sub-trope of Omniscient Morality Licence
sub-trope of Ret Con
.... 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.
- Ret Con-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.