Time Travel



"Time travel is theoretically impossible, but I wouldn't want to give it up as a plot gimmick."

- Isaac Asimov

"(For related tropes, see Time Travel Tropes)"

A time travel story can simply use time travel as a vehicle to get the hero to the Adventure Towns, or the Phlebotinum involved can be a key plot driver. No matter what story type the hero is going to need a Time Machine or Time Master to get around. Time Travel stories seem to fall into several categories:


 * 1) You Can't Fight Fate: Characters go to the future! They must get back to their own time and prevent the future from going horribly horribly wrong. Sometimes, they can't, in which case it's You Cannot Change the Future or a Stable Time Loop (see below).
 * 2) Set Right What Once Went Wrong: Characters go to the past! Again, this is usually to "fix" the future- that is, the characters' "present." Often this involves correcting a Temporal Paradox. Remember, Hitler has Time Travel Exemption.
 * 3) Make Wrong What Once Went Right: Characters go to the past! But... not to fix the present or future. They want to change the events in some way, to favor themselves or their employer. Generally bad things ensue.
 * 4) Terminator Twosome: Both of the above at once; a villain goes back to change the future in their favor, and a hero follows to put a stop to it.
 * 5) Stable Time Loop: Characters go to the past! And in the past, they turn out to be responsible for the events that led to their "present." In other words, You Already Changed the Past. This is similar to You Can't Fight Fate, but in the present instead of the future.
 * 6) Includes cases of the Wayback Trip.
 * 7) Temporal Paradox: Now it gets complicated...
 * 8) Characters go to the past! In the past, they change history: If they do so by accident, it well may end the story with a Karmic Twist Ending; alternately, it will set the real plot in motion by requiring the characters to Set Right What Once Went Wrong.
 * 9) On the other hand, they may have set out to change history intentionally, so that the events that create their future/present—and, thus, the conditions that prompted them to go back in time—never happened, basically the same set up as above, but without the initial "accident."
 * 10) Characters go to the future! Upon returning to the past, they are able to fight fate and prevent the events of the future (seeing which prompted them to try to prevent the events of the future in the first place) from occurring.
 * 11) Reset Button: The characters go through a world of crap, or somebody "changes history", and they resort to time travel to fix it. If they succeed, the time-line fixes itself and the characters awaken having no knowledge that anything was ever different. Occasionally, only the time-travelers remember—at least, the ones who were alive at the point of fix. If they don't succeed, the series has just received a Retool or Story Reset.
 * 12) Trapped in the Past: The characters are stuck in another time with no way of return and must choose between quietly living out their lives without changing history or working to change the world to their (and the natives') benefit. You'd be amazed how few people seem to pick the first option.
 * 13) Alternate Timeline: The characters time-travel has split their universe in twain. There's the universe they're in (that's they've "changed") and the universe they're not in. (the "old" universe that wasn't changed.)

No matter what the variation, if there's a scientist or scholar in the group, he'll be giving warnings about the Temporal Paradox risk. And every trip risks an encounter with the Butterfly of Doom or accidentally leaving behind a Timeline-Altering MacGuffin.

Time travel is also a very large source of Mind Screws. This is because the human mind is used to one-way time; cause and effect requires it. In two-way time, the entire human logic system has to be thrown out.

Note that only the Stable Time Loop and Alternate Universe (when done properly, i.e. you can never get back to the first universe) resolutions are the only ones logically consistent with typical ideas of causality so stories wishing to be more "realistic" should favor these.

Stories not wishing to be "realistic" of course can just ignore the whole Temporal Paradox thing for some reason. Maybe the time travelers have Ripple-Effect-Proof Memory or otherwise get to ignore their own pasts making them immune to changes in the timeline. Afterall its not like we actually know what will happen right, right?

Even less sensibly time travel may run on San Dimas Time or display a Groundhog Day Loop.

When the same universe can't keep its own rules for Time Travel straight... it's more like a big ball of wibbly-wobbly... timey-wimey... stuff.

See also Temporal Mutability for the very tricky problem of how (or even if) you can change the future or the past.

See also Meanwhile in the Future, What Year Is This? and this Wikipedia entry.

Anime and Manga

 * In Simoun, time travel requires the successful completion of the Emerald Ri Maajon, an extremely dangerous maneuver that can only be accomplished by a pair of the most skillful pilots with a powerful emotional bond with each other. Failed attempts are generally fatal, with explosive consequences.

Comics

 * In Universal War One, scientists build a space station that accidentally opens a wormhole, allowing limited time travel.

