Uniqueness Decay

In many series, something or someone is first introduced as special - new, awe-inspiring, mysterious, utterly unique, unparalleled, or some combination of those things. Sometimes, either later in the series or in related works in shared universes, that specialness seems to fade without much explanation or get outright retconned away. The unique example becomes just one of many, the mystery somehow gets thoroughly documented, the new arrival turns out to have a long history in the area, the unparalleled turns out to be a footnote, and the awe becomes...meh.

This is a form of Continuity Drift, perhaps sometimes due to They Just Didn't Care or careless research on Long Runners. But Tropes Are Not Bad; it can be justified if enough time passes and the once unique aspect is spread due to analysis/teaching/reverse engineering. In a way, it adds fuel to the fandom who like making their own Sailor Earth.


Examples include:

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    Anime and Manga 
  • Dragon Ball:
    • The acquisition of Dragon Balls becomes increasingly trivial as the series goes on. While they were meant to be brought together only after a lifetime of searching by a very dedicated person, Bulma's Dragon Radar allows the heroes to collect them all within the span of a single story arc. Later sagas often have them acquired within the span of a single episode or even offscreen so that the heroes can deal with or clean up after the Big Bad du jour. Dragon Ball Z introduces a second set of Dragon Balls on the planet Namek, which follow a similar progression, while Dragon Ball GT adds a third set of Dragon Balls but scatters them across the entire galaxy and blows up the Earth if they're not brought back within a year. Then Dragon Ball Super introduced the Super Dragon Balls which are supposed to be the original set that created the Namekian Dragon Balls and they can grant any wish on top of being the size of planets.
    • From the same series is the Super Saiyan. Goku used to be the only one in existence. By the Buu saga, Vegeta's son Trunks and Goku's second son Goten could use the transformation before the age of ten without even being taught, and there were three different levels of transformation. The former was mercilessly lampshaded by Vegeta; the irony of it is that Vegeta himself caused the trend by also becoming a Super Saiyan. However, this only really holds true for a normal Super Saiyan as each level have fewer people having access to it. Super Saiyan 2 is only used by Goku, Vegeta, and Gohan, and Super Saiyan 3 is only gained by Goku and Gotenks. Only Goku ever becomes a Super Saiyan God and Super Saiyan God Super Saiyan is exclusive to Goku and Vegeta.
    • There's also the idea of Freeza as the most powerful being in the Universe. For a time the show found ways to Hand Wave the increasingly powerful foes Goku had to face after him. The Androids and Cell didn't exist yet when Freeza was alive. The warriors Goku faced in the afterlife a) were dead and thus not counted against Freeza's claim of strongest IN the Universe, and b) had been training for thousands of years. The claim gets a bit shakier in the Buu Saga. Majin Buu had been sealed for so long that it's likely Freeza was simply unaware of him, but many of Babidi's henchmen, Dabura especially, seem likely to have been at least as strong as Freeza (although we don't have confirmed power levels for them and in Dabura's case he comes from a parallel world in the shadows of Earth). With the introduction of Beerus, who is well-known enough for Vegeta to be terrified of him, Freeza's claim seems downright delusional. Resurrection 'F' addresses this by having Freeza privately admit that he was warned to absolutely never try to fight either Buu or Beerus by his father, so his claim of being the "strongest in the universe" was likely propaganda from the beginning.
    • The Kamehameha was originally introduced as the ultimate ki technique of Master Roshi, one of such complexity that it took him fifty years to perfect it. Goku does it on his first try, and it becomes his Signature Move. Later, though, Krillin and Yamcha are both able to perform it, not to mention Goku's own children.
  • In the first season of Code Geass the Hadron Cannon was an experimental weapon capable of destroying a small army, and only the Knightmare Frame Gawain had it; at the same time, it was one of only three Knightmares with the ability to fly. By the second season there had been a one year Time Skip, however, and suddenly a bunch of Knightmares had Hadron Cannons equipped, and by the end there were barely any Knightmares that couldn't fly. Takes a turn for the bizarre in the finale, when one of the Knightmares flying around is clearly a Portman (a dedicated Knightmare submarine).
  • JoJo's Bizarre Adventure: The Stand Bow and its Arrows allowed several Ordinary High School Students, prison inmates, the Mafia and many others to acquire Stands where they wouldn't have otherwise. The Arrows had the limitation of killing anyone without the spiritual strength necessary to control a Stand, but Josuke of part 4 got around this in one case by healing the dying Koichi after he was pricked by an Arrow.
  • Tengen Toppa Gurren Lagann: You stole a giant robot, making you the most dangerous humans on the planet? Good idea; now we've all done the same in imitation! What, now you've learned to combine them and wield superhuman power? We'll all start doing that too!
  • Digimon Adventure:
    • The 8 Chosen Children were the only people with Digivices and Digimon partners. It appears now that, in Digimon Adventure 02, there are hundreds, or maybe thousands of chosen children all over the world, each with a Digivice and a Digimon partner. Of course, in the end, everyone in the world has a Digimon partner.
    • In the franchise as a whole, a certain mon will be introduced as having developed under special circumstances. They'll be a regular part of the universe in other, unrelated series, though. For example, Armor Digivolving in Digimon Adventure 02 is an ancient method that the new Big Bad, Ken, can't shut down with his Control Spires because, well, a virus made to take out a computer using Windows 8 probably wouldn't work on a TRS-80. The only Armor Digimon are the armor forms of our heroes. Not so the later series, where Armors are everywhere. In Digimon Tamers, Guilmon was created from scratch by Takato. No others exist and his Digimon Analyzer sequence basically amounts to "huh? What do you mean, 'no data?'" Digimon Frontier has forms of Guilmon as Digimon elementary school students.
    • Also, Mons of the main ones' races are rare within their series but not outside of it. Unlike Armors or Guilmon, there's no in-universe reason why we don't see any other Gomamon in the series where one is a main character... but we don't. However, there's a whole tribe of them in Frontier.
