History ApocalypseHow / Class3a

* In ''Fanfic/TheJadedEyesSeries'' Harry/Tristan kills off all the muggles but for [[CruelMercy a few he leaves alive to be used as slaves or blood banks for his Creature allies.]]

* Three times in ''FanFic/TalesOfTheEmperasque'' -- the Emperor once cleanses a daemon world with his BreathWeapon and once causes continental shift from the orbit. The third time, it's the Imperial Navy that drops a cyclonic torpedo on an Orc-infested world.
* ''Fanfic/RWBYReckoning'' has the titular event. From what has been established, someone seeks a SoulJar, and wishes to use it to grant the [[AlwaysChaoticEvil Creatures of Grimm]] with souls. From there, the now intelligent monsters will ravage Remnant until no life is left. And it's not just Remnant: apparently, they plan to unleash the soul-charged Grimm onto Earth soon after...
* In ''Fanfic/{{A New World|IcedFairy}}'', the remnant of Lunarian society is so scared of human expansion on the False Moon, they see fit to seize control of Earth's nuclear arsenals and trigger a colossal war. [[spoiler:[[AllForNothing It turns out to be worse than useless]], as it was ''[[BatmanGambit exactly]]'' what [[ManipulativeBastard Yukari]] wanted them to do. Earth ''does'' suffer greatly... but the Lunarians are left extinct and their worst nightmare, the complete fusion of the worlds of magic and science, is brought into reality by humans and the magic races.]]

* The backstory of the ''VideoGame/LittleTailBronx'' series is that [[spoiler:the human race used {{Mechanical Abomination}}s known as Titano-Machina to wage WorldWarIII. Juno, the information system that the Titano-Machina were created from, determined that the massive destruction would lead to a ApocalypseHow/Class6 situation, and so proposed to a select few human researchers the "Reset" command, which would erase all of humanity so that the Earth's biosphere could be rebuilt. The researchers [[GodzillaThreshold accepted and initiated the command]], resulting in mankind's immediate extinction.]] It can be however argued that this example crosses over with a very temporary ApocalypseHow/Class6 as [[spoiler:Juno converted all other life-forms into data, and used them to re-seed the planet with new life, including the [[BeastMan Caninu and Felineko]].]]

*** When Buu unleashes a BeamSpam of epic proportions from the Lookout and kills every human not on the Lookout, [[ForTheEvulz just because he could]]. He later went and killed the few remaining people that were ''on'' the Lookout by turning them into food and eating them.

* In Creator/StephenKing's ''Literature/{{It}}'', this is what Patrick Hockstetter ''thinks'' will happen if he dies, since he believes himself to be the only ''actual'' (real) being.
--> He was a sociopath, and perhaps, by that hot July in 1958, he had become a full-fledged psychopath. He could not remember a time when he had believed that other people -– any other living creatures, for that matter -– were “real.” He believed himself to be an actual creature, probably the only one in the universe, but was by no means convinced that his actuality made him “real”....He didn’t want to die; as the only “real” person, he wasn’t ''supposed'' to die. If he did, everyone else in the world would die with him.

* In Creator/TomClancy's novel ''Literature/RainbowSix'', the environmentalist extremists plan this with an engineered disease to wipe the planet clean of all humans except for their own community.

* In Creator/OctaviaButler's ''Literature/{{Xenogenesis}}'' trilogy, the last few human survivors of a nuclear war are rescued by aliens; but, although they'll be returned to a fixed-up Earth, [[spoiler:they won't be human any more. And once the bioships are fully grown and leave the planet, it will cause a Class 5 or possibly even Class 6 Apocalypse]].

* ''VideoGame/{{Nier}}'' takes place in a world where humanity is slowly dying out. [[spoiler:In more ways than one, as it turns out: the "humans" you see throughout the game are "Replicants", artificial humanoids that were created as vessels for the souls of the real humans, known as "Gestalts", to protect them until the plague of White Chlroination Syndrome (a plague caused by the Red Dragon's death in Ending E of ''VideoGame/{{Drakengard}}'') could be cured. Something went wrong, however: the Gestalts were unable to enter the Replicant bodies, eventually mutating into Shades, while the Replicants became independent and started to fighting and killing the Shades, mistaking them for mindless monsters. By the end of the game, the project has completely fallen apart [[NiceJobBreakingItHero thanks to the protagonist's single-minded quest to save his sister (or daughter)]]. With Replicants being incapable of reproducing, even they will eventually die out, with ''VideoGame/NierAutomata'' beginning thousands of years after the Replicants' extinction.]]