Film

 * In Donnie Darko people in the future will be able to mess with the past without leaving the future via machine. Such meddling causes alternate universes which need destroyed or they'll erase the future-people's universe.
 * In Back to The Future, you needed a way to generate 1.21 gigawatts of power, such as nuclear fuel or a lightning strike, and a ground speed of 88 miles per hour.
 * In the Terminator series, only organic things could be sent through time. No weapons or clothes or anything but the time traveller.
 * Rather conveniently forgotten by T2. The only thing that allowed the original T-800 model 101 back through time was the fact it was a shell surrounded by living tissue. It was, to quote Kyle Reese, "something about the field generated by a living organism'. Nothing dead will go." Therefore how exactly the T-1000 which was liquid metal managed to travel through is just, well, kinda unexplained.
 * In Jean Claude Van Damme's Time Cop, there's a federal agency responsible for going after people who attempt to go back in time. He winds up
 * Star Trek 4, 7, 8 and 11 all use time travel as a device, by a different method each time.
 * This website lists almost every single Time Travel movie ever made, from 1921's A Connecticut Yankee in King Arthur's Court up to 2009's Star Trek. http://cvil.wustl.edu/~gary/SF/time-movies.html
 * Frequently Asked Questions About Time Travel has several of the above mentioned categories (notably Set Right What Once Went Wrong taken to Knight Templar extremes, as  as discusses the rest.
 * In 12 Monkeys, James Cole travels to the past several times, to find a sample of The Virus before it become The Plague.
 * In The Butterfly Effect, the protagonist has mysterious periods of blacking out. As a young kid, he starts writing a journal describing his feelings. Years later, he finds out when he reads the journal before a blackout, he goes back in time to the period of the blackout. He quickly finds his time travel has a type of Psychic Nosebleed limitation.

Literature

 * In Millennium the world is badly contaminated, so the government sends people to go backward in time, capturing everyone who was on a transport (plane, train, or ship) where all of the people on the transport were killed, or an event (a war, an attack, an explosion) where everyone in the area dies, and replacing them with cloned dead bodies so as not to change history. The problem is that once anyone goes to a particular time, no one can ever go back to anywhere during that period, the time period - an hour, two hours, whatever - is blacked out and unreachable. Visit a plane flying over the Atlantic Ocean for an hour and you can't go to Paris, New York or Antarctica at the same time later on.

Live Action Television

 * In Seven Days, the hero was the only one who could work the device reliably, and he could only go back seven days at a time.
 * In Time Trax, the method varied, but the rules were that you could only travel between two set time periods (The Present and The Future), and more than two trips in a lifetime are lethal.
 * In the original Star Trek, time travel required either a dangerous and complicated slingshot maneuver or a precision jump into the Donut of Forever or Mr. Atoz's Atavachron, but these days Trek characters can travel through time by spilling coffee on their tricorder. (Which is probably why Star Fleet now has a department of time travel cops staffed entirely by grim-jawed Men in Black, as seen in DS9.)
 * Note that this isn't just a Plot Tumor (though it is one of those too)- time travel really is getting much easier in-universe as technology advances. By the end of the 24th century, it's shown, Starfleet's temporal function is beginning to overtake its spacial one. This is a large part of why they went to Prequels after Voyager. Of course, the Plot Tumor in question being TIME TRAVEL, this helped not at all.
 * Time Travel is such an amusingly big thing in Star Trek that, in Star Trek Online, Section 31 are revealed to have a star system set up specifically for pulling off the "slingshot around a star" stunt with precise calibration.
 * Doctor Who is all about time travel.

Tabletop Games

 * In the Role-Playing Game Feng Shui, a region of cross-time 'space' called the Netherworld allows characters to move between four different points in history (69 AD, 1850 AD, 1996 AD and 2056 AD). These junctures are fixed with relation to each other, treating the start of the campaign as zero-hour for all of them. So, if you enter the Netherworld in 1996, travel back to 69 AD, stay for six months and then return to '96, it will be six months later there, as well. A second use of Phlebotinum states that only people who control powerful feng shui sites can actually change the future by changing the past; everyone else just sees history work itself around the change.
 * In the card game Chrononauts, the players are time travelers from various alternate futures, and are trying to change the timeline to match their own timeline's version of the "past" so that they can finally go home. Since all the alternate futures have conflicting versions of "history," and many of those conflicting versions require a specific outcome to World War II (Hitler was assassinated early and WW 2 was Japan vs. America, Hitler lived and D-Day failed so that Germany won WW 2, and a couple other variants), Hitler's Time Travel Exemption Act gets a real workout. There's an alternate victory condition in which players have to collect certain combinations of Mac Guffins of questionable historical importance, but that's for material gain, not timeline shenanigans. A third victory condition is to get hired by the local Time Police after fixing enough of other people's paradoxes.
 * Continuum is a Tabletop RPG entirely about Time Travel. Read its page for the details; further information is not available here.
 * Time and Temp is another Tabletop RPG entirely about Time Travel, using office temps (temps, get it?) as field agents because (as unimportant shlubs) their lives are least likely to suffer a reality-ending paradox due to their own past actions. What Could Possibly Go Wrong??

Web Comics

 * Narbonic: the 'Dave Davenport is Unstuck in Time' arc codified the rules, and future story arcs used the same rules. Fiddling around puts you in an Alternate Timeline. To move through time requires all the eneregy of an entire universe, thus utterly destroying an alternate universe/timeline in the process. Since you are in an Alternate Timeline, you can indeed change the future or the past. Dave is able to stop smoking by never having started. He is also able to give his past self information
 * Sluggy Freelance: There are many, many instances of Time Travel, the consequences thereof, and the fools who pursue it in The SluggyVerse.
 * Dr. Irving Schlock
 * The Time Czar
 * Times Like This: The whole premise of the comic.
 * The Time Czar
 * Times Like This: The whole premise of the comic.