    • Then there's Mega Digimon in general. In Adventure, the stage before Mega is considered fully evolved. Megas always happened through special circumstances; Venom Myotismon had a prophecy going for him (and having his bats eat the data of all his minions and infuse him with it helped.) Metal Etemon had fallen into and absorbed the entirety of the Dark Network, Saber Leomon had been exposed to a metric buttload of Digivice energy. Then there's the Big Bad quartet that's the Evil Counterpart of The Four Gods, the heroes' Digivice-induced Mega forms, and The Four Gods themselves. Your average joe will probably never be a Mega; Ultimate is fully evolved and Mega happens through either help or basically being a god. But outside the Adventure-verse, civilian Megas are quite common, and all the heroes getting to go Mega is expected.
  • In Mobile Suit Gundam 00, the show starts with only fivenote  GN Drives in the whole world; later on, three new Gundams pop-up with imperfect Drives, and later still each of the three global superpowers is handed 10 such Drives. After a four-year Time Skip, The Federation is mass-producing the imperfect Drives, while the heroes still have the five they started with and any support machines have to piggy-back off of them by using particle storage tanks. At the end of The Movie, we see that 50 years later, mankind will be able to produce the true GN Drives.
  • In the original Mobile Suit Gundam, the Gundam itself is suggested to be a unique unit. Sure, the mass-produced GM's are pretty much the same design, but they look different enough to keep the Gundam special. Side stories, OVA's, and video games have introduced as many as twenty other Gundams running around during the One Year War, though none of them achieve the same level of notoriety.
  • Bleach: The first Menos Grande that is introduced is described by Rukia as being a Hollow so powerful that only the Royal Guard can fight them. However, she admits at the time that she's never encountered one before and her knowledge comes from a school text book. It's eventually revealed that there are three levels to a Menos Grande, the lowest rank having been the first introduced. The top level Shinigami (captains, lieutenants and lower ranked officers who have been acknowledged in-universe as being as powerful as lieutenants) can fight Gillian and Adjuchas ranks easily enough, but the Vasto Lorde rank is so powerful, even a captain will struggle to win.
  • One Piece has the Nigh Invulnerable logia-type devil fruits. In the first half of the Grand Line ("Paradise") and any of the Blue Seas, a Logia user would be highly feared and dangerous, as they can turn into an element, such as fire or electricity, and allow physical attacks to pass through. In the second half of the Grand Line ("The New World"), Logia users have substantially shorter lifespans because many of them don't seem to get that everybody can hit you there thanks to haki, demonstrated when one such character gets curb-stomped by someone better prepared while explaining that to the Logia user. It's notable that of the strongest Logia users in the series (Smoker, Crocodile, the Admirals, Eneru), none of them rely entirely on their devil fruit. The New World also contains the first arc with a Logia user directly working for a Paramecia usernote , Paramecia widely considered a far weaker category elsewhere.
  • Pokémon:
    • In early seasons, Legendary Pokémon could not be truly caught and controlled by anyone and appeared only in important episodes and movies. They were also nearly invulnerable. Later seasons have Legendaries appear in Filler episodes and tamed by trainers, as well as having them frequently sent into battle and getting defeated like other Pokémon. There's the particular case of Mewtwo: In Pokémon: The First Movie, Mewtwo was established as being the only one of its kind due to being created through a very specific amount of genetic engineering and killing all his creators minutes after awakening, creating a No Plans, No Prototype, No Backup situation where no more could conceivably be made. Then Pokémon: Genesect and the Legend Awakened introduced a different Mewtwo, made by a group with seemingly no knowledge of the original's existence. Yet it looks identical to the original in almost every aspect bar voice. One must wonder if any fool can simply whip up an identical Mewtwo if they have some test tubes and Mew DNA without any kind of prior research to work off of.
    • In a similar vein, there's Pokémon who can use telepathy to talk. For the first few movies, it was restricted to powerful Psychic type Olympus Mons like Mewtwo and Lugia (as well as an illusionary Entei). As the films went on, however, telepathy became dime a dozen among Legendary Pokémon, even those that weren't Psychic. It eventually reached a head towards the end of the Diamond and Pearl movies and the entirety of the Best Wishes movies, which not only had a movie with no less than FIVE Pokémon with the ability, but also had a Zorua (who's neither a Psychic, nor even a legendary!) and five Genesect (who one would think would have electronically enhanced voices more than anything) display the ability. Hoopa even has the ability despite also having the more impressive ability of actually talking! In hindsight, Mewtwo talking in the first movie seems far less impressive...
  • In the early days of Yu-Gi-Oh!, the Blue-Eyes White Dragon (a 3000-ATK monster) was stated to be so rare and powerful that only four were ever printed, and one of them was destroyed so it couldn't be used against the wielder of the other three. By Duelist Kingdom, we see Chaos Soldier (equal in strength to Blue-Eyes) and Black Demons Dragon (slightly stronger), though both had specialized requirements and Blue-Eyes didn't. By Battle City, two Elite Mooks were using Masked Beast and Masked Beast Death Guardius, both of which were stronger, Haga had Perfectly Ultimate Great Moth, Yugi had Valkyrion, and so on. By the time Yu-Gi-Oh! GX rolled around, just about everybody had a card that was at least as strong as Blue-Eyes, often with some kind of special ability. Blue-Eyes itself remains unique, being the strongest Normal Monster, but it's hardly anything that would be banned from the game.
    • Extra Deck methods have also become increasingly more common. In the original manga, only a few characters (Yugi, Kaiba, Jounouchi, Pegasus, Marik, and Mei) used Fusion, and it was never their primary strategy. In Yu-Gi-Oh! GX, Fusion Summoning became a lot more common, and the primary strategy for some characters, but there were still plenty of people who didn't use it, several of whom were main characters. In Yu-Gi-Oh! 5D's, Synchro Summoning was used by every single main character and most of the important ones, but there were still a good number of characters, mostly one-off villains, who didn't use it. In Yu-Gi-Oh! ZEXAL, a grand total of four characters (three of whom were using the same deck and all of whom used Fusion anyway) didn't use Xyz Summoning, and everyone else and their dog (quite literally, in at least one case) used it as their primary strategy. Yu-Gi-Oh! ARC-V actually takes a step back by declaring Extra Deck methods to be quite rare, limiting it to characters connected to LDS or to the various other dimensions (which, granted, is most of the main characters again).
    • Speaking of Arc-V, it's actually a plot point that Reiji studies Pendulum cards (cards unique to only Yuya) so he can mass-produce them. The Battle Royale features Pendulum Cards that litter the entire city, and by the next arc, all the main characters (sans Yuzu, who was MIA at the time) received Pendulum Monsters.

