This is discussion archived from a time before the current discussion method was installed.
This is a trope that is too big for examples. Literally every TV show, movie, book... every form of entertainment uses it.
A better list might be inversions of it.
Hmm...I think the examples don't quite get the concept.
If the villain or hero legitimately adapts to the plan, than it doesn't count as It Only Works Once.
This is a case where the giant ray gun HAPPENED to be placed in a valley that can be flooded, or a wandering PTB just happened to stop by and heal the poisoned character in a Find the Cure! plot.
A better example would be in Kim Possible, when Dr. Drakkhen stopped using his Mind Control Shampoo because of bad marketing. Surely he could do something else with it? But no, it's never seen again.
Big T: A lot has changed since you wrote that. He did finally reuse it in an attempt to control the military, then of an amnesiac Kim. Luckily, note cards and Ron's new belt save the day.
Looney Toons: J Random User — your cite is correct, but note above. It still isn't an appropriate example.
Morgan Wick's two cents: The "inappropriate" examples seem common enough that either a) we should expand the definition to include them, or b) they constitute a separate trope. In many of these examples, sure, the villain or hero adapts to the plan - but not legitimately. It's forced as a Hand Wave, or comes across as a Writer on Board - or we're told that it's ineffective, but the reasons why don't make sense or are nonexistent. The V example seems to be a pretty good idea of what I'm talking about. They forced an Achilles' Heel into the Achilles' Heel that we'd never heard about before so they could keep telling the same stories.
Ununnilium: Seems like a Justified Trope version of this. Retroactive Achilles? Not Like Last Time? Neo not being able to explodify Agents in the Matrix sequels might qualify.
Licky Lindsay: is this named after the Looney Tunes gag where a character says "I have this amazing magic trick to show you, but I can only do it once" and trick involves blowing themselves to smithereens?
Kizor: Probably not, but it should have been.
Hmm....what about the 2 times that someone has tried to shoot a Dalek eyestalk in the latest Doctor Who? (In reference to a previous episode in a previous series, the Dalek says "My vision is impaired! I cannot see!". In one episode, it eventually did work (last one with Christopher Eccelstone), but only on one of multiple Daleks. Also, in the penultimate episode of season 4, someone tries it with a paintball gun, only for the dalek to dissolve the paint off, and say "My vision is NOT impaired!".
Vampire Buddha: Removed natter:
- Either way, it doesn't look like it was a good idea leaving them alive does it? Also there's Crocodile. Although his plan was a very extensive one requiring years of working in the shadows, he could just as easily redo his plans and try a take over again, maybe in another country.
*** Both Crocodile and Arlong are currently in jail, so I think they have a pretty good reason for not retrying their plans.
*** Sure, and there's also Drum (whose two Dragons looked to be more than enough to handle all the population of the once-his realm), Krieg (who was still a looming danger at the West Blue) and every Big Bad encountered by the protagonists. Hell, the twelve years old ninjas of Naruto have more balls at killing BigBads than these pirate young adults inOne Piece.
*** Actually, in the Question Corner, the author says: "So why didn't he kill him? In this era, people put their lives on their beliefs and convictions, and fight. Luffy goes into battle and destroys others' beliefs. When these enemies' beliefs are shattered, and they lose, they feel a pain as great as dying. I think that for these pirates, killing or not killing is secondary to winning or losing." They don't kill because they don't need to, and don't feel like getting their enemies' blood on their hands.
*** Also, many villains and even some Big Bads have found new things to do with their lives after their defeat. Like Wapol with his toy factory and supermodel wife. There's also Enel, who did do exactly what he'd intended to do all along, only without the parts that involve ruining and/or ending other peoples' lives (although some of the folks on the moon may disagree on the "not ruining lives" part).
*** And in any case, the general lack of death in the series just makes the occasional actual death that much more powerful.
- Either way, it doesn't look like it was a good idea leaving them alive does it? Also there's Crocodile. Although his plan was a very extensive one requiring years of working in the shadows, he could just as easily redo his plans and try a take over again, maybe in another country.