Video Games

 * In the "Timeline" mod series for the original Half Life, rogue scientists from Black Mesa have figured out how to use the dimensional portals to travel through time. Gordon Freeman is elisted to...
 * Episode 1: Stop the scientists, who have given the time travel technology to Nazi scientists, to keep them from controlling key moments in history and changing the timeline... then when that doesn't work, going back in time again to make sure the nuking of New York never happened...
 * Episode 2: Sideslip to an alternate Earth where Gordon Freeman failed to stop the Xen invasion and try to Set Right What Already Went Wrong, only to find Those Wacky Nazis meddling in that dimension as well...
 * Episode 3: Go back to before the Black Mesa Incident, to try to stop the acquisition of theXen crystals that started the whole mess in the first place.

Western Animation

 * In Time Squad the characters have to constantly go back in time in order to stop goofups in the timeline (because time is like a rope and as it grows it becomes frayed). Hilarity Ensues when they encounter historical figures doing crazy things, such as Eli Whitney creating flesh-eating robots instead of the cotton gin, Ludwig von Beethoven becoming a wrestler instead of a composer, or George Bush thinking that the answer to all of the country's problems is a giant ball of twine.

Anime and Manga

 * The Suzumiya Haruhi stories/anime feature time travelers, most notably Mikuru. It gets important in a major way in the novels, which also push Mikuru from being the Neutral Female somewhat.  The 7th novel also circles around it, this time with a Mikuru from a week in the future, setting off events to inspire the future inventor of time-travel and set off events necessary to bring about her organization. Like by nailing a can to the ground to send a man to hospital so that he can meet his future wife, or by dropping a turtle into freezing water to teach the inventor of time-travel something.
 * For everyone who has questions, I present you [[media:timeline.png|this]]. If it even helps. Careful of spoilers.
 * Soukou no Strain used the theory of general relativity to drive the plot. Sara's own motivations to become a Reasoner are to meet up with her brother, because if he returns from military service in space after a couple of years in his time, she'll be long dead in hers. Ralph's motivations are explained by his being able to go back hundreds of years using the same theory.
 * Zipang, where a JMSDF destroyer somehow ends up at the Battle of Midway. It's actually much more interesting that it sounds.
 * Tsubasa Reservoir Chronicle later turns out to have used this, having hidden it among a bushel of jaunts to alternate universes, or "countries". One "country" turned out to be the main characters' homeland in the past..
 * Pokémon 4 Ever features a Celebi that inadvertently brings with it to the present day when escaping from a hunter.
 * The Yu-Gi-Oh! film Bonds Beyond Time features Paradox, a time traveling villain who wishes to change the past, and Yusei goes through a time slip. During the course of the story,
 * In Mirai Nikki, its use is so incredibly spoileriffic details can't be given. Let's just say it's important.
 * In Puella Magi Madoka Magica, this turns out to be the main power of

Comics

 * PS238, especially the later issues. Includes several confusing stable time loops
 * Booster Gold is the current Time Travel comic at DC, exploring the difficulties of solidified time and the effects of the various crises on the time line, making it like "Wet Cement".
 * JSA has featured the modern Starman, a severe schizophrenic with powerful gravity controlling abilities. He claims, and it's probably true, that he is from a future Legion of Superheroes, future in terms of the Legion's comic too since he's an adult and the Legion in its comic is composed entirely of teenagers. Starman is also a dimensional traveler, who made his original appearance in Kingdom Come by helping Superman try and contain the villains and anti-heroes; apparently he can travel through time and the multiverse through a combination of his powers and a map that's written into his costume.
 * Prior to 1985 Superman could time travel under his own power but would arrive in the past completely invisible and intangible, unable to interact with the past in any way, avoiding the problems with this trope. After 1985, he was no longer powerful enough to time travel at all.
 * Not quite. He would be invisible and intangible only if he travelled to a period where he already existed, since he couldn't be in two places at the same, er, time. If he travelled to a time prior to his own birth, he was solid. However he still couldn't change the past.

Film

 * Planet of the Apes.
 * Primer.
 * Groundhog Day
 * Bill and Ted.