    Comic Books 
  • Superman was supposed to be the last of his kind, and kryptonite, the radioactive fragments of a planet that blew up lightyears away that didn't burn up in our atmosphere, was a rare commodity almost nobody had heard of. Throughout the Silver Age, a veritable rainbow of different sorts of kryptonite showed up, as did first Supergirl, then other survivors of Krypton. After the post-Crisis on Infinite Earths reboot, Superman was once again the last Kryptonian and kryptonite one troublesome and very rare material. And then, after a few years, the other Kryptonians started showing up again, along with the wacky varieties of kryptonite. It has been joked by this point that the only Kryptonian to actually die was Jor-El. Also, while Superman was depowered substantially following Crisis on Infinite Earths, and that nerfing has largely stuck.
    J'onn: Everyone always seems to forget... I'M AS POWERFUL AS SUPERMAN!!!.
    • Miss Martian and other White Martians, as well, having identical powers to J'Onn.
    • Lobo is as invulnerable and strong as Superman, though lacking the flight (without his bike), heat vision & freeze breath.
    • Every Kryptonian and Daxamite is equal to him in power (and some even greater).
    • Alternate-Universe Kryptonians are often even more powerful than primary-universe Kryptonians:
      • Bizarro, the Earth-0 Superman (or a clone, depending on the continuity), is an exact copy of Superman, but with less control.
      • Superman-Prime and Earth-2 Superman have (our) Superman's Silver-Age Power Levels... Meaning they can move planets, take hydrogen bombs to the face, and calculate their speed by how many times faster than the speed of light they travel.
      • Ultraman, the Earth-3 Superman, is equal in power to the primary Superman, but not only gains a Power-Up from Kryptonite, he also completely lacks his moral compass, meaning he doesn't hold back at all.
    • Several New Gods like Darkseid and Orion.
    • DC's acquisitions of other companies caused those labels' Alternate Company Equivalent characters to cause even more dilution when they were folded into the main Universe:
      • Captain Marvel always was his equal in everything, lacking his weaknesses, and has access to magical lightning, which completely bypasses Kryptonians' Damage Reduction. Since the 1940's (when he was then published by Fawcett Comics), Captain Marvel has been the go-to heroic counter to Superman whenever there's been a major Let's You and Him Fight moment.
      • Mary Marvel, Captain Marvel's sister, is a counterpart for Supergirl, meaning she's just as powerful as both the Big Blue Boyscout and the Big Red Cheese (with a few different powers, since her powers derive from female figures, rather than male).
      • Black Adam, being an evil counterpart to Shazam, is even more of a threat to Superman (Same powers, looser morals).
      • Icon (originally from Milestone Comics), is a total match for Superman, so much so that in the Young Justice cartoon, they lampshade this by noting that Superman initially thought he was a Kryptonian (and wanted him to join the League purely for that reason).
      • Mr. Majestic, Maximum Man, and The High (originally from Wild Storm) are all equal in power & powersets to Superman. Mr. Majestic is notable for being an Anti-Hero version of Superman (while Maximum Man is more comparable to Shazam.
    • While Superman remains one of the strongest members of the Justice League of America, in the grand scheme of things, he ends up not only being un-unique, but barely in the middle of the Power Levels of beings in the DCU, so much so that he had to gain a new Kamehame Hadoken-like power in 2014 based on his laser vision just to stay unique.
  • In Daredevil, Matt Murdock's radar sense was original a super power, the freak result of the accident that blinded him. Later, Frank Miller introduced a mentor character and revealed that anyone could learn to "see" without their eyes the way that Matt does.
  • Green Lantern:
    • In the original run, the Green Lantern Ring was a big deal. Just having it made an Earthling one of the most powerful beings in-continuity. Then Continuity Drift happened, and there were hundreds of Green Lanterns, and calling the human who had one "The Green Lantern" seemed rather silly. Then, there were several humans who had one, at the same time, in direct conflict with the established distribution method. Then we found out that there were other Lantern Corps of various colors. Slowly, the Green Lantern Ring was necessary to be even marginally effective in related conflicts, and some characters who have them still can't hold their own.
    • Hal's joining the Green Lantern Corps is treated in some stories as ground-breaking, with him being the first human to join them... until the stories that ret-conned this so that Hal wasn't the first, with an American frontier-man named Waverly Sire having been inducted during the 1800s.
  • A common complaint about the Darker and Edgier treatment of previously lighthearted characters: Batman is cool, but that doesn't mean every character should be Batman.
  • The Hulk: Over the years, many other gamma-powered powerhouses have appeared to rival the Jade Giant, including She-Hulk, Doc Samson, The Abomination, Red Hulk, Red She-Hulk, A-Bomb, Skaar, Cosmic Hulk, and the Totally Awesome Hulk. You know, just to name a few. Worth noting, however, is that except for brief stints with The Worf Effect, the Hulk hasn't been unseated as World's Strongest Man by any of them, mostly due to his uniquely-unstable mentality, which gamma power feeds from.
  • The Mighty Thor: Since the introduction of Beta Ray Bill (back when it wasn't just impressive but downright shocking for somebody other than Thor to be "worthy"), many characters have been demonstrated to lift Mjolnir, with a few of them actually taking up the mantle of Thor for a time. The most established of these being Thunderstrike, followed by Jane Foster.
  • Spider-Man: Thanks to years of clones, alternate-reality versions, distaff counterparts, future children, and alternate-reality successors, the number of spider-themed characters has increased exponentially. Those still in publication by the year 2015 include: Spiderman 2099 (Miguel O'hara), Spider-Woman (Jessica Drew), Madame Web (Julia Carpenter), Scarlet Spider (Kaine), Spider-Girl/Woman (May Parker), Spider-girl (Aranya Corazon), Miles Morales, Silk (Cindy Moon), Spider-Gwen (Gwen Stacy), Spider-man India, Spiderman Noir, Superior Spiderman (Otto Octavius), Spider-man UK, and Spider-Ham (Peter Porker). And that's not including any symbiote, nor all the other spider-people we saw running around in Spider-Verse.
  • Like Superman and the Kryptonians, there was Archie Comics' Sonic the Hedgehog and the Echidna race. First, there was just Knuckles. Then, we're introduced to his uncle, the power-mad Enerjak and learn that Knux's father, Locke, was alive. Then, there's Athair, a former Guardian-turned-mystic Then, we're introduced to the Dark Legion right before Echidnaopolis reappears with an entire city of Echidnas. Then, we learn that Athair is leading an entire tribe of echidnas to a mystical city of Echidnas. Before the Time Skip, we had Echidnas coming out of the woodwork. The time skip culled them down and the Continuity Reboot reset it back to how it was.

