History TheEndOfTheWorldAsWeKnowIt / SCPFoundation

** ''SK-Class Dominance Shift scenario'': The dominant species being made extinct or forced into subjugation by another species. This could happen [[https://scp-wiki.wikidot.com/scp-752 if a currently contained species became aware of, then began direct competition with]] humanity; when [[https://scp-wiki.wikidot.com/scp-1157 a replicating human]] is unable to be contained and it takes over the planet, or [[spoiler: [[https://scp-wiki.wikidot.com/scp-1000 when humanity rose up against a dominant sapient species during our pre-history and took control over the planet.]]]].
** ''TK-Class Causal Restructuring Event'': The world or part of it is changed to a state similar to an earlier era. Described in the article for [[https://scp-wiki.wikidot.com/scp-1297 SCP-1297]], a jar of human toenail clippings that rolls history back by up to a century per nail clipping removed from it. [[spoiler: An addendum to the article implies this has ''already happened'' -- there is one clipping missing.]]

** ''YK-Class Entropic Annihilation Event'': Causing the entire universe to reverse its flow of entropy, effectively turning time backwards. [[spoiler: [[https://scp-wiki.wikidot.com/scp-2700 SCP-2700]], [[UsefulNotes/NikolaTesla Tesla’s]] DeathRay, contains a bundle of anomalously contained particles that behave against normal entropy as its core. Should the death ray fire, the particles would be released and the entire universe will be converted to reverse entropy.]] A YK event [[spoiler:happens every two weeks inside [[https://scp-wiki.wikidot.com/scp-2123 SCP-2123]].]]
** ''ZK-Class Reality Failure Event'': Reality as we know it is destroyed, and may or may not apply to multiple other realities. One of [[https://scp-wiki.wikidot.com/sandrewswann-s-proposal SCP-001's proposals]] mentions a non-zero possibility of a [[ApocalypseHow/ClassZ total metaphysical annihilation of the universe]]. [[spoiler: [[TheFourthWallWillNotProtectYou Because they are the authors of the universe.]]]]

* [[https://scp-wiki.wikidot.com/scp-3799 SCP-3799]] is a type of snow that expands by dissolving human corpses. Kinda creepy. Then it turns out that it has a memetic effect that makes people view the snow in religious awe and willingly go to die of hypothermia to become fuel. It eventually consumes more than ''40% of the planet''. And even worse, the memetic effect becomes worse over time, either affecting human memory and records, or outright rewriting history in its quest to [[spoiler: make everything pure and uniform]]. By the end, the Foundation has been rewritten into the SCF, Snow Containment Foundation, whose main goal is to contain the snow. [[spoiler:And they fail. Ultimately, only a few humans remain, completely convinced that the world has always been covered in snow, and that humans have always lived inside the foundation sites. The snow is finally stopped by someone performing a HeroicSacrifice, after somehow overcoming the memetic effect.]]

** ''#&9791;K-Class "World of Babel" Global-Incomprehension Scenario'': All of humanity is infected by SCP-3432 after it advances from its original form to a MindVirus that [[TheSpeechless causes progressive, total, and irreversible loss of the ability to communicate]]. Everyone ends up locked in their own heads, still able to think but unable to put together or understand any form of communication; anything that can transmit concrete information (spoken, written, or signed language, interpretive dancing, pictograms, etc.) is now impossible.

** ''ΩK "End of Death" Scenario'': Death no longer happens to any and all living beings and they all become TheAgeless and gain ResurrectiveImmortality, complete with drawbacks such as AgeWithoutYouth, CameBackWrong, and feelings of WhoWantsToLiveForever Society is irreversibly changed but adapts accordingly and tries to find workarounds to the drawbacks mentioned.

** ''MK-class Total Loss of Human Consciousness scenario'': All of humanity loses most of their higher-order thinking. The nature of the scenario is used multiple times but was not given a name until the [[https://scp-wiki.wikidot.com/scp-3002 SCP-3002]] was created, where a sapient idea destroys most of the Foundation, infects nearly all of humanity and all information in the world, and forces the Overseer Council to kill 11 of their members. [[spoiler:Because [[ComicBook/VForVendetta ideas are bulletproof]], the story ends on a cliffhanger with two possible outcomes: either Veles, O5-1, [[ResetButton resets the world]], or the idea hijacks all of the population and cuts off their free will. [[DespairEventHorizon The latter is more likely to some extent.]]]] Also, it should be noted the ending doesn't say if the O-5 council was eliminating infected members... Or, the other way around. [[spoiler:Also, [[https://scp-wiki.wikidot.com/scp-3733 SCP-3733]] is implied to take place in a post-MK world.]]

