Grandfather Paradox: Difference between revisions

{{trope}}

'''Fry''': "I did do the nasty in the pasty!"|[[Futurama]].}}

 

If you kill your grandfather or destroy the time machine in the past, you should [[Ret-Gone|never have been born]] or never been able to travel into the past in the first place. If you kill the evil overlord while he's a child, [[Hitler's Time Travel Exemption Act|you shouldn't have any reason to travel into the past to kill him]], since in the changed present he was killed before he [[Doomed Hometown|destroyed your village]]. So killing your grandfather causes you to not exist to kill him. Which means he survives. Which means you ''do'' exist and proceed to kill him. [[Logic Bomb|And so on]].

 

 

If the universe runs on [[Stable Time Loop]], this type of paradox is impossible. Since all changes that [[Time Travel Tense Trouble|will have been going to happen]] "already" happened, you can't cause a change that will negate itself.

 

{{examples}}

== Film ==

* The plot of the first ''[[Back to The Future]]'' may be the most well known example, even though it's A. not Marty's ''grand''father it involves and B. he doesn't kill him, but rather accidentally {{spoiler|takes his place as his mother's object of affection}}. The rest of the movie has Marty trying to correct things before he's erased from existence.

** Though within the semi-canon/non-canon of the Telltale ''Back to the Future'' game, Marty does encounter his paternal grandfather and affects his own existence in time.

 

== Literature ==

** In ''Door into Summer'', this is boiled down to the time-traveler protagonist waiting just outside of a room where he also is prior to his time-traveling activities, and briefly wondering what would happen if he ran in and slashed his counterpart's throat. He doesn't do it, of course, because that would be stupid and accomplish nothing, but he notes in present tense that he ''still'' hasn't figured it out.

* The [[Charles Stross]] novella ''Palimpsest'' has a twist: killing your own grandfather is the initiation rite for the [[Time Police]].

** The graduation ceremony is stepping back in time a few minutes and killing ''yourself''.

* Paradoxically inverted in "Grandpa", a short story by Edward M. Lerner. In it the protagonist, Professor Fitch, survives two assassination attempts by his grandson, and preempts a third by deciding not to have children.

* In ''[[Johnny and The Bomb]]'', Bigmac suggests going back in time to kill Hitler. Johnny warns him of the dangers should he accidentally kill his grandfather, but Bigmac says it's safe since his grandfather doesn't look anything like Hitler. (Fortunately, by the time they obtain actual time travel, he's forgotten the plan.) Then they fall victim to an actual grandfather paradox: {{spoiler|their time travel results in Wobbler's grandfather being killed in a World War II bombing}}.

* In one classic sci-fi story, the protagonist decides to try to commit suicide in a grand way by going back in time to shoot his grandfather. He does so. Nothing happens, so he turns the gun on himself. The narrative continues on to note that the sound of the gunshot does nothing to disturb his grandmother and his grandfather's best friend as she tells him to make sure he pulls out in time...

* [[Discussed Trope|Discussed]] in [[Stephen King]]'s ''[[11/22/63]]''.

That was a good question, so I just told him to go on. }}

** Though he initially hand-waves, King does answer the question implicitly: Nothing would happen to the traveler. People who go through the portal are 'out' of the timestream and thus not eliminated as a result of their actions.

* Happens literally in René Barjavel novel ''Le voyageur imprudent'' written in 1943 (hence the first novel to enunciate the grandfather paradox) where the time-traveler (Pierre Saint-Menoux) tries to assassinate Napoleon Bonaparte before his rise to power: {{spoiler|at the last moment, a soldier jumps to take the bullet and save Bonaparte. This soldier is of course the time-traveler ancestor. The time-traveler is then wiped out from existence.}}

 

* For the [[Doctor Who|Time Lords]], Grandfather Paradox is an actual ''person'' who went back and, yes, killed his grandfather, which doomed him to a sort of undead temporal limbo. He's the Time Lord equivalent of the Bogeyman, and the splinter group/terrorist cult [[Faction Paradox]] considers him their spiritual leader, partly cause [[For the Evulz|it pisses off the Time Lords.]]

** We actually meet him. He's quite literally the [[Anthropomorphic Personification]] of [[Future Me Scares Me]] - he's ''everybody's'' evil future self.

** At one point, his appearance is described as eerily similar to the Ninth Doctor, which at that point would have been the Doctor's future self. In fact, the first time the Doctor encounters a [[Faction Paradox]] agent, the agent calls him "Gramps".

