SCP Foundation

Каждое сочетание этих букв использовалось на нашей вики как минимум дважды. Они представлены в алфавитном порядке, начиная с событий класса К, заканчивая другими. (GH занял одно из первых мест в силу своего старшинства).

Для одноразовых событий и таких, которые использовались только в -J объектах, отдельная таблица представлена ниже.

События со знаком * использовались минимум 5 раз с одинаковым определением.
События с символом © использовались минимум 10 раз с одинаковым определением, которое может считаться устоявшимся. А еще вы должны мне 5¢ за их использование.
События с символом 🎖️ использовались минимум 100 раз с одинаковым определением, которое может считаться "prominent."

Общепринятое название: Конец света класса AK
Использование: 16 объектов, 1 рассказ, # других статей
Основное определение: Относится к меметически распространяемой модели поведения или "безумию". Может носить апокалиптический характер (например, люди будут игнорировать свою потребность в пище или выживании) или просто радикально изменит общество в связи с этой моделью.

Некоторые из этих статей просто указывают "Конец света класса AK" без какого-либо определения.
Другие названия: Событие класса AK "Безумие", **Событие класса AK "Заразительное безумие" класса АК, Событие перестройки общества класса AK "Безумие", Событие класса АК "Коллективное безумие"

Объекты: SCP-PL-200, SCP-571, SCP-1101, SCP-1118-RU, SCP-1985, SCP-2001-EX, SCP-3060, SCP-3443, SCP-4547, SCP-5586, SCP-6081, SCP-6174, SCP-6557, SCP-7650, SCP-7720, SCP-8155
Рассказы и другие статьи: Перезагрузка, или Как я перестал бояться и полюбил апокалипсисы

Другие употребления

Общепринятое название: Событие класса ADK "Полная аномальная дестабилизация"
Использование: 4 объекта, 1 рассказ, 0 других
Основное определение: Событие такого класса происходит, когда нечто "аномальное" получает контроль над Землей. Обычно начинается спустя 1-3 года после неких событий, повлекших вымирание человечества, или после конца света класса SK "Смена господства".
Другие названия: Отсутствуют

Объекты: SCP-3309, SCP-6016, SCP-6070, SCP-7423
Рассказы и другие статьи:: UMBRAL_MIGRATORY_SEQUENCE.txt

Общепринятое название: Конец света класса CK "Реструктуризация реальности"
Использование: 97 объектов, 19 рассказов, 9 других статей
Основное определение: Реальность меняется каким-либо божеством/скульптором реальности/ретропричинным изменением истории/и т.д. Это могут быть как и радикальные, крупные изменения, которые можно по праву назвать концом света, так и небольшие "локализованные" изменения. (Так же смотри RK)
Другие названия: События класса CK "Реструктуризация реальности", Событие класса CK "Реструктуризация современного общества", Событие класса CK "Конец реальности", Событие класса CK "Реструктуризация истории".

Объекты: D. Ulysees Foole's Proposal, Kate McTiriss's Proposal, Not-a-Seagull Proposal, WMDD's Proposal, Wrong Proposal, SCP-079-INT, SCP-095-J, SCP-125-DE, SCP-140, SCP-CN-166, SCP-179, SCP-591, SCP-1012, SCP-1237, SCP-1425, SCP-1516-KO, SCP-1961-RU, SCP-1968, SCP-1985, SCP-2046, SCP-2047, SCP-2311, SCP-2330, SCP-2702, SCP-2743, SCP-2901, SCP-2975, SCP-3189, SCP-3391, SCP-3426, SCP-3443, SCP-3480, SCP-3498, SCP-3557, SCP-3600, SCP-3648, SCP-3672, SCP-3739, SCP-3742, SCP-3487, SCP-3797, SCP-3799, SCP-3919, SCP-3936, SCP-3997, SCP-3999, SCP-4001, SCP-4010, SCP-4071, SCP-4121, SCP-4255, SCP-4260, SCP-4273, SCP-4656, SCP-4804, SCP-4847, SCP-5157, SCP-5500, SCP-5616, SCP-5715, SCP-5883, SCP-6099, SCP-6129, SCP-6140, SCP-6460, SCP-6500, SCP-6511, SCP-6525, SCP-6535, SCP-6548, SCP-6793, SCP-6820, SCP-6859, SCP-7095, SCP-7234, SCP-7412, SCP-7579, SCP-7584, SCP-7585, SCP-7558, SCP-7757, SCP-7771, SCP-7777, SCP-7817, SCP-7891, SCP-7997, SCP-8008, SCP-8079, SCP-8121, SCP-8317, SCP-8425, SCP-8547, SCP-8802, SCP-8886, SCP-8907, SCP-8990
Рассказы и другие статьи: The Beast Beneath The Library, Of Multiverses and Dandelion Wine, Girls' Night Out: Dressing Up, Incident 239-B - Clef-Kondraki, Incident Zero - Part 2, Incident Zero - Part 3, Memetics and Infohazards Division Orientation, Persephone Project, Recovered Data File, Fools of Us All, It's All True, Changes All That Is Around Me, A Hole in the Wall on Mars, Secure Facility Dossier Reliquary Area-27, Mobile Task Force Psi-7 "Home Improvement Hub", The Adventures of Lord Blackwood, Explorer and Gentleman, The Hanged King's Tragedy, Experiment Log T-98816-OC108/682, Excerpts From "How To Survive When Reality Doesn't", by Alto Clef, Over(thinking) the Rainbow, Good Fences Make Good Neighbors, Change, SCP TV Pilot: Into the Deep End, Not-So-Lucky Triple Sevens, The Bold and the Dutiful (Part One), Resurrection, Milk Hub, The Gardeners Of The Orchard