     Fan Works 
  • Soul Eater: Troubled Souls: While this aspect is never seen as a big deal in the manga, the anime finale made it a point of interest that Maka is the child of a Meister and a Weapon. In this fic, several other characters with the same kind of parents are introduced note  . Likely because of that, the story goes the manga route and never brings it up.
  • In Tangled In Time Ganondorf is no longer the only male Gerudo; a Castle Town boy, Fyrus is also one, born from a Gerudo migrant and a Hylian barkeeper. Justified that it has been fifty years since the events of Twilight Princess, giving enough time for another male to be born.

    Film 
  • The Iron Man series includes a number of knock-off Iron Man suits, including Stane's giant version in the first film and Vanko's various suits in the second film. In the third film, Stark himself has a virtual army of his own Iron Man suits zipping around without his direct control.
  • The plot of Rio hinges on Blu being the last male blue Spix's Macaw. By the end of the movie, he has managed to mate with Jewel and produce three offspring, with Tiago being male. Then the sequel comes along, revealing that there is a lost flock of macaws hidden in the Amazon rainforest, with Jewel's father Eduardo among them.

    Literature 
  • Star Wars:
    • The rancor beast from Return of the Jedi was originally described in the novelization as a mysterious, possibly mutated creature: "The size of an elephant, it was somehow reptilian, somehow as unformed as a nightmare. Its huge screeching mouth was asymmetrical in its head, its fangs and claws set all out of proportion. It was clearly a mutant, and wild as all unreason." Nevertheless, due to rancors being awesome, they quickly proliferated through the Expanded Universe. Later the novel 1994 novel The Courtship of Princess Leia introduced the previously undiscovered planet of Dathomir, to which the rancors are native. And it turns out taht Jabba's rancor in Return of the Jedi was actually a small example of the species. Dathomir itself then propagated in the EU, to the point that the 2004 novel Ruins of Dantooine included Dathomirian beasts, a common biologist with detailed knowledge of Dathomir's ecosystem, and other characters who'd apparently been to the planet ... 8 in-universe years before the planet became known beyond a small circle of individuals.
    • Grand Admiral Thrawn was initially presented as a member of an unknown species, established after 8 years OOU and 10 IU timeline years as the heretofore reclusive Chiss species from the Unknown Regions. After this, of course, Chiss proliferated in the EU, most recently and egregiously in the novel Darth Bane: Path of Destruction a full 1000 years before the species was supposed to have been known to the galaxy at large. In Star Wars: The Old Republic, the Chiss are running around over 3,500 years before they're officially supposed to be known (although there was a galactic dark age shortly after this era so the records could have just been lost).
    • Obi-wan Kenobi and Yoda were intended to be the last surviving Jedi from the old Jedi Order, period. Of course, it didn't take long for the Expanded Universe authors to start creating their own survivors who went into hiding or were mysteriously overlooked. Not to mention the hundreds of Sith all over the place.
    • Force Lightning. At first, it was a very rare power only the most veteran and skilled Sith had, which was a testament of their power. In the EU, either be books, comics or (especially) videogames, every Sith (or just a darksider) can use Force Lightning, and thus becoming so common that it replaced the Force Choke as the signature ability of the Dark Side. Taken to a ridiculous degree in some works where Jedi can use it was well. Luke himself uses a variant of it in New Jedi Order that is instantly lethal. This could mean that Force Lightning is something that any sufficiently powerful Force-user could wield, but the Jedi generally refuse to because it's basically made only to cause extreme pain.
    • This is actually discussed about the Sith in the Darth Bane trilogy of books. Bane realizes that having more than two Sith Lords at any one time spreads the dark side of the Force too thinly, and the Sith as a whole are weakened because the Sith crave power to the point that they're willing to jeopardize their plans for galactic domination just to get a leg up on their rivals and thus leave the Sith vulnerable. Given how many times Sith empires had collapsed for precisely this reason, Bane clearly had a point. The line of reasoning behind the Rule of Two (that there should only be one master and one apprentice) is that there is one Sith to embody power, and a second to crave it.
  • Throughout the third Harry Potter book, Harry is told the difficulty of performing the Patronus Charm and it is implied only powerful/very skilled wizards can use the advanced spirit animal form. Yet many characters are shown with them, and by the end of the fifth book Harry has taught it to a bunch of his classmates. The power of the Patronus varied greatly between characters though.
  • Percy Jackson and the Olympians:
    • It is many times mentioned how few Greek half bloods there are, even before Luke starts recruiting them. Yet in the Heroes of Olympus series, a whole new Roman camp is revealed, with not only more demigods, but children of demigods, and children of children of demigods. Justified Trope, everyone who knew both camps all swore upon the river Styx to never speak of it and the Gods tried their hardest to keep them separated.
    • In The Lightning Thief, Percy being a son of Poseidon is a big deal, because Poseidon, Zeus, and Hades swore not to have anymore demigod children after World War II. While Zeus broke the pact first, his daughter Thalia is dead by the time the series begins... but she's brought back to life at the end of the second book, and the third book introduces Bianca and Nico di Angelo, two children of Hades that were born before the pact, but are still young because their father hid them in a time-warp. Bianca is promptly killed off, but the sequel series gives Thalia and Nico each a new sibling, bringing the total to five. Justified because the central plot of the story revolves around a prophecy concerning a child of Poseidon, Zeus, or Hades, and it would be really boring if Percy was automatically it. (He is it, but...)
    • At first, half bloods had to pray to their parent, or focus most of their energy to use powers like lightning bolts or huge waves. But by the final battle, Jason manages to summon a storm, and Leo enough fire, to defeat Gaia, without breaking a sweat.
  • In The Wheel of Time, Rand is the only character on the side of good who can Travel (create gateways to travel to other places instantly) during the fifth book. After he explains it to Egwene in the sixth book, she discovers the female version and teaches the Aes Sedai at Salidar. He also shows it to Mazrim Taim, who teaches the weave to the Asha'man.
  • Lifemating (the full-on Mindlink Mates type) is supposedly a rare thing to happen in the Liaden Universe, but roughly half the adult characters in Clan Korval have ended up with one by now.
  • Mentioned in Discworld: a mountain can thwart dozens of attempts by strong men to climb it, but once it's done little old ladies will take a stroll to the summit for tea, and then wander back afterwards to see where they'd left their glasses.
  • In Vampire Academy, Lissa and Rose are introduced as a rare spirit user and shadow-kissed pair. They have to figure out what they are and the nature of their powers through studying the lives of Medieval predecessors Saint Vladimir and Anna. As well as knowing an elder spirit user in teacher Sonya Karp. They are hinted to be the first spirit users in centuries. Later books introduce spirit users Adrian Ivashkov, Oksana, Avery Lazar, and Robert Doru. There are even some unnamed, insane spirit users incarcerated in Tarasov prison. Suddenly Lissa does not seem so unique anymore. And as for shadow-kissed characters there are Mark (Oksana's bondmate), Alden (Robert Doru's deceased bondmate) and Reed Lazar and Simon (Avery Lazar's bondmate). Making Rose less unique as well.