Literature

 * The concept of travelling forward in time can be found in several ancient stories:
 * In the ancient Indian epic Mahabharata, King Revaita travels to heaven to meet the creator Brahma and is shocked to learn that many ages have passed when he returns to Earth.
 * The Jewish religious scripture, the Talmud, mentions Honi HaM'agel going to sleep for 70 years and waking up to a world where his grandchildren have become grandparents and where all his friends and family are deceased.
 * In the 8th-century Japanese tale of Urashima Taro. Urashima Taro is a young fisherman who visits an undersea palace and stays there for three days. After returning home to his village, he finds himself three hundred years in the future, where he is long forgotten, his house in ruins, and his family long dead.
 * The concept of travelling backward in time is relatively more recent. The idea was hinted at in Samuel Madden's Memoirs of the Twentieth Century (1733), and told more explicitly in Alexander Veltman's Predki Kalimerosa: Aleksandr Filippovich Makedonskii (1836).
 * A Christmas Carol's (Charles Dickens, 1843) ghosts of Christmas past, Christmas present and Christmas yet to come allude to the concept of travel both backward and forward in time, but only as a passive observer.
 * The Time Machine (H. G. Wells, 1895) inspired 99% of the modern uses of the concept. The book used it to provide a present day frame story for a tour of the future.
 * Zits in Flight time travels continuously by going into different bodies.
 * Time and Again, and its sequel Time After Time by Jack Finney.
 * Dragonriders of Pern: The earlier books used the newly-(re)discovered time-traveling ability of the dragons for several plot points. After the Big One (Lessa bringing the lost Weyrs back through time with her) time travel was relegated to a Save The Day plot device.
 * Which had more to do with the detrimental effects of dragon-based time-slipping: first, simply making the jump required traveling through the sensory-deprivation hell that is "between" for extended periods far beyond the quick three-breaths referenced in early stories, and second being in two places at once had ever-increasing mental effects on the travelers in question...effects that were decidedly unhinging to the travelers and intensified drastically the closer they were spatially to an earlier incarnation. Lessa's jump some four hundred years into the past very nearly killed her from apoxia, and the one recorded time that an earlier version actually caught sight of a later time-traveling one (for a split second, and even that only as a shadow moving in darkness) left the earlier incarnation almost completely physically and mentally incapacitated for a good fifteen minutes.
 * A Tale of Time City by Diana Wynne Jones. Time City is "outside" normal time, using recycled time (hence very important/emotional moments get burned in and are seen as time ghosts both before and after the event). Time is divided into unstable eras to be visited with great caution (ours obviously) and stable eras that they trade information with. However, they only sell information about the (relative) past, no stock market sneak previews.
 * 1632 is all about this. Its the entire point of the series.
 * The various protagonists of Michael Moorcock's Jerry Cornelius stories time-travel more or less constantly - in fact with Jerry it's damn near involuntary.
 * Oswald Bastable is also subject to this kind of involuntary shifting between alternate histories.
 * Thursday Next features multiple versions of history within a single book, but only the reader and the (off-screen) timetravelers are aware of this fact.
 * In the novel Rant: An Oral Biography of Buster Casey,
 * The Time Scout series is built around an Accident that caused time portals to open up between random times and places. The stories cluster around people who happen to go places for various reasons.
 * Doomsday Book, among other books by Connie Willis, features time-travelling historians who visit the past via a "net".

Live Action Television

 * Doctor Who is normally a variant of Adventure Towns, as the Doctor firmly believes that the timeline should not be altered, although some stories are concerned with the Doctor trying to prevent somebody else from changing the timeline.
 * Though this only seems to apply when the audience know what history "should" be. The Doctor won't save Pompeii from burning or steer the Titanic clear of the iceberg, but will happily stop a volcano erupting on the planet Tharg or a spaceship hitting an asteroid and exploding. The question "but what if the volcano on Tharg is *supposed* to erupt and kill everyone" is never asked. Bellisario's Maxim may apply here. The Doctor mentions in the new series that he can tell the difference between an event that can be changed and a fixed point in time which can't.
 * In fact, Doctor Who has generally been somewhat shy of actually using Time Travel as part of the plot, rather than merely a way of delivering the characters to the Adventure Town of the week.
 * Until the Steven Moffat era. Moffat's episodes are well-known for incorporating Time Travel or temporal paradoxes as an integral part of their plots, and the season arcs in his two years as executive producer have both focused on issues associated with the Timey-Wimey Ball.
 * Quantum Leap
 * Star Trek: Enterprise: One of its central premises was a "temporal cold war", in which bandits are going back in time and messing with the timeline. The rules and limitations of time travel are never explained to anyone at any time, so the writers had a license to Ass Pull.
 * The Time Tunnel.
 * Voyagers - this was the entire premise. The 'Voyagers' were charged to Set Right What Once Went Wrong - they used one gadget, the Omni (which looked rather like a large gold pocketwatch), both to travel and to figure out what was wrong and how to set it right.
 * Kamen Rider Kabuto heavily featured a Worm ability called 'Clock-Up' (reproduced artificially by the Zecters used by the Riders) which allowed the user to warp the flow of time and dramatically increase their speed. Later, Tendou gained the ability of Hyper Clock-Up, which allowed him to turn back time when the plot demanded, but with the occasional habit of throwing him into nearby sub-dimensions.
 * Kamen Rider Den-O features a superhero that travels back through time on a passenger train, DenLiner. Fairly early on, it is established that he is a "singularity point" a person who is completely immune to changes in the time stream and thus especially qualified to battle time-traveling Monsters of the Week. Why the OTHER singularity point handy,, doesn't do the job remains unexplained.
 * Heroes has the character Hiro, his time travelling basically set off the whole first series in an attempt to change the future, it's a lot harder than you imagine, apparently. Also in the second series, he travels back in time and creates the character he heard in his bedtime stories. Peter also is prone to time travel but less often.
 * As the titles indicate, Mirai Sentai Timeranger and Power Rangers Time Force feature this; they're about Time Police squads from the year 3000 who have chased a prisonful of escaped inmates to 2000 (Timeranger) / 2001 (Time Force).
 * Lost from season 3 on, but especially in season 5. In Lost time travel nothing can be changed and everything is one huge Stable Time Loop. Note that the first person who claimed that time could be changed was once he actually tried to.
 * Prehistoric Park: A group of people (lead by Nigel Marven) set up a safari park filled with prehistoric creatures by traveling to the past and capture the creatures themselves. The time traveling device itself is never discussed in depth but it is what made the whole thing possible.

