expanded from a novelette of the same name, based on the author's own experiences as a single adoptive father, with most of the key moments drawn from actual events.

The novelette won both the Hugo and Nebula awards, and a movie version was released in November 2007, with John Cusack playing the adoptive father.

Although not necessarily canon, there are hints that it ties into the War Against the Chtorr universe, with everything from the plagues to the rumored appearance of a giant purple worm (similar cross-universe tie-ins occur in Gerrold's Trackers books).

Jumping Off the Planet received the 2002 Hal Clement (Young Adult Award) for Excellence in Children's Science Fiction Literature.