Created By: Glyndwr on January 30, 2012 Last Edited By: Glyndwr on February 3, 2012

One Episode Rule

There are rules and there are super-duper rules which apply in ONE episode

Name Space:
Page Type:
sub-trope of Omniscient Morality Licence sub-trope of Retcon.... Needs More Examples

The Story has rules; in one episode, they change the Rules and never mention that change again, evah!

Live-Action TV
  • The Trope Namer Star Trek Voyager: "The Disease". after a million episodes of Kirk explaining to Green-Skinned Space Babe the thing we humans call Love, and Ryker explaining Love to both space babes and space dude and Paris reverting to explaining Love to space babes, Harry Kim sleeps with ONE alien, so Janeway asspulls the minus infinity directive that Star Fleet forbids all fraternization. This regulation is never mentioned again.
    • Justified in "The Omega Directive" because it was the only episode when they encountered Omega particle.
    • Retcon-ned: TNG rules defined Warp 10 as the maximum, Janeway and Paris travelled at Warp 20, turne into salamanders and the Doctor healed them. Never mentioned again.
  • Zig-zagged in Buffy the Vampire Slayer: Season 3, there is a big deal that Slayers are forbidden to kill Humans, but the rules about Humans killing Humans are deliberately left vague; Season 5, Buffy kills 10 Knights of Byzantium; resolved in season 6 YMMV.

  • Harry Potter: books 4-7 insist that Crucio, the torture spell is Always Chaotic Evil, book 7 finale insists that torture is gallant if a Gryffindor does it.
Community Feedback Replies: 11
  • January 31, 2012
    There was another Voyager where a directive above the Prime Directive was mentioned, and then never again after that. It's basically, "if you come across an Omega Molecule destroy it, no matter what the cost to the native population." Admittedly Omega Molecules are exceedingly rare, so it's not that surprising (In Universe) that it'd never come up again that we've seen.
  • January 31, 2012
    The Star Trek Voyager episode mentioned in the OP was "The Disease", and the one in randomsurfer's post was "The Omega Directive"
  • January 31, 2012
    To clarify, the Starfleet fraternization rule just deals with unknown alien races (not "all fraternization"). A human mating with a Vulcan (or Klingon, or so on) can do so in private, since Federation science has studied such combinations and declared them safe. In the episode in question the alien species was unknown. There could be (and were) unforseen consequences that could very well be dangerous.
  • February 1, 2012
    Bolleaux, Kirk's duty is to explain to all Space Babes this thing we Humans call Love, as is Ryker's duty. In That One Episode, Ryker's duty included explaining Love to a Space Dude. Tom's duty reverted to the original directive, so Paris only explained this thing we Humans Call to Space Dudes in the EU.

    If Janeway, had told Kim that Space Babe was a privilege for ranking officers, that would have fitted established canon.

    Janeway invented the No Faternization EVAH rule in one episode and it was never mentioned again.
  • February 1, 2012
    This Needs A Better Name for several reasons, not the least of which are that the name tells us nothing about what the trope is and the fact that there's already a movie called Alien.

    Off the top of my head, how about Single Episode Rule? Or BLAM Rule?

    Also, the trope you mislinked to in the write-up is Green Skinned Space Babe.
  • February 1, 2012
    Vitally Important This Episode?

    Wait, that doesn't quite work.
  • February 1, 2012
    Thanks for the correct spellig of Space Babe, I tried a million versions and in kept coming up In Red.
  • February 1, 2012
    "One Episode Rule" and "Single Episode Rule" seem like actually having one episode.

    Important In This Episode Only?
  • February 1, 2012
    Ugh, be glad the title was changed from "Trope Namer is the only example I have which this entire YKTTW is just an excuse to bitch about".
  • February 2, 2012
    @Glyndwr: At the start of the YKTTW, were you looking for Omniscient Morality License? Also, the title at the top should have spaces. Furthermore, you forgot the bullet point and the slash for the namespace for the Harry Potter example, and it's called the Cruciatus Curse, "Crucio" is just the incantation, and you should probably Pot Hole it to Agony Beam.

    You might also want to make the Star Trek Voyager example sound less complainy. And the warp thing is wrong in many ways: They reached warp 10, not 20, and of course it wasn't mentioned again because they didn't do the warp 10 thing again. Why would they refer to it again when that plot was already wrapped up?

    Hell, the description could probably also stand to be a little more eloquent. It's a trope, not a forum post.
  • February 3, 2012
    ^There was another episode not long after "Threshold" (within a year, I think) in which Paris explicitly says "I've never travelled at Warp 10 before."