    Live Action TV 
  • The Borg's first appearance was on Star Trek: The Next Generation as a mysterious, frighteningly advanced and implacable species from beyond known space. Then Voyager has a whole arc in which one Starfleet ship has to fight and/or sneak into Borg space solo, and succeeds. This crosses over with a justified case of Menace Decay; Starfleet learned some painful lessons from their initial run-ins with the Borg and were a lot better prepared in subsequent encounters. These subsequent Borg encounters also reveal that all growth in Borg abilities comes from assimilating the technology of others and directly experiencing their tactics. Innovation is simply beyond their ability; the Borg are purely reactive.
    • This also happened with warp core breaches. Originally introduced in the episode "Contagion", it was stated as an extremely unlikely occurrence due to the numerous fail-safe systems designed specifically to keep it from happening. Then the show's writers realized that a "warp core breach" was synonymous with "imminent danger", and they started happening with a depressing regularity. Apparently, all those fail-safe systems suddenly became useless.
  • Doctor Who:
    • In the early years we knew almost nothing about The Doctor's people - it was six years before we learned the name "Time Lords". From the Tom Baker serial The Deadly Assassin onwards, we began to learn more and actually visited Gallifrey. Over the next decade or so, more stories featuring the corrupt, self-interested and machiavellian Time Lords were made, to the point where many fans complained that too much was being explained and the mystery had gone. One of the objectives of the so-called "Cartmel Masterplan" was to reintroduce the mystery regarding the Doctor himself by retconning much of what we knew about him to be a lie and implying that he was a much more powerful figure than a "mere" Time Lord.note .
    • The new series managed to bring this back a bit, by having them all supposedly killed off. This means that for modern fans, any slight suggestion that there might be another one out there is incredibly exciting. They've since come back, had their return thwarted, been saved, lost, found, lost again, and then eventually wandered back on their own as of the end of series 9.
  • Supernatural:
    • The introduction of the Devil's Trap at the end of Season One. Apparently Sam and Dean, two of the most experienced hunters out there, not to mention their father, didn't know about a magic chalk circle which could trap demons. As soon as Bobby uses it, suddenly everyone with even basic awareness of demons can make one, and it starts appearing everywhere as a primary security measure.
    • This also happened with demon-killing weapons. In the first couple seasons, the only thing known to be able to kill a demon was an enchanted Colt Revolver made by Samuel Colt under very special circumstances (it's mentioned that, among other things, it was crafted during the battle of the Alamo, and while Halley's Comet was overhead). It had only 13 bullets, 8 of which had already been used by the time the heroes got their hands on it, and once all the bullets were used the gun would be worthless. However, in season 3 the heroes figured out a way to make new bullets for the Colt, and also came into possession of a demon-killing knife. Then season 4 introduced angels, who can kill most demons just by touching them, as well as allowing Sam to kill them with his Psychic Powers. By season 8, it had been revealed the blades carried by angels could also kill demons, even when wielded by non-angelic beings. Cue just about every major character obtaining an angel blade offscreen. Then season 10 introduces the witch Rowena who invented the spell "Defigere Et Depurgare" that can easily liquefies demons.
  • Stargate Verse:
    • The Stargate is a wondrous piece of technology on which the fate of humanity rests when it is first found, only to become increasingly trivial as time goes on; by the end of SG-1, Earth had picked up a few dozen from uninhabited worlds to make a bridge between galaxies, then just left them there when the project fell through. They took one as a replacement when their gate blew up.
    • Stargate is full of this trope. Amazing and unique devices that wowed and shocked us three episodes ago are now commonplace. One of a kind cloaking devices? Now comes standard on every model. Fast hyperspace travel? Every little podunk space ship has got one. The list could go on. This is mostly justified in universe as Humans Are Special, or more specifically, the Tau'ri are special and every other culture is static, and that the whole point of the SG teams going out into the universe is to acquire tech, which sort of somehow ends up in the hands of everyone... This is good in the sense that Earth develops technologically over time, becoming something of a superpower, thereby avoiding the Reset Button plaguing many science fiction universes. On the other hand, it leads to massive power creep.
    • Stargate Universe has its own little odd twist: the Icarus base required the power of a planet with an ultra-super rare one of a kind naquadria core. One more was found by the Lucian Alliance, and it turned out that Jonas's homeworld was also a suitable candidate (understandably, they objected to a procedure that might blow up their planet). Mind you, naquadria, when first introduced, was explicitly an artificially-created variant of stable naquadah that only existed on Jonas's homeworld because the Goa'uld that invented it set up shop there. It is not supposed to be naturally occurring.
    • Ra was introduced in the movie as the Last of His Kind. Stargate SG-1 put the lie to this in the first episode.
  • Early on in Hercules: The Legendary Journeys and Xena: Warrior Princess, there was only one thing that could kill a god: the blood of the Golden Hind. By the time both series ended, there seemed to be a new way to kill a god every week. One of them was an axe to the back thrown by a mortal woman.
  • In Volume 3 of Heroes, there was a Bad Future where a Super Serum had been industrialized and everyone has superpowers... even the terrorists.
  • Buffy the Vampire Slayer:
    • "One girl in all the world, a Chosen One. She alone will wield the strength and skill to fight the vampires, demons, and the forces of darkness." Halfway through the second season a second slayer shows up; and then, in the finale, they cast a spell that allows thousands of girls across the world to become Slayers at once.
    • Angel being the vampire with a soul also becomes less unique when Spike gets his soul back too.
  • Once Upon a Time does this with the ability to travel between the worlds. In the pilot there're apparently only two ways to travel from the Enchanted Forest to the real world: the Dark Curse casted by the Evil Queen and the magic wardrobe made from a magical tree that allows Emma and Pinocchio to escape. Then halfway the first season we learn that Rumplelstilskin's son fell into a portal created with a magic bean and landed in the real world. This supposedly explains why Rumple has been planning to cast the Curse for decades manipulating everyone in the process but it brings the question why didn't he just seek for another magic bean?. Later the series introduces new more conveniantly means to travel between the realms: Jefferson's hat, Dorothy's silver slippers and a magic door. The white rabbit in the spin-off, the mermaids and the Author of the book also all have the ability to world cross at will making the situation even more riddiculous.
  • The Flash (2014) starts with just Barry having Super Speed. Pretty quickly, the Reverse-Flash is introduced (in fact, he's, technically, shown in the pilot, but we don't know it's him and only see a vague fast-moving outline). Then along comes Season 2, with Jay Garrick, the Flash from Earth-2, his nemesis Zoom, and Wally West. Then there's Trajectory, although she got her powers from the Velocity 9 serum.
    • There's also Gideon, the one-of-a-kind AI developed by Barry in the future and stolen by the Reverse-Flash. Then comes Legends of Tomorrow, and we find out that a Gideon-like AI (one of which is named Gideon but has a different voice) comes standard-issue on all Time Master ships. Even Chronos has one.
  • Agents of S.H.I.E.L.D.: Raina's Inhuman power is clairvoyance -She gets glimpses of the future. Several other Inhuman characters remark on what a unique power this is and that as far as they know, no other Inhuman has ever had it before. One season later, another Inhuman with the same power is introduced.

    Music 
  • Technical abilities displayed by musicians have gotten increasingly advanced in recent years, making formerly advanced musicians less impressive by comparison. The technical skills of Jimi Hendrix are within the expected reach of intermediate-advanced guitarists compared to modern guitarists like Tosin Abasi or Muhammed Suicmez. Similarly, previously high-speed drummers from a few decades ago are dwarfed by modern players, with extreme metal drummers like George Kolias or Jon Rice frequently utilizing eighths and sixteenths in excess of 240bpm.

    Mythology 
  • In Greek Mythology, Zeus tried to prevent this by keeping the secret of fire exclusive to the gods. Prometheus stole it and spread the gift of fire to the entire human race.

    Tabletop Games 
  • The Planeswalkers of Magic: The Gathering are one in a thousand in a thousand, spellcasters that can cross the expanses between planes. However, with their increased storyline focus comes an unspoken increase in their population; such that there are always enough planeswalkers on a given plane (at any given time) to round out a reasonably sized cast.
    Sarkhan: Planeswalker. That's what we're called. There are very few of us. But between you, me, and Ugin, there are three in this valley right now.