Video Games

 * Achron takes the prime mention here - a Real Time Strategy game whose plot and gameplay are both mostly about time travel.
 * In The Elder Scrolls: Oblivion a book tells the story of a famous battle in which magical time-altering storms were coming on an area and a local nation which knew their workings used them to deploy troops favorably. So they got hours of killing in where their soldiers outnumbered the enemy, had men in place to sack castles when hours turned to days, etc.
 * Final Fantasy XI uses this in Wings of The Goddess to travel 20 years ago to the Crystal War, one of the largest wars in Vana'deil's history.
 * Chrono Trigger.
 * Tales of Phantasia.
 * The central plot of The Journeyman Project trilogy hinges on time travel, due to the existence of a government agency specifically created to prevent the alteration of history.
 * Dark Cloud 2 (a.k.a. Dark Chronicle), both with objects the main characters carried and a flying, time travelling Cool Train that seems awfully familiar.
 * Super Robot Wars Reversal has this as the main plot, the main characters got sent off to the past due to the encounter with the Big Bad and had to decide whether to let the future stay stable, or change it by modifying the past (they picked the second).
 * The Ecco the Dolphin series is all about time travel. The second game's plot even centres around the time travelling in the first game screwing up the time stream.
 * Legacy of Kain: big part of the plot. Especially in Defiance where point of view jumps between two protagonists in different eras, culminating in them both travelling to a same era to finally meet.
 * The driving force behind the plot of Pokémon Mystery Dungeon Explorers is that the god of time is slowly losing his marbles, and time is screwing up royally as a result.
 * Shadow Hearts: Covenant.
 * Prince of Persia. The Sands of Time trilogy features 6–10 seconds of time travel as the primary gameplay gimmick. The entire point of the second game is to Set Right What Once Went Wrong thus pushing your character's Reset Button. There's even a moment in the third game wherein the prince decides not to use the reset button again and man up to his mistakes.
 * Day of the Tentacle
 * Warriors Orochi 3. A monstrous eight-headed beast called the Hydra kills most of the heroes. The few remaining survivors are aided by Kaguya, the moon princess from Tale of the Bamboo Cutter, who uses her ability to travel through time to rescue the heroes who died in the battle with the Hydra.
 * Sam and Max: Chariots of the Dogs
 * Sonic the Hedgehog '06 employed this trope annoyingly, to the degree that after a series of confusing time-jumps (one of which is to undo sonic dying), a small fire is blown out, thus erasing the whole sequence of events, time jumps and all. This renders it effectively an "It was all a dream" scenario.
 * In Darkfall 2: Lights Out, the protagonist stumbles into one of several time portals, and must move repeatedly back and forth in time to figure out what's happening and return to his own era.
 * The changing-the-past equivalent was used thrice in Ratchet and Clank: A Crack in Time, the first time to save Orvus from Dr. Nefarious, the second to defend Zanifar from the Agorians, and the third to The main plot also centers around using the Great Clock to travel back to prevent larger incidents. In Nefarious' case, he wants to wrong all the rights in the universe. For Ratchet and Azimuth, it's going back to prevent the Lombaxes' banishment.
 * Radiant Historia not only deals with time travel, but parallel universes caused by making different choices at certain points in time.
 * Time Travel is used several times in the Command & Conquer: Red Alert series by various factions, trying to improve their fortunes (generally by removing key enemy figures, such as Hitler or Einstein). It never goes well; the first game kicks off when Hitler gets cut from history, leading to a WWII between the Allies and Stalin, while in the third, the various time-travel shenanigans throughout the series have accidentally turned tiny backwater Japan into the Empire of the Rising Sun, a(nother) superpower bent on world domination. Hilariously, the Emperor believes in the "inevitability of destiny", and has a serious Villainous Breakdown when he discovers the truth behind the Empire's existence.
 * Magical Girl Lyrical Nanoha A's Portable: The Gears of Destiny features a Time Machine Lost Logia discovered by a brilliant scientist who is trying to restore a dying world. The scientist, being the well-meaning and sane kind, decides not to use it since it for his purposes since that would cause too many complications to the timestream. Unfortunately, her daughter Kyrie, who doesn't want her aging father to die without succeeding in his life's project, decides to use it to retrieve an Applied Phlebotinum that only existed at one point of a specific timeline, kicking off the plot of the game.

Web Comics

 * Earthsong features a particularly head-spinning variant that doesn't actually CHANGE TIME AT ALL.
 * Dresden Codak has a major plot arch which revolves around time travelers from the future entering  the present.
 * Homestuck incorporates a lot of Time Travel in its plot points, especially with the Midnight Crew intermission, where every single member of The Felt had a special ability related to manipulating time or alternate timelines. Within the main story, Dave (as the Knight of Time) has the ability to accelerate or reverse time around him. Alternate Future Dave becomes a minor character,
 * Bob and George. Oh, lord, Bob and George. One of the recurring catchphrases shared by many characters is "I hate time travel". George even suffers a nervous breakdown when faced with having to use it.
 * The Adventures of Dr. McNinja features time travel (as well as dimensional travel) in several arcs, including "Doc Gets Rad" ( gets defeated by being trapped in a Stable Time Loop), "Army of One" (In a Flash Back, a time-travelling tries briefly to stop Doc from being cloned by Ben Franklin II), and "Space Savers" (Yet another  travels back in time [and into another universe] to stop a space dinosaur invasion). Since the comic works on Rule of Cool, the precise rules for how all this fits together are never clearly established.
 * The Dreamer features an odd case of time travel. Whenever the heroine falls asleep, she is transported to 18th century America in the middle of the American Revolution.
 * Kingdom Hearts 3D adds time travel to the list of twists surrounding Xehanort, the series' main villain. As a result, his egomania and knack for swapping bodies and identities has reached its logical conclusions - the different incarnations are acting as Big Bad, Co-Dragons and The Heavy all at the same time.