Inconsistent Uses

Most Common: EK-Class End of Human Consciousness
Used in: 10 SCPs, 2 Tales, 1 Other
Primary definition: Total loss of human consciousness. Sometimes just obliviated due to complete memetic replacement or corruption. (See also MK, ED-K)
Alternative titles: N/A

SCPs: SCP-042-IT, SCP-1427, SCP-1985, SCP-2001-EX, SCP-2007, SCP-338, SCP-3498, SCP-4741, SCP-6494, SCP-7650
Tales and other articles: Stage Fright, Richardson Island, Self.Similar.

Inconsistent Uses

No consistent usage.

Inconsistent Uses

Most Common: GH-0 'Dead Greenhouse' scenario
Used in: 15 SCPs, 1 Tales, 1 Other
Primary definition: Originally appearing in the Marianas Trench document, where it meant that humans are endangered/extinct but Earth is still fit for habitation. Usage of G-Class scenarios in SCPs is inconsistent but usually involves habitability.
Alternative titles: GH-Class "Dead Greenhouse" event, GK-Class End of the World Scenario, GK-class hostile-greenhouse scenario, GK Class Climate Inversion event, GH-Class "Colorless Plague" end-of-humanity event, GK-Class "Broken Greenhouse"

SCPs: SCP-540, SCP-1751, SCP-2029, SCP-2543, SCP-2554, SCP-2702, SCP-4237, SCP-4547, SCP-4568, SCP-5055, SCP-5691, SCP-6014, SCP-6060, SCP-6557, SCP-6872, SCP-7070
Tales and other articles: Document Recovered from the Marianas Trench, SCP-2305-A Extended Documentation Log

Inconsistent Uses

Most Common: HK-Class Deific Subjugation Scenario
Used in: 10 SCPs, 3 Tales, 1 Other
Primary definition: A god shows up and takes over.
Alternative titles: N/A

SCPs: SCP-3480, SCP-3703, SCP-4343, SCP-5099, SCP-5501, SCP-5506, SCP-6167, SCP-6777, SCP-7616, SCP-7606, SCP-8008
Tales and other articles: Secure Facility Dossier Reliquary Area-27, Four Knights Tango, Garfield Timeline, Your Demise Explained

Inconsistent Uses

Most Common: IK-Class Collapse of Global Civilization Scenario
Used in: 15 SCPs, 2 Tales, # Other
Primary definition: Civilization collapses.
Alternative titles: N/A

SCPs: Wrong Proposal, SCP-CN-166, SCP-1238, SCP-1985, SCP-4043, SCP-4163, SCP-4224, SCP-4547, SCP-5539, SCP-5802, SCP-6606, SCP-6789, SCP-7021, SCP-7314, SCP-7817,
Tales and other articles: An Faq Part Two; Or, Your Hume Questions Answered, Project Morpheus

Inconsistent Uses

Most Common: LK-Class species transmutation scenario
Used in: 10 SCPs, # Tales, # Other
Primary definition: Something about humanity is altered.
Alternative titles: LK-class restructuring event, LK-Class Personality Transmutation Event, LK-Class Change of Species Scenario