    Toys 
  • BIONICLE:
    • This appears frequently, often overlapping heavily with the Doing In the Wizard tendencies it develops near the storyline's end. Almost every detail has to have a subversive explanation behind it. As the writer described to the fans, tease all the plot threads you want, but you have to deliver the explanations sometime.
    • The original six Toa were introduced as borderline-mythical, ultra-powerful warriors. The Toa. When the Seventh Toa appeared, it was some truly major thing that heavily affected the plot. Then came the revelation at the beginning of the Metru Nui saga: "You are not the first Toa!" During that arc, one scene had a total of 300 Toa appearing at once. Since then, Toa have became as "standard" as the Jedi in their respective universe, and the original six had to be re-branded as Toa Mata.
    • Likewise, the Makuta, nowadays known as Teridax. The most mysterious and powerful, nearly untouchable evil might, the Master of Shadows and the ultimate foe the Toa have to face. Subversion: no, he's just one of the original 100 Makuta. Double Subversion: Makuta in general and Teridax in specific is still a tough bastard to beat, and what he lost in novelty, he makes up for with his schemes. But Makuta, as a species, are nothing special now.
    • Silver colored pieces. To a lesser degree, also gold. When the Toa upgraded into Toa Nuva, they received silver armor and weapons to reflect that they're "more" than mere Toa. The Bohrok-Kal came along, sporting silver as their secondary color to showcase their eliteness compared to regular Bohrok. After these, silver parts became a standard for absolutely every character, and colored weapons became such a rarity in fact, that when the 2009 first wave sets re-introduced element-specific colorings, there was much happiness... that lasted 'till the second wave, which went back to giving silver weapons to about half its sets.
      Gold went through an easier course. While beginning from 2004, many sets had it as their secondary or tertiary color, there were always figures (often special edition ones) that gave it some uniqueness. And in 2010, a former gold-wearing character had to be recolored silver just to make that year's "Golden Bionicle" promotion all the more special. But this didn't make all the other, non-special golden characters nonexistent.
  • In the My Little Pony: Equestria Girls movies, only ten characters have been shown to be able to "pony up" (i.e. gaining pony ears and wings). These include Twilight Sparkle, the human counterparts of the five remaining main characters, Sunset Shimmer, and the Dazzlings. The human counterpart of Twilight also may or may not have this ability. It's obvious why Twilight has the ability, the Humane Five and Sunset are implied to have spiritual connections to the Elements of Harmony, and the Dazzlings only gained the ability after absorbing and warping the magic of friendship. In the toyline, every doll is depicted with pony ears, and some are shown with wings (the one exception is the only boy doll, Flash Sentry). This includes characters not even based on ponies like Zecora and Queen Chrysalis.

    Video Games 
  • The Chaos Emeralds from Sonic the Hedgehog both invert the trope and play it straight. In the original game, their purpose was just to unlock the Golden Ending. From the second game onwards they became Plot Coupons that could be used as an unlimited source of energy and also unlocked the protagonist's Super Mode. In Sonic Rush, the Sol Emeralds are introduced, a second set found in another dimension.
    • Also, many of the cast had similar powers or statistics, but often at least some unique attribute. As time passed, more characters were created to mimic another's ability with only minor differences in controlling, so as to enable more counterparts for story mode and multiplayer. It is taken to the point that by Sonic Heroes, the characters are all categorised into "Speed", "Fly" or "Power" type abilities.
  • In Pokémon games:
    • Each generation is released with new legendary Pokemon, which are meant to be one-of-a-kind and incredibly rare. At last count, there are 52 of them, with fourteen of them being released in Gen IV alone.
    • This will also lead to a meta-example: Every single player knows where every legendary is, knows it's a Game Breaker, and (ab)uses it. So it's entirely possible to have a four-player Mewtwo and Mewtwo vs. Mewtwo and Mewtwo match.
    • With the introduction of Hidden Abilities in Gen V, many Abilities formerly exclusive to a single Pokémon or evolution line have spread to other species.
    • The same occurs with unique type combinations and signature moves. Dragon and Ghost types used to be represented by a single family each back in Pokémon Red and Blue. Now there's a good selection of them to choose from.
    • In its earliest appearances, Eevee was often mentioned to be a very rare Pokemon and was even implied to be extinct in the wild in Yellow. For a long time this trait was kept by the narrative, as the only Eevee the player could receive were gifts from NPCs or found after obtaining the National Dex in areas explicitly stated to contain rare Pokemon... then Generations V and VI quashed the entire notion by introducing areas that allowed the player to catch as many wild Eevee as they want. Despite this, its Pokedex entry in X, due to being reused from Diamond and Pearl, still pretends it's a rare species.
  • Kingdom Hearts introduced the Keyblade, a weapon that can open or close the heart of worlds, can open any lock, can't be stolen from the wielder, and can appear from Hammer Space. Only The Chosen One can wield it, but it turns out there were two chosen ones, and Riku giving into the darkness became a major dilemma since Sora had to fight his long-time best friend, who was better than he was. Then it turns out King Mickey is also a chosen one. Also Kairi. By the time of Birth By Sleep, it turns out there was once a whole slew of them, at once! Of course, it's explaimed that Keyblade wielders became a whole lot more unique because of a little something called Keyblade War, which ended in hundreds dead and what few that remained swearing to protect the worlds to keep it from happening again, as well as carefully training successors to not restart the Keyblade War.
  • For the first two Metroid Prime games, phazon is a rare and mysterious substance, and the space pirates go to great lengths to secure sources of it; but in Corruption, phazon is everywhere. It's reasonably justified in many cases in that phazon has been weaponized and thus heavily adopted by both the space pirates and the Galactic Federation as part of the interstellar arms race, and that phazon is found in the environments because the pirates are deliberately trying to spread it everywhere and it's pretty good at spreading itself anyway. However, it stretches disbelief a bit that every other random indigenous alien space monster now runs on phazon (according to the scan data), when they've only been exposed to it for a few weeks.
  • Warcraft has a few examples of this.
    • The night elves of World of Warcraft. In their introduction in Warcraft III they were ancient, immortal protectors of the world that had existed for 16,000 years at the bare minimum. Almost everything that defined their backstory, such as their immortality, how long they've been around, the betrayal of their leaders to the Legion, and the loss of their homeland, all would be matched or one-upped by the Draenei in Burning Crusade. As of Mists of Pandaria, it's easier to list the races that aren't at least as old as the night elves, with even the formerly-described "young race" of the humans revealed to have existed for 15,000 years (albeit not as immortals), and the draenei have for a whopping twenty-five thousand. The elves were also close allies of the dragons, but since Wrath of the Lich King the dragons have been popping up helping people everywhere.
    • The fact that night elves had glowing eyes were originally part of their magical, ancient and mysterious nature. Now a good third of the playable races have glowing eyes, and certain classes allow all races to have them.
    • When lore was first set down for the dragons, it was shown that all dragons belong to one of five "Flights": Red, Green, Blue, Bronze, and Black. World of Warcraft had the black dragons experimenting with creating a new, Chromatic flight, with powers of all flights. Even that idea proliferated quickly, with there being some sort of new dragons connected to the black dragons every time we met them, from Nether dragons to Twilight dragons. Then we met the proto-dragons, which were revealed to be the form of the dragons before they were empowered by the Titans, and ever since new kinds of dragons pop up all the time.
    • The Blue Dragon Aspect, Malygos, was said to have gone insane when his dragonflight was destroyed by Deathwing's betrayal during the War of the Ancients. This didn't prevent blue dragons from increasingly appearing in World of Warcraft, building up until Malygos formed an army to wage war on mortals as part of the insanity supposedly brought on by losing all of his kind. Similarly, in response to that betrayal, Deathwing's dragonflight was driven to near extinction. While they appeared occasionally as a common enemy, they started becoming more important and more subspecies of them continued to be introduced until they became a major villain group.
    • Warcraft III was about the Burning Legion trying to drain the power from the World Tree, which was treated as an apocalyptic event that required all the mortal races uniting to stop them. World of Warcraft introduced a new World Tree grown to replace the ruined one, but it was imperfect. Ever since, though, it seems like every new continent we stumble upon has its own World Tree or equivalent.
    • While Warcraft II expanded the world introduced in Warcraft I, it mostly elaborated on a continent that we obviously hadn't seen the entirety of. A major plot point of Warcraft III was the reveal of the lost continent of Kalimdor, and how the world used to be more like Pangaea until the Sundering. In World of Warcraft, the Mists of Pandaria expansion introduces a new lost continent with a plot that has a very similar outline, all the while acting like a mysterious hidden land is a unique concept.
    • Ogre magi were originally rare and powerful mutants created by the orc warlock Gul'dan. In Warlords of Draenor, it was retconned that ogre culture was defined by sorcerer-kings, who ruled their people with immensely powerful magic. While still rare by the standards of their people, the ogres were established to have been the dominant race of Draenor, making ogre magi a relatively normal thing.
  • Harry Potter might as well not appear in the Free Play part of "Lego Harry Potter Years 5-7":

