Since we're scraping the bottom of the barrel here, what about TNG: The Naked Now
? John D. F. Black in fact gets story credit, for TOS: The Naked Time.
I know, I know, it's adapted from a previously aired Star Trek
episode, not a previously published story, but, at least from a certain point of view
[/Obi-Wan], it's a "preexisting science fiction story". Right?
Similarly, The Motion Picture
was apparently inspired by TOS: The Changeling,
although John Meredyth Lucas received no screen credit and the screenplay was actually a direct adaptation of Phase II: In Thy Image.
To be honest, I'm unclear on the development lineage there, and why Lucas got no credit.
Additionally, according to Memory Alpha [http://en.memory-alpha.org/wiki/The_...nd_Information
Memory Alpha wrote:
Also never credited, the idea behind this episode [The Changeling] was inspired by the last episode of the original The Outer Limits. That episode, called "The Probe" (with Janos Prohaska, in a Horta-like rubber suit, and Mark Richman), featured an alien automated probe which headed for Earth after apparently encountering one of our deep space exploration devices. As in the Trek episode, the probe nearly kills everyone because of its imperative to sterilize. (citation needed)
However, they provide no citation, and I haven't seen that Outer Limits
episode, so I'm not saying it's true. In any event, no screen credit was given in that case either.
If one wants to broaden the criteria, there are episodes that are clearly beat-for-beat adaptations of other stories, that are not
science fiction, at least in cases when no credit was assigned. The foremost example here is probably TOS: Balance of Terror,
obviously (and allegedly admittedly) adapted from The Enemy Below.
How "official" an adaptation does it have to be to count? Like that ENT episode that played out very Enemy Mine
? Or that TNG that ended up having to credit Laurel K. Hamilton due to...ahem, similarities? (Although her book wasn't sci-fi, but still.)
What TNG episode in connection with Laurell K. Hamilton are you referring to?
The ENT episode you're referring to is ENT: Dawn,
right? Memory Alpha doesn't mention Enemy Mine
in the main article, because it would count as original research; someone on the talk page
brings up the similarity of Dawn
to both Enemy Mine
and Hell in the Pacific,
and the reason all that doesn't go on the main page is explained. But, if their policy rules out mention of those two films on the main page, I don't see why it would allow mention of TNG: The Enemy
or TNG: Darmok.
Frankly, TNG: The Enemy
always reminded me of UFO: Survival.
It's not a beat-for-beat adaptation, but a very similar idea.
And I guess that's the thing. There will always be similar ideas cropping up over and over, but that doesn't necessarily count as rip-off.