* ''VideoGame/Nier'' takes place in a world where humanity is slowly dying out. [[spoiler:In more ways than one, as it turns out: the "humans" you see throughout the game are "Replicants", artificial humanoids that were created as vessels for the souls of the real humans, known as "Gestalts", to protect them until the plague of White Chlroination Syndrome (a plague caused by the Red Dragon's death in Ending E of ''VideoGame/{{Drakengard}}'') could be cured. Something went wrong, however: the Gestalts were unable to enter the Replicant bodies, eventually mutating into Shades, while the Replicants became independent and started to fighting and killing the Shades, mistaking them for mindless monsters. By the end of the game, the project has completely fallen apart [[NiceJobBreakingItHero thanks to the protagonist's single-minded quest to save his sister (or daughter)]]. With Replicants being incapable of reproducing, even they will eventually die out, with ''VideoGame/NierAutomata'' beginning thousands of years after the Replicants' extinction.]]

* The 1998 made-for-television film ''Film/WorldWarIII'' depicts [[AlternateHistory what might have happened]] if UsefulNotes/MikhailGorbachev, instead of bringing about the collapse of the USSR with his reform policies, had been deposed in a coup and replaced by a communist hard-liner, causing the UsefulNotes/ColdWar to escalate into a full-blown conflict. The film concludes with the two sides [[MutuallyAssuredDestruction firing their entire nuclear arsenal at each other, in the process destroying all traces of human civilization]], as indicated by the WhamLine, [[ThatWasTheLastEntry "There is no further historical record of what happens next."]]

* Music/{{Buckethead}}' s album ''Population Override'' manages to portray this scenario ... without saying a word! The whole album is instrumental.

* Towards the end of the 54-book ''Literature/{{Animorphs}}'' series, the Andalite military thinks that the only way to stop the Yeerk invasion of Earth is to release a quantum virus that will kill all humans on the planet.

* The ultimate goal of the Dragons of Earth in ''Manga/{{X1999}}''.

* In Archie Comics Sonic the Hedgehog Issue #124, it is originally revealed that Mobius is actually Earth, approximately 10,000+ years after an alien invasion had ended all life (human and non-human)on Earth, except for several pockets of humanity that survived in hidden cities, something that is expanded upon in the Sonic the Hedgehog Official Comic Encyclopedia (which covers all pre-Super Genesis Wave Sonic information and material).

* In ''Film/TheLastWitchHunter'', this is the BigBad's endgame -- to bring about total destruction of human race and civilization so that the witches can thrive.

* Though it wasn't his intention, Vandal Savage did this in the ''WesternAnimation/JusticeLeague'' episode "Hereafter (Part II)." Being immortal, he ends up very lonely.

** [[Recap/DoctorWhoS27E3TheUnquietDead "The Unquiet Dead"]]: The gaseous Gelth plan to kill all humans, and inhabit their corpses.

** [[Recap/DoctorWhoS27E13ThePartingOfTheWays "The Parting of the Ways"]]: The Daleks are back, and their plan is pretty much this. The Doctor's solution to save humanity? Kill at least ALL intelligent life on or near Earth, Dalek and human (granted, he didn't have time to actually remove the "and human" bit from the weapon). And he squicked at holding a ''gun'' on a guy. The Daleks ''talk him out of doing this'' because it'd give him ANOTHER genocide on his record, even though he points out there are humans elsewhere who would survive this. By the end of the episode the Daleks seem to have enacted this on Earth.

** [[Recap/DoctorWhoS30E17E18TheEndOfTime "The End of Time"]]: All of humanity except for two people is transformed [[MesACrowd into]] the [[{{Pun}} "Master Race"]], resulting in billions of duplicates of {{the Master}}. Fortunately, this is eventually reversed by another villain.
** In [[Recap/DoctorWhoS31E4TheTimeOfAngels "The Time of Angels"]], Alfava Metraxis suffered mysterious Dominant Species Extinction 400 years before the 51st century time setting. The Doctor theorizes the Weeping Angels, an entire army of whom are living in the extinct species' catacombs, caused it.