* [[https://scp-wiki.wikidot.com/scp-5000 SCP-5000]] invokes this scenario, mostly consisted of archives and data from a high tech suit that functions as a PerceptionFilter. Its deceased occupant is a survivor from an alternate universe, and filled the suit's databanks with an ApocalypticLog detailing how the SCP Foundation [[FaceHeelTurn suddenly reversed their creed]] of "We die in the dark so that others can live in the light" and launched a campaign to [[KillAllHumans exterminate the human race]]. The main motivation of carrying out an all-out war against humanity isn't clearly stated, naturally, [[LampshadeHanging as noted by the SCP-5000 user being annoyed at the pretentious usage of redactions in their protocols and instructions used to carry out the assault]]. The user details how dozens of [=SCPs=] such as SCP-096 and SCP-1048 are being weaponized against humanity and various [=GOIs=] like the Church of Broken God and Global Occult Coalition, while any [=SCPs=] that were fundamentally human or had human sympathies were destroyed. By the end of the logs, [[ApocalypseHow the whole world is now inherited by the newly-freed SCPs]], and the Foundation's forces have been replaced by mutated troops given the attributes of SCP-173. [[spoiler:If one does some digging through this article, the Foundation's reason for killing the human race appears to be the discovery that all known human emotions and senses, both good and bad, are the doing of a mind-controlling EldritchAbomination that essentially hijacked the human subconsciousness eons ago for motives left unknown - and the Foundation is so desperate to defeat this thing that exterminating mankind was deemed the ''[[MercyKill more ethical]]'' alternative. Thankfully (or unfortunately depending on what exactly the entity has in store for us), SCP-5000's user, one of the last uncorrupted Foundation personnel, managed to create a RealityBreakingParadox that [[ResetButton restored the world to an earlier point]]. But since that universe was reset to ''just'' before the discovery of the entity, there's no way to tell whether or not it will happen again.]]

* [[https://scp-wiki.wikidot.com/scp-5000 SCP-5000]] invokes this scenario, mostly consisted of archives and data from the suit which can be used as a PerceptionFilter. A survivor from an alternate universe created an ApocalypticLog from said suit which apparently detailed that the SCP Foundation [[FaceHeelTurn reversed their policy]] of "We die in the dark so that others can live in the light", and instead creates a new objective, [[KillAllHumans the extermination of the human race]]. The main motivation of carrying out an all-out war against humanity isn't clearly stated, though, [[LampshadeHanging as noted by the SCP-5000 user being annoyed at the pretentious usage of redactions in their protocols and instructions used to carry out the assault]], but the user details how several well-known [=SCPs=] such as SCP-096 and SCP-1048 are being used against humanity and how several [=GOIs=] like Church of Broken God and Global Occult Coalition are being decimated left and right. By the end of the logs, [[ApocalypseHow the whole world is now inherited by the newly-freed SCPs]] and [[HumanoidAbomination mutated MTF soldiers]] with praying-mantis like attributes. [[spoiler: If one does some digging through this article, the Foundation's reason for killing the human race is due to the fact that all known human emotions, both good and bad, were ''actually added in'' by a mind-controlling EldritchAbomination [[MindRape that essentially invaded the human subconscious eons ago]] for motives left unknown - and they're so desperate to defeat this thing that to them, exterminating mankind is the ''[[MercyKill more ethical]]'' alternative to allowing the being to go forward with whatever plan it might have in store. Thankfully (or unfortunately depending on what exactly the Entity has in store for us), one of the last uncorrupted Foundation personnel manages to create a RealityBreakingParadox that acts as a ResetButton that restores the world. But since that universe was reset to ''just'' before the discovery of the entity, there's no way to tell whether or not it will happen again.]]

** ''ZK-Class Reality Failure Event'': Reality as we know it is destroyed, and may or may not apply to multiple other realities. One of [[https://scp-wiki.wikidot.com/sandrewswann-s-proposal SCP-001's proposals]] mentions a non-zero possibility of a [[ApocalypseHow total metaphysical annihilation of the universe]]. [[spoiler: [[TheFourthWallWillNotProtectYou Because they are the authors of the universe.]]]]