SCPs: Kate McTiriss's Proposal, SCP-003, SCP-2690, SCP-3199, SCP-3335, SCP-3368, SCP-3419, SCP-4738, SCP-6872, SCP-ZH-9288-EX,
Tales and other articles: N/A

Inconsistent Uses

Most Common: MK-Class "End of Human Consciousness" scenario
Used in: 6 SCPs, 1 Tales, # Other
Primary definition: Total loss of human consciousness. (See also EK)
Alternative titles: N/A

SCPs: SCP-3002, SCP-3125, SCP-4568, SCP-5737, SCP-6715, SCP-6872
Tales and other articles: Your Last First Day

Inconsistent Uses

Most Common: NK-Class "Grey Goo" Scenario
Used in: 27 SCPs, 1 Tales, # Other
Primary definition: A self-replicating SCP or object reproduces out of control, causing contamination to the planet, filling/replacing the world with itself, or similar situations. (Named for a hypothetical scenario where self-replicating nano-machines malfunction and turn the whole world into goop.)
Alternative titles: N0K-Class "Contagious Material" Scenario, NK-Class Type 2

SCPs: Debhida Eulalie O'Foolbert's Proposal, SCP-505, SCP-1037, SCP-1786, SCP-1985, SCP-2102, SCP-2288, SCP-2631, SCP-2794, SCP-2921, SCP-3800, SCP-3856, SCP-3925, SCP-4143, SCP-4318, SCP-4495, SCP-4740, SCP-4950, SCP-5932, SCP-6557, SCP-7038, SCP-7354, SCP-7509, SCP-7579, SCP-7634, SCP-8065, SCP-8702
Tales and other articles: The Bacterium (Part Two)

No consistent usage.

Inconsistent Uses

Most Common: PK-Class “All-In-One” Existential Pandaemonium Event
Used in: 2 SCPs, # Tales, # Other
Primary definition: An event in which a hyperreal consciousness collapses all hyporealities into the same meta-space, resulting in total narrative collapse from incomprehensibility and annihilation of consciousness.

SCPs: SCP-3812, SCP-5309
Tales and other articles: N/A

Inconsistent Uses

Most Common: QK-class quantum degeneracy end-of-the-world scenario
Used in: 3 SCPs, # Tales, # Other
Primary definition: A specific physics-based end of the world. For other physics-based EOTW, see VK, ZK, and YK.
Alternative titles: N/A
SCPs: SCP-2460, SCP-4353, SCP-5541
Tales and other articles: N/A

Most Common: RK-Class Restructuring Scenario
Used in: 5 SCPs, 1 Tales, # Other
Primary definition: Interchangeable with CK-Class, see that definition.
Alternative titles: RK-class "out-competition" restructuring scenario (listed as different than CK, but no detail)

SCPs: SCP-816, SCP-1985, SCP-2464, SCP-3600, SCP-3800, SCP-7035
Tales and other articles: Reboot or: How I Learned to Stop Worrying and Love the Apocalypses

Inconsistent Uses

Most Common: SK-Class Dominance Shift Scenario
Used in: 28 SCPs, 1 Tales, # Other
Primary definition: Another species or civilization surpasses humanity as dominant species, or vice versa.
Alternative titles: N/A

SCPs: D. Ulysses Foole's Proposal, WMDD's Proposal, SCP-752, SCP-1000, SCP-1985, SCP-2309, SCP-2480, SCP-3675, SCP-3683, SCP-3778, SCP-4043, SCP-4318, SCP-5657, SCP-5745, SCP-6140, SCP-6557, SCP-6606, SCP-6772, SCP-6783, SCP-7038, SCP-7047, SCP-7102, SCP-7382, SCP-7401, SCP-7778, SCP-8016, SCP-8065, SCP-8075
Tales and other articles: SCP the Anime, part 4 (Gears/Iceberg, Clef/Kondraki, Rights/Light, Kain, monkey!Bright)

Inconsistent Uses

Most Common: TK-Class Causal Restructuring Event
Used in: 3 SCPs, 1 Tales, # Other
Primary definition: A massive CK-Class restructuring took place that resulted in the breaking and repair of the timeline. But like a broken vase, the repaired timeline is flawed, with events that don't line up and things that happened without a cause.
Alternative titles: TK-Class Broken Timeline Scenario

SCPs: SCP-1297, SCP-5235, SCP-5711, SCP-7381
Tales and other articles: Incident Zero - Part 5

Inconsistent Uses

No consistent usage.