* In ''Series/{{Lost}}'', [[spoiler:if the Man in Black manages to escape the Island after being stuck there for two millennia, he plans to wipe out all human life.]]
* In the 2000 two part episode of ''Series/TheOuterLimits1995'' "Final Appeal" it's revealed that all episodes are alternate timelines and futures and that while many of them actually are tied together into semi coherence. the episode ends with a time traveler with a grudge detonating a fusion bomb taking out most of the eastern seaboard, rendering their arguing about this timeline's rejection of tech stronger than a light bulb pretty much moot.
* In ''Series/{{Primeval}}'' the not too distant future appears to be populated entirely by giant mutant bat things that we unleashed upon ourselves. The series is non-specific if this has wiped out humanity entirely in a full Class 3, or just mostly, but given the ferocity of the future predators and the abandoned state of cities it is at least a 2. The BigBad does state we've wiped ourselves out, but we're not about to take a villain's word for it just yet and the series does fall on the idealistic side of the [[SlidingScaleOfIdealismVersusCynicism Sliding Scale]] so there may yet be hope. Given the geologic time-scales with which this series usually plays around, the Future Predators may not have originally played any direct role in humanity's downfall. It's just as plausible that they evolved naturally, long after we'd gone extinct, and that they would never have met humans if the Anomalies hadn't brought some into the present.
* In ''Series/StarTrekVoyager'', the Krenim had developed a weapon to delete people from history. Any offworld colonies they would have made [[CosmicRetcon would be retroactively removed]] from history. Addendum: If these civilizations had {{Terraform}}ed any uninhabitable worlds, those would become Class 5 as the habitable world would never have been made habitable in the first place (at least by the people who made them so in the original timeline). It might fit Class X-2 more, because it shows that it's able to erase inorganic objects as well (Chakotay's talk with Annorax regarding simulation of erasing a comet), but the main show of the weapon is to specifically delete races, but left the planet intact for the Krenim to get it in the new timeline.

* WesternAnimation/TheOwlHouse: Phillip "Belos" Wittebane originally intended the "Day of Unity" to result in this as he wanted to use [[Recap/TheOwlHouseS2E16HollowMind a draining spell to kill off the witch population.]] [[Recap/TheOwlHouseS2E21KingsTide However, thanks to Luz and her friends]], this ultimately resulted in a [[Recap/TheOwlHouseS3E2ForTheFuture class 2.]]

* ''Webcomic/{{Klunscomic}}'': Planet B, B.B and Miss B's home planet, was destroyed in a Class 3a. [[spoiler:The B species created three children that would help them with their tasks. The first child, Miss B, didn't follow orders. The second, B.B, was a BlankSlate. The third brought about the end of Planet B, consuming every B in its path. If B.B and Miss B were to reunite with the third child, it would lead to a Class Z, with reality ceasing to exist.]]

Planetary-scale extinction of the dominant species on a planet, via unnatural causes (ie: someone did something, [[HoistByHisOwnPetard human]] or [[AliensAreBastards otherwise]]).

* Part of the backstory in ''Manga/AttackOnTitan''. A little over a century prior, strange beings known as Titans appeared out of nowhere and began to devour any humans they could find. The survivors have spent the last century living within three 50-meter Walls, with all information about the Outside World banned and mention that mixed-race heroine Mikasa is the last surviving Asian suggest extinction of multiple ethnic groups. The surviving population numbers in the hundred-thousands, and is under constant threat of extinction from either Titans (if the Walls are broken again), starvation from famine and food shortages, or even civil war due to the corrupt and oppressive government. The series begins with 20% of the population being wiped out when the first of the three Walls is lost. [[spoiler:However, almost everything just mentioned is later revealed to be a complete lie; while the island the main cast lives on ''is'' overrun with Titans, the rest of the world is filled with thriving human civilizations. In fact, the Titans themselves turn out to be just tools of the most powerful human nation, which just so happens to be a SuspiciouslySimilarSubstitute for Nazi Germany.]]
* ''Anime/CowboyBebop'', in which the Gate Disaster takes out half the moon and makes Earth uninhabitable for all but the hardiest of humans. It should, however, be noted that the rest of the {{terraform}}ed planets and moons in the system are okay; Earth is still in contact with the greater solar community, but is regarded as a backwater. This makes this Class 3 ''in theory'', but it's really more a large-scale Class 0.

** The Tuffle race in ''Anime/DragonBallZ'' is wiped out by the Saiyans who become giant apes at the full moon. They work under Frieza's planet trade to do this as a career choice.
** Also done in ''Z'' when Buu unleashes a BeamSpam of epic proportions from the Lookout and kills every human '''NOT''' on the Lookout, [[ForTheEvulz just because he could]]. He later went and killed the few remaining people that were ''on'' the Lookout by turning them into food and eating them.
** In ''Anime/DragonBallSuper'', [[spoiler:Goku Black hunts down and kills off 99 percent of humanity in Future Trunks's timeline.]]
* The main premise of ''Manga/DrStone'' involves every human in the world being turned to stone, and finding out the cause of this is part of the major MythArc of the series.

* If [[http://www.scp-wiki.net/scp-1101 SCP-1101]] of the ''Wiki/SCPFoundation'' breaks containment, it's possible that humanity will go extinct as every single human on the planet neglects basic bodily needs in favor of debating a particular subject, like whether or not tomatoes are a fruit or vegetable.