History NewPowersAsThePlotDemands / LiveActionTV

** Perhaps the most grating example in the series is Cecile Horton, who gains telepathy mid-pregnancy, then afterwards she shifts to being an empath which also makes her a LivingLieDetector, then she gets the power to manipulate emotions, then by the final series she gains regains telepathy and also gains telekinesis and flight.

* A number of abilities in ''Series/{{The Flash|2014}}'' seem to be of this kind. Some are used only once and then forgotten. For example, in Season 3, Caitlin uses her Killer Frost powers to make it snow on Christmas (it previously rained). It's not specified how she suddenly became the next Weather Wizard, and she never does anything of the sort again. In Season 4, Barry somehow gains the ability to pull other people into his frame of reference, such as when he has a long conversation with Iris, while a split second passes around them. When Iris asks how he did that, he tells her he doesn't know (previously, someone had to tell him he could do something first, and it usually took a try or two). Barry also somehow can move at superspeed without causing huge winds to throw random paper around him, if he really wants to.

* [[TheSpock Spock]] was a master of this. In various episodes (and movies) of ''Franchise/StarTrek'', he suddenly demonstrated the abilities of mind-melding, the Vulcan nerve pinch, a light-protective nictating membrane, the ability to go into a deathlike trance at will, and a detachable soul that would allow him to later come back from the dead. Absolutely none of these were telegraphed before he absolutely needed them (as opposed to say, Wesley Crusher being told he had a great destiny by the Traveler long before he pulled the ability to stop time [[AssPull out of his ass]].) This, plus his refusal to admit that his parents were the ambassador and his wife or that he had to have sex with his wife or he'd die, make it ''almost'' plausible that as of ''Film/{{Star Trek V|The Final Frontier}}'' he could have had a long-lost half brother he never told anyone about. Almost.

* ''Series/{{Believe}}'': Bo's PsychicPowers tend to do whatever is needed for the plot like lighting up a tunnel in the "Collapse" episode or creating the illusion of a wall in "Revelation" without any hint that she could do that beforehand.

** [[RobotDog K-9]] was written out of the series after he acquired so many abilities that it was difficult to come up with plots that couldn't be resolved in a few minutes by K-9. Some episodes deliberately incapacitated K-9 to take him out of the story.

*** The series regularly gives the TARDIS new abilities as the plot demands, to the point where she could have her own page.

*** The Fourth Doctor reveals he has a "respiratory bypass system" in [[Recap/DoctorWhoS13E3PyramidsOfMars "Pyramids of Mars"]], meaning he can go for much longer without needing to breathe. He also now possesses telekinesis ([[Recap/DoctorWhoS17E2CityOfDeath "City of Death"]]), experiences sudden visions of the future ([[Recap/DoctorWhoS14E3TheDeadlyAssassin "The Deadly Assassin"]]) and can hypnotise most people effortlessly just by [[HypnoticEyes getting them to look into his eyes]] (though to be fair, the Master had previously displayed a similar ability). He also picks up some bizarre, uselessly specific powers to get out of plot corners that will almost certainly never come up again — [[MakeMeWannaShout the ability to shatter windows with a shout]] ([[Recap/DoctorWhoS16E5ThePowerOfKroll "The Power of Kroll"]]), the ability to breathe helium without it affecting his voice ([[Recap/DoctorWhoS14E5TheRobotsOfDeath "The Robots of Death"]]) and the ability to shut down his body processes and go into a state of temporary biological death ([[Recap/DoctorWhoS17E6Shada "Shada"]]). Some ExpandedUniverse stories (e.g. ''The Death Pit'') even have him able to read anyone's mind without even trying if they're thinking loudly enough, and contemporary-to-the-series comics have him able to psychically detect his companion's pain to the point where the villain specifically tortures Sarah so her pain can send a signal to the Doctor. In "City of Death" he gains the implicit ability to ''fly'' for a gag — [[ForgotAboutHisPowers never used again, of course]]. [[CoconutSuperpowers Though almost certainly for the best.]]

** ''Series/KamenRiderFourze'' has the supporting villain Kosei Hayami spontaneously gain the power to see an individual's Zodiarts potential seconds before his boss is about to [[YouHaveFailedMe punish his repeated failures]]. Since the entire plot is about the villains trying to find the Zodiarts who line up with the Western Zodiac, this new power lets them fit the remaining five monsters into the last 14 episodes.

* ''Series/{{Charmed}}:''

** In ''Series/MightyMorphinPowerRangers'', they were concerned that Tommy (who had limited power) could keep his powers throughout an upcoming battle, and Tommy suggested that he uses the Sword of Power. They know about it and are able to call upon it, despite it never being used or even mentioned before or sense.

** Series/KamenRiderZeroOne has a supercomputer equipped with a 3D printer that, at least in the first story arc, routinely analyzes Zero-One's battles and is able to whip up new weapons or {{Transformation Trinket}}s as countermeasures when needed. This even extends to making an exact copy of another Rider's upgrade item so both him and Zero-One can enhance themselves at once. But this actually leads to a plot hole when one of those trinkets gets stolen and is used by an enemy for most of the arc - why couldn't the computer just print a replacement?
* Done in one of the ''Series/KamenRiderDouble'' movie by [[spoiler:Double himself, in his Cyclone Joker Gold Xtreme mode. It's only for a few minutes, enough time to to stop falling off Fuuto Tower and defeat the villain.]]

** Series/KamenRiderGhost starts gaining new emotion-based powers after surviving the destruction of his SoulJar. These changes are eventually revealed to be part of his transformation from a ghost into a deity.

** An interesting subversion occurs in ''Series/PowerRangersInSpace'', in which Andros has been carrying his own Battlizer for a good portion of the season, using it only to power up his attacks and control the Delta Megazord. Eventually Carlos asks him why he's never used the highest power setting on the device, to which Andros replies that he worries that it may be ''too'' powerful. Later, in a battle in which he is unable to morph, the final setting is activated and he becomes the Red Battlized Ranger for the first time. Mind you, Andros isn't the one who activated it--it was pressed by a little girl nearby. For all she knew, the setting ''was'' too powerful and it could have blown them all up.

** In general, the whole series operates this trope at a higher level. If the writers need a new power, they don't give it to an existing character, but introduce a new character with the desired ability. One of the benefits of LoadsAndLoadsOfCharacters is nobody much notices a few more or less.

** The Doctor's use of this trope pales in comparison to his sonic screwdriver, which has thousands of settings and started off being used to ''put in screws''. A list of everything it has done would be as long as this page. The original series wrote it out as it was becoming omnipotent and the writers used it as a get-out-of-trouble-free card too much. TheMovie brought it back, and the new series imposed some definite restrictions on its abilities so as to have a reason ''not'' to let the Doctor use it to get out of anything. It's still pretty handy, though.