Inconsistent Uses

Most Common: (Assorted Physics EOTW)
Used in: 5 SCPs, 1 Tales, # Other
Primary definition: No single consistent usage, but basically always used in physics-heavy articles. See also ZK, YK, and QK.
Alternative titles: VK-Class end-of-the-world event, VK-Class hazard, VK-Class "Localized Dimensional Collapse" scenario

SCPs: Kate McTiriss's Proposal, SCP-2821, SCP-2943, SCP-3685, SCP-5470
Tales and other articles: Halloween on 17th Street

Inconsistent Uses

Most Common: WK-Class Mass Extinction Event
Used in: 5 SCPs, # Tales, # Other
Primary definition: One or multiple non-human species become extinct.
Alternative titles: N/A

SCPs: D. Ulysses Foole's Proposal, SCP-3427, SCP-4690, SCP-5539, SCP-8007
Tales and other articles: N/A
Inconsistent Uses

Most Common: XK-Class End-of-the-World Scenario
Used in: 96 SCPs, 29 Tales, # Other
Primary definition: Most common and broadest meaning, covers just about any apocalypse. Religious apocalypse, humanity destroyed, Earth destroyed, the universe destroyed, etc.

Some XK scenarios may fit well under other scenarios, such as ZK, but these definitions aren't mandatory. (Needs update.)
Alternative titles: XK-class Type Alpha (scorched earth) end of the world scenario, XK-class Type Omega (religious) end of the world scenario, XK-Class Vacuum Decay, XK-Class Extinction Event Scenario, XK-Class Mass Extinction Event, PATMOS XK-class end-of-the-world scenario, XK-734, XK-918, XK-337

SCPs: Dr Clef's Proposal, D. Ulysses Foole's Proposal, Kate McTiriss's Proposal, k1s10r0d's Proposal, Pickman-Blank Proposal, S. D. Locke's Proposal, TwistedGears-Kaktus Proposal, WMDD's Proposal, SCP-ES-012, SCP-ES-076, SCP-ES-084, SCP-152, SCP-CN-166, SCP-179, SCP-188-KO, SCP-227, SCP-231, SCP-300-DE, SCP-435, SCP-582, SCP-616, SCP-861, SCP-1055, SCP-1259, SCP-1297, SCP-1348, SCP-1514, SCP-1518, SCP-1591, SCP-1678, SCP-1714, SCP-1719, SCP-1748, SCP-1985, SCP-2073, SCP-2100, SCP-2217, SCP-2128, SCP-2317, SCP-2326, SCP-2440, SCP-2493, SCP-2631, SCP-2853, SCP-2877, SCP-2950, SCP-2975, SCP-2995, SCP-3004, SCP-3007, SCP-3013, SCP-3069, SCP-3192, SCP-3272, SCP-3496, SCP-3600, SCP-3742, SCP-3762, SCP-3768, SCP-3769, SCP-3805, SCP-3812, SCP-4001, SCP-4043, SCP-4075, SCP-4077, SCP-4094, SCP-4121, SCP-4242, SCP-4262, SCP-4293, SCP-4343, SCP-4547, SCP-4646, SCP-6557, SCP-4908, SCP-5092, SCP-5776, SCP-6055, SCP-6187, SCP-6500, SCP-6959, SCP-6998, SCP-7021, SCP-7171, SCP-7459, SCP-7516, SCP-7616, SCP-7676, SCP-7817, SCP-8065, SCP-8075, SCP-8235 SCP-8802, SCP-8728, SCP-8929

Most Common: Событие класса XK-Δ "Солнечная сингулярность".
Hub: Daybreak, daybreak tag
Used in: 2 SCPs, 14 Tales
Primary Definition: A scenario in which the sun undergoes a "solar singularity" event, causing it to convert all living things its light touches into gelatinous monsters that combine and blend with each other.