    In Years 1-4, he had four rare or unique abilities: Expecto Patronem, perfect broomstick control, Invisibility Cloak, and Parseltongue. The first was an essential combat spell in some stages, and all four were used in a lot of puzzles.

    By the time Free Play is worth attempting in Years 5-7, any magical can use a broomstick perfectlynote , a lot of magicals have Expecto Patronem, and cauldrons with Invisibility Potion litter the placenote . Ron and Hermione have been gifted with one truly unique ability each, which are used in practically every stage, andnote  Ron now has the ability to crack any Parseltongue code, not just the one required by the plot. Harry just takes up space in your roster.
  • In Kirby's Dream Land 2, Dark Matter is thought to be a singular alien entity that tries to take over Dream Land. In Kirby's Dream Land 3, Dark Matter is actually just one of the larger entity of Dark Matter which goes and tries to conquer planets.
  • In Mass Effect 2, ardat-yakshi are described as so rare that, according to Samara, only three are known to exist in the galaxy, all three of whom are her daughters. She does mention her desire to track down others that might exist undocumented. Skip forward a few months to Mass Effect 3, and there's a colony where hundreds of them live in isolation, and bringing more to the site seems to be a routine task for Justicars. This is later clarified that the condition exists on a spectrum, and most of the ardat-yakshi at the colony only have varying degrees of potential for the problem to emerge: the three Samara mentioned are the only "true" ardat-yakshi, the only ones with a severe enough case of it that it manifests fully.
  • This is cited in Jade Empire for why Kang The Mad refuses to create any duplicates of his wonderful flying machines, though he certainly can do so. One Marvelous Dragonfly is a unique treasure, a magnificent work of technological art. Hundreds of them would make them cheap and commonplace. Of course, since Kang is actually Lord Lao, a minor deity of inventions and technology, he's not operating on the same thought process or morality as mortal humans
  • The Legend of Zelda: The Legend of Zelda: A Link Between Worlds does this with the Triforce. Turns out that Lorule had its own version of the Triforce, only upside-down. Granted, it was destroyed ages ago, but it gets brought back at the end of the game by a wish on the Hyrulean Triforce.
    • A retroactive example occurs with the Hylian Shield. In Ocarina of Time it was merely the standard Adult Shield but in Skyward Sword, which added a shield decay mechanic, the Hylian Shield is indestructible and is a divine gift that Link must go through trials to gain. Given that in Ocarina the shield is said to be the one that the castle guards use this may be a case of reverse engineering.
  • This was what hurt Star Wars: Galaxies. Jedi were meant to be super rare as the game was set after the original trilogy. They were meant to be the end result of a lengthy quest line that could even have false ends. Then, the creators decided to allow anyone to start off as a Jedi. That... went well as expected.
  • Interestingly, the currency of the Bayonetta series, Halos, are pretty much decayed immediately after their introduction. They are described a very rare, spiritual metal containing the Life Energy of angels and are even built up to be a big deal by weaponsmith and bartender, Rodin, only for them to become increasingly commonplace in the very first battle, enemies dropping them like Halo-filled Piñatas.
  • Halos make a return, still described as rare as ever, in Bayonetta 2, but they are joined by an equally described as rare new currency made from crystallized demon's blood called Orbs (which also serves as a Shout-Out to the Devil May Cry series), which become just as commonplace once Bayonetta starts defeating Infernal Demons on a regular basis.

    Webcomics 
  • Justified in Schlock Mercenary with the teraport. Kevyn invents the technology and before too long everyone has it, because they spammed half the galaxy with the specs to prevent the idea being suppressed. Also unusual in that the consequences of the sudden proliferation of this new technology are also explored.
  • Zigzagged in Darths & Droids with lightsabers, which everyone refers to as "laser swords". At first they're assumed to be some cheap, low-level trash that the protagonists apparently bought in a bar. Then Jim gets the idea to use them to deflect blaster attacks, which allows him and Ben to curbstomp a squad of droids they were supposed to have no chance against. This trope then gets inverted when it's said that only Jedi carry lightsabers, only to be played straight later when Darth Maul, a simple private detective in this universe is shown to be carrying one as well with no explanation.
  • Parodied in The Order of the Stick: upon being introduced to Zz'dtri (an obvious parody of Drizzt), the Order notes that dark elves are Always Chaotic Evil.
    Nale: Now the whole species consists of Chaotic Good rebels, yearning to throw off the reputation of their evil kin.
    Haley: Evil kin? Didn't you just say they were all Chaotic Good?
    Nale: Details.
  • In one Questionable Content arc, Hannelore gets a humanoid robot chassis prototype from her Mad Scientist father. Four years later (but less than 18 months in-universe), humanoid chassis are unremarkable.
  • Homestuck has the God Tier tranformation. When it's introduced, the recipient becomes the most powerful of all the main characters and it's implied that only an extremely small fraction of Sburb players manage to achieve it. Several hundred of strips later, there are no less than twelve regular characters at God Tier (with many managing to accomplish it despite the original process for becoming God Tier being impossible for them, only for that to be retconned), not counting all the doomed timeline background fodder.