* A distressingly large number of [[Wiki/SCPFoundation SCP]] objects can cause (or ''have'' caused) TheEndOfTheWorldAsWeKnowIt, to the point where the Foundation is actively predicting and categorizing the different ways the world can end, using the (fictional) "K-Class" classification system. [[note]]Remember that there is [[UnreliableCanon no canon]]. This list is purely for providing general examples and descriptions of explicitly identified scenarios. For more comprehensive lists (of equally dubious reliability), please refer to [[https://scpsandbox2.wikidot.com/k-class-scenarios this]] link and [[https://scp-wiki.wikidot.com/forum/t-225525/k-class-scenarios this]] discussion thread.[[/note]]

* [[https://scp-wiki.wikidot.com/scp-3799 SCP-3799]] is a type of snow that expands by dissolving human corpses. Kinda creepy. Then it turns out that it has a memetic effect that makes people view the snow in religious awe and willingly go to die of hypothermia to become fuel. It eventually consumes more than ''40% of the planet''. And even worse, the memetic effect becomes worse over time, either affecting human memory and records, or outright rewriting history in its quest to [[spoiler: make everything pure and uniform]]. By the end, the Foundation has been rewritten into the SCF, Snow Containment Foundation, whose main goal is to contain the snow. And they fail. Ultimately, only a few humans remain, completely convinced that the world has always been covered in snow, and that humans have always lived inside the foundation sites. The snow is finally stopped by someone performing a HeroicSacrifice, after somehow overcoming the memetic effect.

* [[https://scp-wiki.wikidot.com/scp-5000 SCP-5000]] invokes this scenario, mostly consisted of archives and data from the suit which can be used as a PerceptionFilter. A survivor from an alternate universe created an ApocalypticLog from said suit which apparently detailed that the SCP Foundation [[FaceHeelTurn reversed their policy]] of "We die in the dark so that others can live in the light", and instead creates a new objective, [[KillAllHumans the extermination of the human race]]. The main motivation of carrying out an all-out war against humanity isn't clearly stated, though, [[LampshadeHanging as noted by the SCP-5000 user being annoyed at the pretentious usage of redactions in their protocols and instructions used to carry out the assault]], but the user details how several well-known [=SCPs=] such as SCP-096 and SCP-1048 are being used against humanity and how several [=GOIs=] like Church of Broken God and Global Occult Coalition are being decimated left and right. By the end of the logs, [[ApocalypseHow the whole world is now inherited by the newly-freed SCPs]] and [[HumanoidAbomination mutated MTF soldiers]] with praying-mantis like attributes. [[spoiler: If one does some digging through this article, the Foundation's reason for killing the human race is due to the fact that all known human emotions, both good and bad, were ''actually added in'' by a mind-controlling EldritchAbomination [[MindRape that essentially invaded the human subconscious eons ago]] for motives left unknown - and they're so desperate to defeat this thing that to them, exterminating mankind is the ''[[MercyKill more ethical]]'' alternative to allowing the being to go forward with whatever plan it might have in store. Thankfully, one of the last uncorrupted Foundation personnel manages to create a RealityBreakingParadox that acts as a ResetButton that restores the world. But since that universe was reset to ''just'' before the discovery of the entity, there's no way to tell whether or not it will happen again.]]

** ''NK-Class Replication scenario'': An object that is self-replicating or able to create matter out of nothing spirals out of control, and Earth becomes uninhabitable because it's completely covered in [[https://scp-wiki.wikidot.com/scp-505 ink]] or [[https://scp-wiki.wikidot.com/scp-871 cakes]] or [[https://scp-wiki.wikidot.com/scp-1786 coffee]] or what have you.