SCPs: S. D. Locke's Proposal, D. Ulysses Foole's Proposal

Tales and other articles: Before Twilight, Heart and Sol, Hotdog Hotdog Hot Diggity Dog, How Was Your Day, May The Sun Never Set On The British Empire, Orange Mind, The Little Robot that Could, The Wasteland, This Broken Sky, This Cruel Moon, Three Thousand to One, Unexpected light, Umbra

Most Common: (Assorted Physics EOTW)
Used in: 10 SCPs, # Tales, # Other
Primary definition: Basically always a physics-based apocalypse, usually has a specific sub-designation. See also ZK, VK, and QK.
Alternative titles: YK-Class Entropic Annihilation Event, YK-class end of the universe scenario, YK-Class Reality Restructuring Event, YK-Class Restructuring scenario, YK-class Vacuum Decay, YK Subjective Reality Reconstruction Scenario

SCPs: D. Ulysses Foole's Proposal, WMDD's Proposal, SCP-2123, SCP-2216, SCP-2305, SCP-2400, SCP-2700, SCP-3049, SCP-3391, SCP-PL-106

Tales and other articles: N/A

Inconsistent Uses

Most Common: ZK-Class Reality Failure Scenario
Used in: 40 SCPs, 6 Tales, 1 Other
Primary definition: Reality is fundamentally broken or eliminated. Usually due to physics stuff or an SCP that annihilates things by nature.

Sometimes this happens in a limited "localized" area. Originally used in physics-heavy articles but may have graduated to broader use. (See YK, VK, and QK).
Alternative titles: ZK-0 Reality Failure Scenario, ZK-λ-Class Cosmic Fragmentation Scenario, ZK-Class End of Reality scenario, Z1-Class reality reset

SCPs: Arbelict's Proposal, D. Ulysses Foole's Proposal, Kate McTiriss's Proposal, not_a_seagull's Proposal, S Andrew Swann's Proposal, SCP-319, SCP-591, (RU), SCP-1142, SCP-1964-EX, SCP-2470, SCP-2612, SCP-2908, SCP-3319, SCP-3426, SCP-3545, SCP-3600, SCP-3742, SCP-3999, SCP-4055, SCP-4121, SCP-4591, SCP-4656, SCP-4828, SCP-4839, SCP-4847, SCP-5103, SCP-5500, SCP-5647, SCP-6281, SCP-6557, SCP-7005, SCP-7215, SCP-7503, SCP-7515, SCP-7771, SCP-7888, SCP-7909, SCP-8094, SCP-8192, SCP-8235
Tales and other articles: Incident Zero - Part 2, Re: You Want Happy Endings?, Yesterday, Jolly Cooperation, Experiment Log T-98816-OC108/682, A Story From A Future, It's Not Real, It Never Was, You Pathetic Fools

Inconsistent Uses

Most Common:ÞK-class Extradimensional Diplomatic Breakdown scenario
Used in: 4 SCPs, 0 Tale, 0 Other
Primmary Definition: Diplomatic relations with a powerful extradimensional organization (e.g., the Three Moons Initiative) break down.
Alternative titles: N/A

SCPs: SCP-4587, SCP-5298, SCP-7157, SCP-7162
Tales and other articles: N/A

Most Common: Lifted Veil Scenario/Broken Masquerade Scenario
Used in: 57 SCPs, 5 Tales, 1 Other
Primary definition: The Foundation or anomalous become public knowledge. See the Broken Masquerade canon for a possible aftermath.

See also "Inconsistent Uses" in SK-Class. (Needs update.)
Alternative titles: LV-Zero "Lifted Veil" scenario, ßK-Class "Lifted Veil" scenario, Broken Masquerade scenario, BK-Class Broken Masquerade Scenario, SK-Class "Broken Masquerade" scenario, X-Class 'Lift of the Veil' scenario, BM-Class "Broken Masquerade" Scenario

SCPs: TwistedGears-Kaktus Proposal, SCP-185-DE, SCP-1717-EX, SCP-2001-EX, SCP-2217, SCP-2238, SCP-3002, SCP-3396, SCP-3731, SCP-4237, SCP-4410, SCP-4568, SCP-4675, SCP-4710, SCP-4861, SCP-4997, SCP-5417, SCP-5526, SCP-5304, SCP-6000, SCP-6002, SCP-6014, SCP-6020, SCP-6041, SCP-6021, SCP-6140, SCP-6146, SCP-6314, SCP-6821, SCP-6889, SCP-6942, SCP-7002, SCP-7021, SCP-7030, SCP-7101, SCP-7140, SCP-7509, SCP-7527, SCP-7548, SCP-7578, SCP-7800, SCP-7817, SCP-7996, SCP-7999, SCP-8028, SCP-8111, SCP-8241, SCP-8245, SCP-8266, SCP-8300, SCP-8320, SCP-8359, SCP-8430, SCP-8718, SCP-8777, SCP-8800, SCP-8969
Tales and other articles: CryogenChaos' Comment Tales, Person of Interest File #2273/01, Aftermath, The Reassembled One, Fragments, History lesson