** Martha brings this up at the start of her first trip in the TARDIS.

"Well, then." }}

** In "Last of the Time Lords", The Master constructs a Paradox Machine specifically to evade the consequences of this paradox, {{spoiler|as his army of psychopathic laser balls happen to be the descendants of humans, from the end of the universe}}.

* Oh so inverted by the ''[[Lost]]'' episode "The Variable".

 

== Tabletop Games ==

* ''[[Genius: The Transgression]]'''s stance on the subject: "And yes, if you kill your own grandmother before your father is born, you will cease to exist. The universe, it turns out, doesn't care that much if your grandmother gets shot in the head and there's no shooter. You still go poof."

* The old ''[[Doctor Who]]'' RPG encourages [[GMs]] to be cruel to players who try this. One popular result is that, if you go back in time and point a gun at your grandfather, then the young version of your grandfather will leap out of the way, pull his own gun and shoot ''you'' dead. Paradox? What paradox?

 

== Video Games ==

* In ''[[Metal Gear Solid]] 3'', if you kill one of the bosses instead of just knocking him out, you get the "TIME PARADOX" [[Nonstandard Game Over]]. The reason is quite meta: you killed a boss which starred in a previous game, because ''3'' is a prequel to ''1'' and ''2'', which means you killed a boss in ''3'' which exists in ''1'' and ''2'', so with that boss dead he shouldn't exist in ''1'' and ''2'' anymore, so...

* Narrowly averted in ''[[The Legend of Zelda: Oracle of Seasons and Oracle of Ages|The Legend of Zelda: Oracle of Ages]]''; Ralph attempts to destroy his own ancestor Queen Ambi (who is possessed), ''knowing'' that it will remove him from existence. Subverted when she ends up kicking his ass instead.

* In ''[[Chrono Trigger]]'', Marle disappears from existence due to her being mistaken for her ancestor Queen Leene who was kidnapped at the time she landed in the past, and since they stopped looking for Leene thinking they had found her, she was killed, thus causing Marle to not exist. Fortunately Leene hasn't been killed ''yet'', so our heroes are able to go rescue her, which causes Marle to start existing again. While this is clearly a Grandmother paradox, everyone seems to remember that she existed at least long enough for her to cause herself to have never existed.

* In of ''[[Pokémon Mystery Dungeon]] Explorers Of Time/Darkness'' {{spoiler|The player character traveled back in time from a [[Bad Future]] to change the past. They lose their memory, so they don't know that, or that they knew full well what would happen to them if they did. In the 11th hour, they discover that changing the future will erase everyone from the future from existence, including themselves. They decide to change the past anyway, but don't have the heart to tell their partner what will happen. When the time finally comes, they say [[Tear Jerker|one last goodbye and fade out of existence]]. Everyone remembers them, including their heartbroken partner. Thankfully, Dialga, the god of time, sees this and, because of the [[Heroic Sacrifice]] on the part of the player, reward them by bringing them back to life. In the sequel, it's revealed that Arceus did that same for their friends still in the future (and Dusknoir, who performed a [[Heel Face Turn]]) for helping prevent the past from being altered again.}}

 

== Web Comics ==

 

== Web Original ==

* A [[Newgrounds]] cartoon "Grandbunny Paradox" made fun of this. It featured a bunny and a stick figure. The bunny went back in time to kill his grandmother and finds himself turned into a sheep, because his grandfather married a sheep instead of a bunny. The stick figure decides to do the same and kills his grandmother only to find himself turned into a tomato. He doesn't like being a tomato so he goes back and shoots the guy who sold him the gun to kill his grandmother...only to find himself now holding grenades.

 

== Western Animation ==

* In an episode of ''[[Futurama]]'', Fry goes back to Roswell in 1947 and accidentally gets his grandfather killed in an atomic blast [[Defied Trope|while trying to avert this trope.]] He doesn't stop existing because he ''also'' ends up doing his grandmother, becoming his own grandfather. Or, as he put it, "I did the nasty in the pasty." {{spoiler|This becomes a key plot point in later episodes, as this event caused him to have brain damage that made him immune to a number of things.}}

* In ''[[The Adventures of Sonic the Hedgehog]]'', one episode in the four-episode arc about the Chaos Emeralds starts with Sonic foiling a plot by Robotnik to prevent his ancestors from marrying and thus eliminate Sonic from the timeline. Sonic succeeds in sending Robotnik packing, but then '''causes the paradox himself''' by ordering a chili dog from his maternal ancestor, causing his paternal ancestor to become impatient waiting to be served and leave. After Sonic disappears, Tails solves the paradox in about a minute by forcing the meeting to happen.

 

{{reflist}}

[[Category:Time Travel Tropes]]