* [[https://scp-wiki.wikidot.com/scp-5000 SCP-5000]] invokes this scenario, mostly consisted of archives and data from the suit which can be used as a PerceptionFilter. A survivor from an alternate universe created an ApocalypticLog from said suit which apparently detailed that the SCP Foundation [[FaceHeelTurn reversed their policy]] of "We die in the dark so that others can live in the light", and instead creates a new objective, [[KillAllHumans the extermination of the human race]]. The main motivation of carrying out an all-out war against humanity isn't clearly stated, though, [[LampshadeHanging as noted by the SCP-5000 user being annoyed at the pretentious usage of redactions in their protocols and instructions used to carry out the assault]], but the user details how several well-known [=SCPs=] such as SCP-096 and SCP-1048 are being used against humanity and how several [=GOIs=] like Church of Broken God and Global Occult Coalition are being decimated left and right. By the end of the logs, [[ApocalypseHow the whole world is now inherited by the newly-freed SCPs]] and [[HumanoidAbomination mutated MTF soldiers]] with praying-mantis like attributes. [[spoiler: If one does some digging through this article, the Foundation's reason for killing the human race is due to the fact that all known human emotions, both good and bad, were ''actually added in'' by a mind-controlling EldritchAbomination [[MindRape that essentially invaded the human subconscious eons ago]] [[NothingIsScarier for motives left unknown]] - and they're so desperate to defeat this thing that to them, exterminating mankind is the ''[[MercyKill more ethical]]'' alternative to allowing the being to go forward with whatever plan it might have in store. Thankfully, one of the last uncorrupted Foundation personnel manages to create a RealityBreakingParadox that acts as a ResetButton that restores the world. But since that universe was reset to ''just'' before the discovery of the entity, there's no way to tell whether or not it will happen again.]]

* * [[https://scp-wiki.wikidot.com/scp-6187 SCP-6187]] ('From Space With Love') is a species of SpaceWhale, which migrate from star to star, eating smaller spaceborne organisms. They communicate through radio signals, and unfortunately, one has latched onto Earth's broadcasts, and mistaken our planet for a member of its own species - in short, Earth is in danger of literally getting fucked to death.