Most Allison Eckhart: AE-Class Allison Eckhart Allison-Eckhart Breathability Scenario
Allison Eckharts tagged: 3 SCPs, 1 Tales, 0 Other
Primary definition: Allison Eckhart
Alternative Allison Eckharts: AE-Class Total Allison Eckhart Failure Scenario, Broken Allison Eckhart scenario

Allison Eckharts: SCP-2565, SCP-3294, SCP-4293
Allisons and other Eckharts: Unclogging the Multiverse's Trash

Most Common: BI-Class (Before Invasion) Scenario
Used in: 1 SCP, 1 Tale, 0 Other
Primmary Defiinition: A K-Class scenario, particularly an invasion from another dimension, is imminent. (See DK-Class in one-offs, Russian K Scenario List)
Alternative titles: N/A

SCPs: SCP-2470 (RU)
Tales and other articles: The Bacterium (Part Two) ||

Most Common: CC-Class "Collapse of Chemistry" Scenario
Used in: 3 SCPS, # Tales, # Other
Primary Definition: The laws of physics are altered in a way so that the chemistry relying on the carbon element no longer provides the conditions suitable for creating life.

SCPs: SCP-5814, SCP-6217, SCP-6872

Most Common: TTK-Class Tartarean-Intrusion Scenario
Used in: 4 SCPs, # Tales, # Other
Primary Definition: A K-Class Scenario in which one or more tartarean dimensions (Hell, Hades, etc.) gain influence over baseline reality.
Alternative Titles: N/A

SCPs: SCP-6607, SCP-7304, SCP-7616, SCP-7821
Tales and other articles: N/A

Inconsistent Uses
N/A

Unspecified K-Class (Needs update.)

SCPs: SCP-1964, SCP-2002, SCP-2943, SCP-3272, SCP-3309, SCP-3319, SCP-3391, SCP-3519, SCP-3841, SCP-3856, SCP-3868, SCP-4260, SCP-4293, SCP-4753, SCP-4908, SCP-5243, SCP-6044, SCP-7555, SCP-7776, SCP-7877, SCP-8566

Tales and other articles: Application to Form MTF Mu-3: Documents, A Price to be Paid, Can Haz Memes, Change In The House Of The Flies, Forgiveness, How Dr. Clef Contained Christmas!, Old Kansas Sector ~ 2: Tabloid, On the Outskirts, The First Sailors, Where Have You Been All My Life, Where Is This Going?, In Response To Nuclear Warheads, Visions of the Future, Of Memes and Counterconcepts, Many Last Words, INNER-SPACE, Stealing Something Else, Santa Claus Procedures: Part 2, Nullvoid, Agent Choudhury Files an Insurance Claim, Nico's Proposal, Not Ready for Prime Time, SCP-001 — Wikipedia, Sammy Skipper's Fact of the Day, Welcome to Bonkers, The Kids Aren't Alright, Secure Facility Dossier: Site-222

These scenarios were created for the 2018 Doomsday Contest. If you were a team member for a scenario, please feel free to provide a definition or otherwise update your apocalypse! (Also maybe double-check links, some of these SCP numbers were very similar.)

Edit: Some of these (such as ΩK and EDK) have gone on to become part of extensive canons, so I have added links to tags for people who want to explore them deeper.

*'s represent scenarios with 5+ articles on the contest page (Again, please update! I just used the hub out of —laziness--- expediency.)

Scenario: ℵK-Class "Foundation Apotheosis" Scenario
Hub: Apotheosis Hub, apotheosis tag
Used in: 1 SCP, 1 Tale, 0 Other
Definition: A state of affairs in which all humanity that remains exists within Foundation containment.
Alternative titles: אK-Class "Foundation Apotheosis" scenario
SCPs: SCP-3731
Tales and other articles: Though I Know Not What You Are, Twinkle, Twinkle, Little Star

Scenario: TPK-Class "Thaumaturgic Proliferation" Scenario
Hub: Apotheosis Hub, apotheosis tag
Used in: 4 SCPs, 5 Tales, 0 Other
Definition: A scenario in which all of humanity gains powerful thaumaturgic abilities.
SCPs: SCP-3396, SCP-3731, SCP-3829, SCP-4420
Tales and other articles: The Shape of a Gun, A New Age of Magic, A Farewell to Arms, Thrive , Though I Know Not What You Are, Twinkle, Twinkle, Little Star,