Western Animation
"Narrator: But where is he going, Professor? Professor: I don't know. We take pot luck."
 * In Hanna-Barbera's video series The Greatest Adventure Stories from the Bible, three young adult archaeologists find a door that takes them back to Biblical times. (Good thing the portal has random entrances and exits scattered through time, allowing one to cover thousands of years of Biblical history in a few weeks.)
 * Similarly the twin anime series Superbook and The Flying House are built around regular time travel into stories from the bible.
 * Time Squad involves time travel in almost every episode, as its name implies.
 * Meet the Robinsons.
 * little known film Our Friend, Martin in which teens visit Martin Luther King at several points in his life and then bring him to their time, only to find doing so changes their timeline to one where his civil rights speeches and protests never happened (since he wasn't there to make them because he was in the future) so he must return home to restore the original timeline.
 * Quasi at the Quackadero is set at an amusement park where time travel is exploited.
 * The WABAC Machine sends Mr. Peabody and Sherman back to assist historical figures in their quest for immortality.
 * The Powerpuff Girls episode "Speed Demon" has the girls racing for home so fast they go fifty years into the future and see that the world has been subjugated by their arch-foe Him because they weren't around to stop him as they went through time.
 * In the Al Brodax Popeye cartoons, Professor O.G. Wottashnozzle uses Popeye as a guinea pig for his time machine, which posits him and the others as historical figures.

Anime and Manga

 * Time travel is specifically taboo in the Sailor Moon universe, and it's the job of Sailor Pluto to guard the gate of time and make sure no one uses it. That said, The sailor soldiers (Chibi-usa especially) make occasional trips between the 20th and 30th centuries.
 * The Android Saga from Dragonball Z is kicked off by the arrival of Trunks, a Future Badass who owns both Frieza and King Cold when they come to Earth to seek revenge on Goku before revealing himself to be the son of Vegeta and Bulma. He's traveled back in time because the future he came from is a Bad Future where human civilization has been destroyed by the Androids and he wants to prevent that future from coming to pass by making sure that Goku doesn't die from the heart disease that he picked up on Planet Yadrat. He's only half successful because while Goku does survive the heart disease, he's out of action for the good part of the saga, leaving Trunks and the rest of the Z team to battle the Androids. Then an even more dangerous villain arrives from a third timeline...
 * Yu-Gi-Oh! 5D's gives us the Infinity Device, which is capable of creating wormholes, useable for time travel. Illiaster intends to use the device to further their own schemes in.
 * In the Recap Episode of UFO Ultramaiden Valkyrie, Princess Laine gains the ability though time. She uses this ability throughout the rest of series. Mostly to hangout with herself.

Literature

 * The Hitchhiker's Guide to the Galaxy explains that there can't be any temporal paradoxes, because "all the important changes have already been made."
 * On the other hand it also mentions that because of impatient building contractors with time machines, the great Cathedral of Chalesm was replaced by another building before it was ever built, thus making any pictures of it very, very valuable, blank, or both.
 * In The Restaurant at the End of the Universe, Marvin the Paranoid Android is abandoned for most of the lifespan of the universe due to time travel. It is later stated that, due to his various time travel incidents, Marvin is several times older than the Universe itself.
 * The novelization of the 1998 Merlin series implies that Lancelot came from a place in the future, or in a possible future, and was brought from it to the time of Arthur, by Merlin, to act as the king's champion. When Merlin first arrives there, they seem to have heard of him, though they never bring up what the history of their land says about it all.
 * A Simple Survey has a short story where time travel is a widespread technology, albeit with significant limitations. The time traveller can't physically go back in time - instead, they can influence objects in a manner similar to a poltergeist. Not all of history is accessible, either. Only certain specific periods of time can be used, which are called "time lodes". Any given time lode can only be accessed once, so they are a limited resource. Another problem is that repeated use of time travel has made time itself less malleable, so that it's difficult to even influence anything in the few remaining time lodes.