* A distressingly large number of [[Wiki/SCPFoundation SCP]] objects can cause (or ''have'' caused) TheEndOfTheWorldAsWeKnowIt, to the point where the Foundation is actively predicting and categorizing the different ways the world can end, using the (fictional) "K-Class" classification system. [[note]]Remember that there is [[UnreliableCanon no canon]]. This list is purely for providing general examples and descriptions of explicitly identified scenarios. For more comprehensive lists (of equally dubious reliability), please refer to [[http://scpsandbox2.wikidot.com/k-class-scenarios this]] link and [[http://www.scp-wiki.net/forum/t-225525/k-class-scenarios this]] discussion thread.[[/note]]
** ''AK-Class Madness scenario'': When humanity suffers a mental block on normal activity on a scale massive enough to totally disrupt the lives of those affected. In other words, [[BrownNote something]] makes the world irrevocably go mad. [[http://www.scp-wiki.net/scp-1101 SCP-1101]] has the potential to create such a runaway scenario if a containment breach allows a chain-reaction of people to become exposed to the anomaly, join the debate, and begin to draw other people into the anomaly. [[http://www.scp-wiki.net/scp-571 SCP-571]] and the viral memetic property that gives affected people a compulsive need to spread the meme also carries the risk of causing such an event.
** ''AE-Class Total Allison Eckhart Failure Scenario''[[note]]The letters AE and the name "Allison Eckhart" are the result of semantic corruption in the SCP that uses this scenario.[[/note]]: The Earth is fully contaminated in gaseous anomalous (or non-anomalous) substances. Used once in [[http://www.scp-wiki.net/scp-2565 SCP-2565/Allison Eckhart]], where a Group of Interest obtains the waste samples of the titular semantic pointer and uses them to infect the world, causing every physical object on Earth to be defined, perceived, and only able to be referred to as Allison Eckhart.
** ''CK-Class Restructuring scenario'': It doesn't end the world outright, but the world is so different that it might as well be gone. One example of a CK is [[http://www.scp-wiki.net/scp-140 SCP-140]]. The longer the book grows, the longer the gruesome Daevite civilization in the book survives in real life. Making it long enough would change modern society beyond recognition. Another example is the [[http://www.scp-wiki.net/wrong-proposal Wrong Proposal]], which outright states at the beginning that our history is the ''result'' of a CK-Class. It was initiated primarily because many pre-1900 events equivalent to the ones we know today were loaded with anomalies, leading to Earth becoming a bit of a CrapsackWorld.
** ''EK-Class Evolutionary Restructuring Scenario'': Life on Earth is forcibly evolved into unrecognizable conditions using artificial instigation of the rubber-band nature of evolution. Used in [[http://www.scp-wiki.net/scp-3069 SCP-3069]], where an anomalous underwater structure TwentyMinutesIntoTheFuture threatens to poison the Earth's oceans and accelerate the evolution of life to recreate all aquatic fauna in its image.
** ''EK-class Loss of Consciousness scenario'': When humanity as a whole suffers a loss of self-awareness, that may not kill people but does remove their free will in some form. [[http://www.scp-wiki.net/scp-1427 Can create a scenario where all humanity loses the ability to resist suggestions by whatever authority controls the object.]]
** ''GK-Class Hostile Greenhouse'' scenario: When plant life would severely disrupt the planet. Used in [[http://www.scp-wiki.net/scp-540 SCP-540]] where anomalous weapons cause plants to bloom. It contains a modified ''Tsar Bomba'', a 75 megaton nuclear weapon that would cause a forest to break out over one third of the planet.
** ''GH-0 Dead Greenhouse'': Described as what happened in the [[http://www.scp-wiki.net/document-recovered-from-the-marianas-trench document recovered from the Marianas Trench]] as a result of multiple SCP's breaching containment. Everybody on Earth dies, but the planet is still capable of supporting life.
** ''IK-class Global Civilisation Collapse scenario''. [[http://www.scp-wiki.net/in-the-big-league One story has a]] (perfectly normal, non-anomalous) asteroid that would kill 3 billion people over the next 10 years when it hit Earth being called an IK-Class natural disaster. This could also happen if [[spoiler:there's [[http://www.scp-wiki.net/scp-1238 an overpopulation of rock-eating fish]] that will eventually collapse the Western coast of the United States, not only killing millions of people but inflicting massive damage on the environment, technological infrastructure, and global economy, as well as displacing millions of survivors as refugees and causing a major political crisis. And by "if" we mean "it's happening in about 30 or so years".]]
** ''MK-class Total Loss of Human Consciousness scenario'': All of humanity loses most of their higher-order thinking. The nature of the scenario is used multiple times but was not given a name until the [[http://www.scp-wiki.net/scp-3002 SCP-3002]] was created, where a sapient idea destroys most of the Foundation, infects nearly all of humanity and all information in the world, and forces the Overseer Council to kill 11 of their members. [[spoiler:Because [[ComicBook/VForVendetta ideas are bulletproof]], the story ends on a cliffhanger with two possible outcomes: either Veles, O5-1, [[ResetButton resets the world]], or the idea hijacks all of the population and cuts off their free will. [[DespairEventHorizon The latter is more likely to some extent.]]]] Also, it should be noted the ending doesn't say if the O-5 council was eliminating infected members... Or, the other way around. [[spoiler:Also, [[http://www.scp-wiki.net/scp-3733 SCP-3733]] is implied to take place in a post-MK world.]]
** ''NK-Class Replication scenario'': An object that is self-replicating or able to create matter out of nothing spirals out of control, and Earth becomes uninhabitable because it's completely covered in [[http://www.scp-wiki.net/scp-505 ink]] or [[http://www.scp-wiki.net/scp-871 cakes]] or [[http://www.scp-wiki.net/scp-1786 coffee]] or what have you.