Scenario: ΩK-Class ("End-of-Death") Scenario
Hub: End of Death Hub, end-of-death tag
Used in: 15 SCPs, 8 Tales, 2 Other
Definition: Immortality is forced upon all life, without any other biological change.
SCPs: SCP-3984, SCP-3287, SCP-3866, SCP-3448, SCP-4514, SCP-4725, SCP-2304, SCP-4935, SCP-4260, SCP-4206, SCP-4979, SCP-6292, SCP-6872, D. Ulysses Foole's Proposal, SCP-6755

Tales and other articles: In The Clutches Of Life, ΩK, Excerpts From The Societal Census Programme ΩK-Class Report, GRANT REQUEST FOR THE PERFECTION OF BRAIN TRANSPLANTS FOR IDENTITY PERPETUATION AS TREATMENT FOR AGE-IMPAIRED IMMORTALITY, 'Hypnotraline' (TR7K2/2UD9X/53GN8), With The Reaper On Retirement, ii tab po c h20 qhs prn pain, Tales Of The Ethics Committee: 5 Reasons The Foundation Wants A Robot Army, The Doctor's Dilemma, Project Damnerung

Scenario: ED-K-Class "Lethe" Scenario
Hub: Team Fuhgeddaboutit Hub, part of the Ad Astra Per Aspera canon (tag)
Used in: 8 SCPs, 5 Tales, 1 Other
Definition: A high number of ED-K Lethe Events occurring at a rate that both noticeably and negatively impacts human society and results in public awareness of the SCP-3848 phenomenon.
SCPs: SCP-3484, SCP-3848, SCP-4427, SCP-5013, SCP-6533, SCP-322, SCP-7798, SCP-8200
Tales and other articles: Excerpt from The Astrolabe Institute Journal, 'Schulman-NY Programmable Mnestic Device' (AC34D/NC77Q/95DCS), Paperpushing, Headache, Oceanus, Father to All, 25/12/2047

Scenario: End-of-World K/O Failure Scenario
Hub: K/O Failure Scenario Hub
Used in: 2 SCPs, 1 Tales, 2 Other
Definition: Any scenario in which the Shark Punching Centre is compromised in such a way that it is permanently and utterly unable to complete its mission. Used by the Shark Punching Centre.
SCPs: SCP-3760
Tales and other articles: SPC-001, PeppersGhost's Proposal, I guess., After They Broke Our Fists, SPC-172-J

Scenario: MA-Class Mass Animation Scenario
Hub: Mass Animation Hub
Used in: 1 SCPs, 4 Tales, 1 Other
Definition: Everything with a face on it comes to life.
SCPs: SCP-3406
Tales and other articles: Misery Makes Company, The Three Documents of "The Artist Formerly Known As Chuck", UF-00031, Serving the Twin Cities Since 2021, Chaos Praxis

Scenario: BE-Class "Migration" End-of-Consciousness Scenario
Hub: Team Bird Hub, team-bird tag
Used in: 5 SCPs, 5 Tales, 2 Other
Definition: The replacement of a significant portion of human consciousness with an incompatible lesser mental state. In Team Bird, this occurred only after Thoth — a hostile avian deity who deemed humanity a fallen race — banished human consciousness as punishment and allowed an alien, avian meme to take its place. Later corresponded with the transformation of humans into bird-like abominations.
Alternative Title: BE-Class "Mental Migration" End-of-Thought Scenario
SCPs: SCP-3662, SCP-3296, SCP-3362, EE-3570, SCP-3632
Tales and other articles: Join the Flock, Tales of the Automaton: The Big Birdocalypse, SPC-507, The Sacred Djehuti, Avian Anthology I, UMBRAL_MIGRATORY_SEQUENCE.txt, Avian Anthology II

Scenario: GD-Class Gestalt Dissolution Scenario
Hub: Skies Made Strange Hub
Used in: 1 SCPs, 5 Tales, 1 Other
Definition: By using amnestics to try and prevent the exposure of anomalies to the public, these end up creating their own anomalies themselves.
SCPs: SCP-3475
Tales and other articles: A Quiet Night, Into the Woods, Hello, Little Girl, It Takes Two, Children Will Listen, Birth of a New Day