    Western Animation 
  • In The Legend of Korra, some of the rare and unique variants of the four Elemental Powers of Avatar: The Last Airbender have become commonplace:
    • Lightningbending, which was emphasized as being dangerous and masterable by only a select few (all the ones in the original series were members of the royal family), has become common enough that people who need second jobs can do it to run a power plant (though Word of God states that lightningbenders are still relatively rare).
    • Similarly, metalbending (previously exclusive to the original series's Toph) is a standard skill taught to Republic City's police force, Zaofu's city guard, and the Earth Empire's Elite Mooks (though this is not an example of Continuity Drift, since Toph founded the first metalbending school and Republic City's police, her younger daughter founded Zaofu, and a former Zaofu guard founded the Earth Empire).
    • In the original show, one vengeful waterbender enslaved by the Fire Nation had discovered bloodbending, and she taught it only to Katara, who finds it so abhorrent that she uses it on extremely rare occasion and would definitely never teach it to anyone else (in fact, she eventually gets it outlawed). The control it requires is such that even for a master waterbender, it was thought to be possible only under a full moon, when a waterbender's power is at its peak. In The Legend of Korra, Tarrlok, his brother Amon, and their father Yakone are all revealed to be bloodbenders, each powerful enough to immobilize a full room of people without a full moon. Sokka even lampshades this in a flashback to Yakone's trial, noting that even during his youth, people were developing bending in ways previously thought impossible.
    • Permanently removing a person's bending abilities, introduced in the final episode of the first series as an ancient ability that had been lost to time, was a maneuver thought only possible by the Avatar in the Avatar State to boot, at great risk to himself. Amon, the Big Bad of the first season, is able to effortlessly debend someone, although the means that he does so are revealed to be completely different from Aang's.
    • Though it's unknown whether chi-blocking was completely unique to Ty Lee, the Equalists use her Pressure Point-based techniques to fight against benders, though in her case it's mentioned that she did teach it to some others.
    • Combustion Man's explosion-based combustionbending is still quite rare in Korra's time, allowing P'Li to remain a serious threat in Book 3, but the particulars of how it is performed are now well-known, as are its weaknesses.
    • In Avatar: The Last Airbender, Airbending was almost completely wiped out, with one sole survivor. Come the Sequel Series, there were four, all descendants of the last survivor. Korra manages to get some by the first season finale, but all airbenders we see aside from this small group of people are from the past. Then season 3 comes around, and now hundreds of airbenders are running around thanks to Harmonic Convergence.
  • The status of alicorns in My Little Pony: Friendship Is Magic seems to be gradually slipping into this. When they were first introduced, there were only two of them, Princess Celestia and her sister, Princess Luna. While they had the title of "Princess", the show treated them more as divine royality or Physical Goddesses. Halfway through season 2, we see a picture of an unnamed Winged Unicorn princess in a book (though this may not be canon, as different camera cuts of the very same page show her as an earth pony). At the end of season 2, Princess Cadence was introduced. She was originally conceived as a unicorn, but was made an alicorn due to Executive Meddling. By the end of season 3, Twilight Sparkle, the main protagonist, was also made into an alicorn. Season 4 finale firmly etablishes that there are only four known alicorns in Equestria. In season 5, Princess Cadance and Shining Armor have a baby named Princess Flurry Heart, who is also an alicorn princess, bringing the total to 5. And the toy line has two more who don't appear in the show (Princess Gold Lily and Princess Sterling).

    Real Life 
  • A popular saying runs, "God made man, but Sam Colt made men equal." Prior to the revolver, handguns were expensive, inefficient, and inaccurate, but Colt managed to develop the relatively inexpensive revolver. The result was personal firearms becoming much more common.
  • Nuclear armaments fit into this. During WWII, only a few countries were trying to split the atom. After the atomic bombings of Hiroshima and Nagasaki, and the capability of nuclear weaponry became realized, more and more nations scrambled to get their own nukes ready. Now, there are five nations that openly are accepted to have nuclear weaponsnote , three nations that not-so-secretly have themnote , two more that are making strides to get themnote  and one that might have been attempting to start a weapons program in the recent pastnote . And all that's not even getting into the dozens of nations that theoretically could get them at any time if they were willing to put up with the international pressure that would be put on them and the various nations that did have nuclear weapons or a weapons program at some point in the past. Combine that with the constantly decreasing difficulty of building more powerful missiles means that more than a few could have weapons capable of vaporizing cities and those weapons could be fired at targets thousands of kilometers away. Unsurprisingly this means that a lot of nations get very uneasy whenever two or more nuclear-armed nations get into a standoff.
  • Really this applies to nearly any technology that people want. Computers, weapons, cars, cell phones... as the cost of making something decreases and the knowledge of the makers increase every technology eventually will lose its rare availability.
    • This applies to knowledge as well. Literacy was a rarity until recently, and the fact that you're probably not reading this text aloud makes you more literate than anyone a thousand years ago. Know how to do long division? You'd be a wizard in 15th-Century Europe, since Arabic numerals hadn't been introduced yet and division was practically impossible with Roman numerals. You might even know enough about relativity to prove Newton wrong, even though it was barely in universities one hundred years ago.
  • The color purple. Once used as a color for royalty, now a color for just about everyone thanks to cheaper synthetic dyes.
  • Aluminum used to be worth more than gold. Refining its ores used to be very difficult, making pure aluminum very rare. The Hall-Héroult process made obtaining pure aluminum much easier and its high price subsequently collapsed.
  • When being a person who enjoys a certain thing stops being rare, It's Popular, Now It Sucks is born.
  • A story that is often told regarding the strength of the human spirit; before Roger Bannister broke the 4-minute mile, it was believed to be so impossible anybody who attempted would die in the process. After he proved it was possible, within a short time, high-school kids were doing it.
  • The United States and France were unique as republics in the 18th Century, but now most kingdoms left are constitutional monarchies with the king or queen as a figurehead, and even they're comparatively rare. France's form of nationalism, where membership of a country was based on a shared cultural identity rather obeying a king, was also unique for the time, but now every country (monarchies included) has some form of national identity separate from its rulers.
  • Zoroastrianism was the first monotheistic faith; now, a majority of the world believe in a single god, while Zoroastrianism itself isn't even in the top five forms of monotheism.note 

Alternative Title(s): Everyone Has A Power Ring, Novelty Decay

http://tvtropes.org/pmwiki/pmwiki.php/Main/UniquenessDecay