** ''PK-Class Existential Pandemonium Scenario'': A proposed class, in which a higher entity does not have the intelligence needed[[note]]that is, far beyond human intelligence[[/note]] to process higher metanarrative threads of information (essentially, universes higher up on the metanarrative order that can contain lower ones in the form of fiction), and as a result, suffers sensory/cognitive overload. As a result, all lower narratives are compressed into one, wreaking havoc on our reality as each reality overlaps with each other in an unrecognizable mess. This was proposed in relation to the dangerous reality-warper [[http://www.scp-wiki.net/scp-3812 SCP-3812]], but ultimately rejected for being deemed implausible. [[spoiler:In fact, the process was well on its course.]]
** ''QK-Class Quantum Degeneracy scenario'': When earth disintegrates into a quantum mess. [[http://www.scp-wiki.net/scp-2460 SCP-2460]], a piece of anomalous dark matter, can convert normal matter into more dark matter like itself, causing them to maintain their shape but lose the repulsion between particles, effectively causing objects to “phase through” each other. Should the object collide with earth, it will turn the entire earth into a giant bulk of orbiting non-interacting matter.
** ''SK-Class Dominance Shift scenario'': The dominant species being made extinct or forced into subjugation by another species. This could happen [[http://www.scp-wiki.net/scp-752 if a currently contained species became aware of, then began direct competition with]] humanity; when [[http://www.scp-wiki.net/scp-1157 a replicating human]] is unable to be contained and it takes over the planet, or [[spoiler: [[http://www.scp-wiki.net/scp-1000 when humanity rose up against a dominant sapient species during our pre-history and took control over the planet.]]]].
** ''TK-Class Causal Restructuring Event'': The world or part of it is changed to a state similar to an earlier era. Described in the article for [[http://www.scp-wiki.net/scp-1297 SCP-1297]], a jar of human toenail clippings that rolls history back by up to a century per nail clipping removed from it. [[spoiler: An addendum to the article implies this has ''already happened'' -- there is one clipping missing.]]
** ''UK-Class Global Irradiation Event'': The world becomes polluted with radioactivity. Mentioned in [[http://www.scp-wiki.net/scp-2493 SCP-2493]], where the potential cause is the body of an extradimensional person made of antimatter colliding with Earth's atmosphere.
** ''XK-Class End of the World scenario'': Was originally used in relation to religious-based ends of the world, but shifted to an "all-purpose" of the end of the world scenario that could be anything from "humans died" right up to "the death of all life on the planet" or even "[[EarthShatteringKaboom the entire planet is exploded]]". It's bad news, whatever the end result is. [[http://www.scp-wiki.net/dr-clef-s-proposal Dr. Clef's proposed SCP-001]] if moved in confluence with a breach in SCP-995[[note]]This is referring to a deleted SCP. The writer chose not to change it when 995 was deleted and replaced.[[/note]] and the opening of [[http://www.scp-wiki.net/SCP-616 SCP-616]] is just one example.
** ''YK-Class Entropic Annihilation Event'': Causing the entire universe to reverse its flow of entropy, effectively turning time backwards. [[spoiler: [[http://www.scp-wiki.net/scp-2700 SCP-2700]], [[UsefulNotes/NikolaTesla Tesla’s]] DeathRay, contains a bundle of anomalously contained particles that behave against normal entropy as its core. Should the death ray fire, the particles would be released and the entire universe will be converted to reverse entropy.]] A YK event [[spoiler:happens every two weeks inside [[http://www.scp-wiki.net/scp-2123 SCP-2123]].]]
** ''ZK-Class Reality Failure Event'': Reality as we know it is destroyed, and may or may not apply to multiple other realities. One of [[http://www.scp-wiki.net/sandrewswann-s-proposal SCP-001's proposals]] mentions a non-zero possibility of a [[ApocalypseHow total metaphysical annihilation of the universe]]. [[spoiler: [[TheFourthWallWillNotProtectYou Because they are the authors of the universe.]]]]
** ''ZK-0 Reality Failure'': Similar to above, but the universe would still exist, just not under our laws. The universe on the other side of [[http://www.scp-wiki.net/scp-319 SCP-319]] is in a lower energy state, so should the device fail to contain the universe portal, a [[http://en.wikipedia.org/wiki/False_vacuum#Vacuum_metastability_event vacuum metastability event]] would occur, bringing the entire universe into a lower energy state that can’t support anything our current universe has.
* Some [=SCPs=] and tales indicate the world has ''already ended several times''. In some cases the Foundation survivors used some version of time travel or retconning to prevent the events that led to the disaster. More disturbing are incidents where the Foundation, seemingly utilizing [[http://www.scp-wiki.net/scp-2000 SCP-2000]], simply cleaned up the surface and repopulated the world with clones, rewriting history to account for any inaccuracies, with the implication that ''nobody knows how many times they've done this''.[[note]]If the Wrong Proposal for SCP-001 is to be believed, the minimum amount of times the world has been reset is estimated to be a number between 22 and 35 if one does the math using the corpse inside SCP-2000 and the start of the new world in the 20th Century, when SCP-2000 began to take shape, as guides, assuming each reset followed all modern guidelines for using SCP-2000.[[/note]] And the cloning system that allows it is in bad shape.
* A few alternate dimensions have suffered this fate, usually due to an improperly contained SCP. The Foundation also [[NiceJobBreakingItHero accidentally caused this in at least one reality]] by giving them a vaccine which turned out to be a SterilityPlague. [[spoiler:[[http://www.scp-wiki.net/scp-2935 SCP-2935]] is a case where all life on the planet is wiped out without doing outright damage to the planet itself.]]
* In 2018 the site ran the [[http://www.scp-wiki.net/doomsday-contest Doomsday Contest]], in which each team had to come up with four documents centred around a unique __-Class Scenario of their own invention. There are 44 teams, so that's potentially 44 new world-ending scenarios from a single contest. They include:

