Things that are frequently proposed in [[EpilepticTrees fan theories]] at a rate [[DeadUnicornTrope disproportionate to their occurrence in actual works of fiction]].

See Also: GrandUnifyingGuesses, PoisonOakEpilepticTrees
!!Theories common to general fandom
* EveryoneIsJesusInPurgatory:
** The cast died in the first episode and now they're all in Purgatory. Explicitly {{Jossed}} by the creators of ''Series/{{Lost}}'', among other writers. There was an infamous (false) rumor that this was how ''WesternAnimation/DungeonsAndDragons'' would end. After being explicitly {{Jossed}}, ''Series/{{Lost}}'' [[spoiler:actually ended this way, though its characters ended in Purgatory after they died, either during or after the series, rather than being DeadAllAlong]].
** There's also the one where character X is literally Jesus[=/=]God[=/=]Satan.
** Inversion: pick ''any'' character who died. [[SortingAlgorithmOfDeadness They aren't really dead]] / [[HesJustHiding they'll come back]].
* AllJustADream: This sometimes reflects either some fans' lack of faith in the writers or their lack of imagination; revealing that the whole story was a dream as a DeusExMachina has been a DeadHorseTrope for quite a while. Variations of this include:
** The hero is insane and delusional, [[CuckooNest and the entire story is his hallucination in an]] [[BedlamHouse asylum]].
** DyingDream is a very commonly speculated form, especially if the series starts with a near-fatal accident.
** The Tommyverse is well-known outside of TV Tropes. Essentially Six Degrees of ''Series/StElsewhere'' it postulates that every show that has ever crossed-over with ''St. Elsewhere'' exists in a shared universe wherein everything takes place entirely within the mind of autistic child Tommy Westphall, and the shows that crossed over with them, and so-on. This ultimately leads to a staggering number of television shows stretching from ''Series/TheXFiles'' to ''Series/ArrestedDevelopment''. On the other end of the spectrum it has sparked some fascinating (and pretentious!) discussions about the nature of intertextuality, metafiction, AsHimself, and other such post-modern concepts.
* LukeIAmYourFather. A legitimate trope, but fans take it way too far, especially with their tendency to assume that the BigBad is the father of TheHero, even when there is obvious evidence against it. This is probably influenced by the [[AllPsychologyIsFreudian widespread belief]] that Freud was right and that all conflicts can be reduced to [[OedipusComplex Oedipus]] CallingTheOldManOut.
* The BigBad is actually a pawn of the [[TheManBehindTheMan real Big Bad]], who is [[TheDogWasTheMastermind the character you would least suspect]] (for example, the [[RidiculouslyCuteCritter ridiculously cute]] NonHumanSidekick).
* The story is [[LiteraryAgentHypothesis actually being told]] by Character X, who may be an UnreliableNarrator. If the story ''actually is'' being narrated by one of its characters, [[UnreliableNarrator they can't be trusted]]; if the story ''admits'' they can't be trusted, [[SerialEscalation they're lying about different things than are implied]].
* The [[VillainProtagonist protagonist is the villain]].
* The protagonist is fighting on the wrong side. The [[GovernmentAgencyOfFiction agency]] they work for is secretly working for the enemies, or has a [[GovernmentConspiracy conspiracy]] going.
* The protagonist is fighting on the wrong side, because the "evil" characters are actually in the right and he/she is too blind or prejudiced to notice.
* Character X is a mole or traitor who will FaceHeelTurn. Alternatively, villainous Character Y is working for the heroes or will make a HeelFaceTurn. It used to be less common for a villain to receive enough development to make this one plausible ''unless'' it was bound to happen; these days, more creators are interested in humanizing the opposition, but that doesn't stop audiences from speculating.
* Any fantasy setting is often presumed to be EarthAllAlong either far in the future or far in the past, the epileptic trees even covering up cases where the dates are explicitly stated through an Unreliable Narrator. For stories that take place in a ConstructedWorld (which isn't supposed to have anything to do with our world): Show X takes place AfterTheEnd, or else in the distant past and two of the characters are [[AdamAndEvePlot Adam and Eve.]]
* Character X and Y share the same last name, therefore are related. This one might fly in a world with MinimalistCast -- but the closer you get to LoadsAndLoadsOfCharacters, the less likely it is. Unless, of course, your name is Creator/CharlesDickens.
* Any "Character X and Character Y are the same person" theories qualify, even when there's no clear reason for one or the other character to change his identity and they don't look anything alike. (''Lost'' gets this a lot, too). By extension, Character X is actually a ShapeShifter or BodySnatcher pretending to be Character X (in universes where they exist).
* Any given pair of characters who played a big role in the backstory and then vanished (or one such character and a current character with a mysterious past) will have a theory postulating that they're the same person, usually latching onto minor details in both stories to "prove" it. (Granted, this is more likely than a lot of these theories to be true.)
* Show X is set in the same universe as Show Y.
** Inversion: The spin-off is not really set in the same universe as the original.
** Or sometimes: The spinoff IS set in the same universe as the original
* The entire story is an AuthorTract regardless of WordOfGod. Common topics include sexuality, religion, politics, nukes or drugs.
* The Future is actually in the past, and vice versa.
* Each character represents one of the SevenDeadlySins.
!!Theories common to Wiki/TVTropes fandom
* WMG/TimeLord (that a certain character is a Time Lord from ''Series/DoctorWho'', especially any Time Traveller in the history of everything ever.)
** The suggestion that X character is LightNovel/HaruhiSuzumiya (especially any RealityWarper or TheOmnipotent or any protagonist in the history of everything ever), is another epileptic tree specific to TV Tropes.
** And the idea that character X is a [[TabletopGame/GeniusTheTransgression Genius]] is becoming popular as well. In a similar vein, the idea that character X is a [[Webcomic/GirlGenius Spark]].
** Every once in a while this actually makes sense: Check out the WMG for ''Anime/{{FLCL}}'' for a pretty good example.
* Series X is just a hallucination taking place during [[Anime/NeonGenesisEvangelion Instrumentality]].
* Any ManipulativeBastard or TricksterArchetype is [[Creator/HPLovecraft Nyarlathotep]].
* [[DoppelgangerCrossover Every character with the same actor/voice actor/]][[NamesTheSame name as a character from another franchise is actually that other character.]] (Tongue in cheek, usually.) Subverted in ''Series/{{Scrubs}}'': J.D. and Turk recognize The Janitor while watching The Fugitive. Neil Flynn (who plays The Janitor) actually had a minor role in The Fugitive. In the Scrubs universe, it was The Janitor himself who played the part.
* Any FanFic which has gained fame for being poorly written is a TrollFic. Which is usually true, but that's not the point.
* Something awesome is powered by [[Anime/TengenToppaGurrenLagann Spiral Energy]].