Live Action Television

 * Lois and Clark had a few time travel episodes that included Time Machine author H. G. Wells.
 * Charmed had a central character who was from The Horrible Future.
 * Stargate SG-1 had several episodes involving time travel--"1969" when they travel back to said year due to Stargate mishaps, Groundhog Day Loop episode "Window of Opportunity", "2010" showing a possible future where everyone is sterilized, "It's Good To Be King" with prophecies from the Ancient time-travelling puddle jumper, season-8 finale "Moebius" involving the same jumper and a twisted Time Loop (to be expected given the name), and season 10 Grand Finale "Unending".
 * In Stargate there are three methods for time travel:
 * 1. Travelling through a wormhole that intersects with a solar flare causing the wormhole's course to alter sending the matter in transit back to the either the dialing Stargate, the destination Stargate or another Stargate altogether.
 * 2. Using a time machine built by the Ancients to either get an area of a galaxy stuck in an ever repeating loop, or a Puddle Jumper with a time machine component that can only jump in jumps of 100+
 * 3. Although not time travel persay, but, Asgard time dilation fields can be reversed to the time when the field was created.
 * In season 2 of Roswell, Max travels back in time after everyone but he and Liz dies, in order to persuade past-Liz to break up with past-Max and make him get together with Tess. It's very silly and involves mariachis.
 * Power Rangers occasionally calls on this, even outside the Time Force season. Mighty Morphin' had a couple of trips back to the wild west era and the quest for the Zeo Crystals. SPD team had two separate time travel eps so they and the Dino Thunder Rangers could each visit the other team's home turf. Cam did the Kid From the Future thing on his quest to become Sixth Ranger, and Carter got the chance to repeat a day and save the lives of his teammates.
 * Babylon 5 called upon time travel in a few key episodes.
 * Lost hinted mildly at time disparity in season 2, flirted with time travel in season 3, and took the full plunge by the end of season 4.
 * Nick Arcade had a Time Travel board where the player (Mikey) moves between the past and the future of his own neighborhood.
 * Supernatural - Sufficiently powerful beings (e.g, angels) are capable of time travel, though it's not used often and changing the past was supposedly impossible until the Screw Destiny at the end of season five. In season six, Balthazar rewrites history by saving the Titanic; the incarnation of Fate, already pretty pissed at the main characters for putting her out of a job, draws the line at changing the past and coerces Castiel and Balthazar into restoring the timeline.

Video Games

 * In Fallout 2 there is a random encounter, which sends you back to the prequels vault 13, where you break the water chip. Thus making you responsible for the events at the beginning of Fallout 1.
 * One of the missions in Osu! Tatakae! Ouendan involves being called by Cleopatra in Ancient Egypt to cheer on her helping her workers to build a Pyramid in 10 days so she can use its magic to get more beautiful and greet her lover Marc Antony properly.
 * Likewise, in Elite Beat Agents, one of the missions involve travelling back in time (by purpose) to Florence in the 15th Century, to help Leonardo Da Vinci win the heart of Mona Lisa and eventually create his masterpiece of painting.
 * Three Zelda games use it as a core game mechanic: The Legend of Zelda Ocarina of Time has Link travel back and forth seven years, Majoras Mask has him travel through a Groundhog Day Loop, and Oracle Of Ages has him use a harp to travel 400 years to the past and back. The mechanics aren't exactly consistent; time travel in Ocarina of Time causes a timeline split, but seems to operate on a Stable Time Loop system in the Oracle of Ages. And let's not get started on the various ways the time travel mechanics of Majora's Mask might work.
 * The Legend of Zelda Skyward Sword heavily features this mechanic in the Lanayru area: By hitting Timeshift Stones, Link can return an area in a certain radius from the stone to how it was in the past, also reviving any creatures whose remains lie in the area. So basically you can travel through time by walking into or out of the area of effect.
 * Time travel also plays a substantial role in ; among other things,, and.
 * Ultima II: The main part of the game involves travelling between five time periods, Legends (no time), Pangea (9,000,000 BC), 1423 BC, 1990 AD, the Aftermath (2112 AD)
 * World of Warcraft features the Reset Button version of this in its Caverns of Time dungeons.
 * The Okami series has used 4 different methods of time travel over 2 games. The Spirit Gate, a time machine, demon magic, and literally cutting space and time.
 * Okami has you travel 100 years into the past, and relive the legend of how Nagi slew Orochi. The way it's set up makes it seem like The Legend of Nagi and Shiranui: The Abridged Series.
 * Okamiden forces you to travel through time to prevent Akuro from becoming perfect by Later, you need to summon your partners for the Boss Rush, and the way it's done is rather absurd even for a fantastic series like this.
 * In Kingdom Hearts II, Pete's sheer nostalgia for the good old days when he was just a boat captain somehow opens a portal into Disney Castle's past. Unfortunately, his actions weaken the Castle's protection in the present, allowing Maleficent and The Heartless to invade. Merlin conjures the protagonists a magic door that lets them follow Pete and enter "Timeless River", a level-wide homage to early Disney. Everything is Deliberately Monochrome, and the present-day characters (except present Pete, who actually interacts with his past self) find themselves in their old outfits. Time travel isn't brought up again until 3D, where it's crucial to the plot of the entire game.

Web Comics

 * The current mega-arc of Irregular Webcomic has massive time travellings done by many many characters in many many themes. . Also, Leonardo da Vinci is a time traveller, is British, and made deals with Deaths. Did I mention that TARDIS also exist, and being used by the pirates and British navy crews (the latter owns it (?)), with the theme sets in 18th century? Yeah, it's that weird.
 * In Genius: The Transgression, time travel is possible, but it's almost never a good idea. There's an entire section devoted to time travel and results thereof.
 * In Girls in Space, whenever the girls find the Earth, it is a different time period. They have no control over which time period has appeared.
 * The Adventures of Dr. McNinja. Time-traveling Thomas Jefferson. I don't really need to say it.
 * All Over the House occasionally sees Emily and Tesrin venturing through time for fun.
 * The Life of Nob T. Mouse has Memory Lane, an area of space that allows people to see the past as if it is playing out before them. It's used on occasion to jog peoples' memories.
 * In Fafnir the Dragon, the use of this to prevent a post apocalyptic future is what drives the plot of the first chapter.