* [[http://www.scp-wiki.net/scp-3799 SCP-3799]] is a type of snow that expands by dissolving human corpses. Kinda creepy. Then it turns out that it has a memetic effect that makes people view the snow in religious awe and willingly go to die of hypothermia to become fuel. It eventually consumes more than ''40% of the planet''. And even worse, the memetic effect becomes worse over time, either affecting human memory and records, or outright rewriting history in its quest to [[spoiler: make everything pure and uniform]]. By the end, the Foundation has been rewritten into the SCF, Snow Containment Foundation, whose main goal is to contain the snow. And they fail. Ultimately, only a few humans remain, completely convinced that the world has always been covered in snow, and that humans have always lived inside the foundation sites. The snow is finally stopped by someone performing a HeroicSacrifice, after somehow overcoming the memetic effect.
* [[http://www.scp-wiki.net/scp-4005 SCP-4005]] is an odd example in that while the world as we know it completely ends, humanity as we know it doesn't. They are all simply offered something better, along with a pilgrimage to follow to get there. One by one, they get the visions of where, what, and how. And one by one, they just ''leave''. And in the end, the Earth is completely empty, because every last human just up and walked away into what is implied to be a genuine, extradimensional Utopia. It'd be played straighter if it was a trap all along, but we never get any such hints.
* [[http://www.scp-wiki.net/revised-entry Revised Entry]] has SCP-173 gain the ability to [[MesACrowd self-replicate]], doubling to the point where instances become impossible to contain. They escape, begin massacring the populations of North and South America. Groups of thousands are powerful enough to destroy Foundation facilities and they even manage to ''rip [[NighInvulnerability SCP-682]] to pieces.'' The O5's declare it an XK-Class, pull the few surviving Foundation staff out, then conduct [[NukeEm a saturation nuclear bombing campaign]]. The Americas are declared Containment Zone X1, and all remaining Foundation resources and the entire remaining world's navies are to constantly patrol the coasts and scan the oceans, making sure nothing escapes. The final addendum confirms SCP-173 has been spotted in Wales...
* [[http://www.scp-wiki.net/scp-5000 SCP-5000]] invokes this scenario, mostly consisted of archives and data from the suit which can be used as a PerceptionFilter. A survivor from an alternate universe created an ApocalypticLog from said suit which apparently detailed that the SCP Foundation [[FaceHeelTurn reversed their policy]] of "We die in the dark so that others can live in the light", and instead creates a new objective, [[KillAllHumans the extermination of the human race]]. The main motivation of carrying out an all-out war against humanity isn't clearly stated, though, [[LampshadeHanging as noted by the SCP-5000 user being annoyed at the pretentious usage of redactions in their protocols and instructions used to carry out the assault]], but the user details how several well-known [=SCPs=] such as SCP-096 and SCP-1048 are being used against humanity and how several [=GOIs=] like Church of Broken God and Global Occult Coalition are being decimated left and right. By the end of the logs, [[ApocalypseHow the whole world is now inherited by the newly-freed SCPs]] and [[HumanoidAbomination mutated MTF soldiers]] with praying-mantis like attributes. [[spoiler: If one does some digging through this article, the Foundation's reason for killing the human race is due to the fact that all known human emotions, both good and bad, were ''actually added in'' by a mind-controlling EldritchAbomination [[MindRape that essentially invaded the human subconscious eons ago]] [[NothingIsScarier for motives left unknown]] - and they're so desperate to defeat this thing that to them, exterminating mankind is the ''[[MercyKill more ethical]]'' alternative to allowing the being to go forward with whatever plan it might have in store. Thankfully, one of the last uncorrupted Foundation personnel manages to create a RealityBreakingParadox that acts as a ResetButton that restores the world. But since that universe was reset to ''just'' before the discovery of the entity, there's no way to tell whether or not it will happen again.]]