Scenario: GR-Class Hostile Demiurge Event
Used in: 2 SCPs, 1 Tales, 3 Other
Definition: N/A
SCPs: SCP-3457, SCP-6672
Tales and other articles: Obskuracorps Memos Acquired in Operation BLACK ROPE, Archival Document -- HSA-008-Advent, A Man of Clay and Men Formerly Men, Unexplained Location UE-601616

Scenario: ΔW-class eclipse-of-consciousness scenario
Hub: The Magicifient Squelching Blunderbuggers Hub
Used in: 2 SCPs, 2 Tales, 0 Other
Definition: N/A
SCPs: SCP-1798, SCP-3547
Tales and other articles: The Slumbering Prince, The Long Game

Scenario: YN-Class "Ragnarok" End-of-Knowledge Scenario
Hub: Ragnarok Hub
Used in: 2 SCPs, 3 Tales, 0 Other
Definition: N/A
Alternative titles: N/A
SCPs: SCP-3488, SCP-3378
Tales and other articles: 0 Texts Found, The Curious Incident of the Contradictory Crocodile, Ragnarok

Scenario: The Threat
Hub: Project Palisade Hub
Used in: 3 SCPs, 5 Tales, 1 Other
Definition: A scenario involving The Threat, or THE WORM (yes it has to be written in allcaps, that's literally a thing in one of the articles); a multiversal entity beyond human comprehension that can instantly destroy universes, that may or may not be a discarded weapon from a war between even more incomprehensible entities. One particular iteration of the SCP foundation attempts to keep it away from their universe by making an uncountable number of parallel universes.
Alternative titles:
SCPs: SCP-3818, SCP-3591, WMDD's Proposal
Tales and other articles: UIU File: 2017-003, Good Fences Make Good Neighbors, Daffodils, T.K.O., Project Palisade Test Log, In The End

Scenario: ☿K-Class “World of Babel” Global-Incomprehension Scenario
Hub: Team Last Light Hub
Used in: 1 SCPs, 2 Tales, 2 Other
Definition: A antimemetic cognitohazard meant for use as a weapon is accidentally let loose, causing all who are affected to lose communicative abilities, with words spoken as random gibberish or out of place.
SCPs: SCP-3432
Tales and other articles: Not with a Whimper but with a Bang, KTE-6024-Blit-Nuntius, Project Proposal 2024-258, Pizzicato

Scenario: MH-Class "Large-Scale Aggressor Overrun" Scenario
Hub: War On All Fronts - Apocalypse / War On All Fronts - Anastasis
Used in: 4 SCPs, 6 Tales, 3 Other
Definition: Large amount of kaiju appear on earth and trample everything to death.
SCPs: SCP-3534, SCP-5514, SCP-5391, SCP-7714
Tales and other articles: Embracing The Angels, Project Sensuikan, The Kaiju Sea, A Storm More Foul, A Land Less Fair, GRANT REQUEST FOR THE CYBERNETIC MODIFICATION OF THE CORPSE OF THE CROCOTEUTHIS GIGANTIS, Awakening, Queen of the Monsters, Critter Profile: Cappi!, Reviviscence

Scenario: ARBH-Class "Insect Hell" Scenario
Hub: ARBH Class Hub, insect-hell tag
Used in: 2 SCPs, 2 Tales, 2 Other
Definition: A scenario where any species or populace of insects, by anomalous means, becomes a direct threat to the human race and its environment.
SCPs: SCP-3916, SCP-3879, SCP-4991
Tales and other articles: Critter Profile: Genghis!, ARBH-Class Debrief File, The Morality of Insects, The Last of LARPA, Zero Hour, Apologies and Redemption

Scenario: Öß-Class "Multi-Universal Amalgamation" Scenario
Used in: 5 SCPs, 3 Tales, 0 Other
Definition: Interaction of our universe with another.
SCPs: SCP-3582, SCP-5082, SCP-7548, SCP-CN-1997, SCP-042-INT
Tales and other articles: A Small Town in Arizona, Universal Collision, A Tale of Two Chugwaters

Scenarios that have only appeared in one article.

Scenarios or versions that only appear in Joke SCPs. (I'm looking at you, SCP-666½-J)

These are past lists where people have either tried to catalog K-Class scenarios or made up definitions for them. Feel free to add links!

Descriptive:
k-class-scenario tag
TVTropes EOTW page
thedeadlymoose's version (sandbox)
Kapitano's version (forum, 2016)

Speculative:
RhettSarlin and others (forum, 2010)
Russian K Scenario List, with both existing and potential scenarios.
<I know there is at least one (very old) A-Z list out there.>