Web Original

 * The Global Guardians PBEM Universe features the Warlord, a Powered Armor-wearing villain from the future. He didn't like the way things were going in his time, so he came back to change them. Every story featuring him involves him trying to change some historical event to fit his own whims.

Western Animation

 * In "A Sitch in Time", a three part episode of Kim Possible, all three of the above plots are used. In the end, it turns out that time travel had been responsible for even the initial complication that got the plot rolling (Kim's sidekick moving to Norway) but all was undone by the end.
 * In Futurama, the crew of the Planet Express Ship gets sent back in time to 1947 Earth, and becomes the crashed alien spacecraft at Roswell, New Mexico. Fry does "the nasty in the pasty" and becomes his own grandfather, and Bender's head ends up buried in the desert for 1053 years, in a parody of the Star Trek: The Next Generation episode "Time's Arrow". ("What was it like being stuck in that hole for a thousand years?" "I was enjoying it - until you guys showed up!")
 * In a recent the episode "The Late Philip J. Fry.", this was taken to the extreme where
 * The Venture Bros parodied this in Escape to the House of Mummies, Part 2 (there was no part 1), where the situation became increasingly ridiculous as they traveled around time, leading to Caligula, Freud, Edgar Allen Poe, and two Brocks launching an assault.
 * Darkwing Duck had three time travel stories.
 * 'Paraducks: Darkwing goes to the past, tries to avoid Temporal Paradox when Genre Savvy daughter Gosalyn keeps reminding him of it. Turns out instead he broke a Stable Time Loop. Oops.
 * 'Time and Punishment': Gosalyn ends up Gone to the Future, which turns into a hellhole as Darkwing goes Knight Templar. Oops.
 * 'Quack of Ages': straight-up Reset Button-type adventure.
 * Gargoyles had a magic item called The Phoenix Gate that could be used for time travel. Trouble was, it couldn't be used to change the past. Fate would simply conspire against anyone who tried to.
 * Of course our magnificent bastard villain, is still badass enough to still make his fortune using it.
 * Justice League had quite a few time travel stories, including one entire season that involved parallel universes and a stable but horrifying time loop that would result in a civil war between the world's governments and the world's superheroes.
 * Done a few times in Lilo and Stitch: The Series. Special mention goes to two particular episodes.
 * In "Melty", Lilo makes a fool of herself in front of her love interest, Keoni, and uses Jumba's time machine to go back to the past and change it. However, a side effect of the machine is that something (in a classic Ray Bradbury Butterfly effect) changes in each time line (which usually goes horribly bad). In the end, Lilo learnes a valuable Fantastic Aesop of literally not dwelling into the past.
 * In "Skip", Lilo and Stitch capture an experiment that is able to travel ten years into the future. In the first ten year travel, a seventeen (and shall I say HOT!) Lilo finds out that she has missed out on seven years of her life. When she goes another ten years in the future, everyting is hell. The villain Hamsterviel has taken over the island and the planet, captured all the experiments, and has become king of the galactic federation. Lilo decides that she can't force herself to grow up too early and conventiantly sets the reset button on the experiment to go back to the present time. My personal opinion to this episode is: Why didn't Lilo and Stitch starve to death when all that time went by?
 * Argai the Prophecy plays with this quite a bit, even with an original twist on it:
 * Jimmy Two-Shoes had an intellegent Beezy make a Cool Chair time machine, which he then used mainly to rub his intellegence in Heloise's face.
 * For a series that is so focused on the dangers of advanced technology, The Real Adventures of Jonny Quest notably only had one time travel episode, "The Edge of Yesterday," near the end of its run.
 * In the world of Wakfu, Time Travel is the only time related power the Time Master race of Xelors doesn't possess. The Big Bad has to go on a genocidal campaign that has lasted centuries to gather an absolutely massive amount of Wakfu and pump it into a powerful Amplifier Artifact to make a trip through time possible..
 * The entire final season of The Smurfs was about time travel, coupled with Failure Is the Only Option as the Smurfs end up in one time period (and/or geographical location) after another.
 * The Young Justice episode Bloodlines is all about Bart Allen a.k.a. Impulse trying to prevent a Bad Future and the after effects are really confusing. In the future everything has become destroyed and covered in ash with only Impulse and the villian of the episode in sight. When Impulse changes the future the only thing that changes is that the villain was no longer a major threat in the past and doesn't have scars, but somehow despite changing that little the villian can still remember the old timeline.

Special Mention Goes To
Mentioned in the end, since this series uses (and spoofs) every single trope listed above:


 * Larry Niven's Hanville Svetz series of time travel short stories, collected in Flight of The Horse - where time travel is impossible in the real world, and every excursion that the protagonist makes is into a parallel, fantasy world that then directly affects his own. The reason for the jaunts? Well, the Secretary General of the UN in the series is a little mentally retarded, and the protagonist is sent back in time to recover animals that the SG has seen in recovered children's books. You see, they don't exist in the heavily polluted future... to the extent that, in one story where the proliferation of cars did not take place due to time meddling, one of the supporting characters has to breathe exhaust fumes from a internal-combustion car to stay alive. As is the case with most of Niven's work - it's all scientifically justifiable using the science known at the time of authorship.