Time Travel - Television Tropes & Idioms

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

— Isaac Asimov

"I would not want to bet against the possibility of time travel. My opponent might have seen the future and know the answer."

— Stephen Hawking

"Time travel. It's a cornucopia of disturbing concepts."

— Ron Stoppable, "Kim Possible"

(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 Town, or the phlebotinum involved can be a key plot driver. No matter what story type the hero is going to need a Time Machine. Time Travel stories seem to fall into several categories:

You Cant 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 a Stable Time Loop (see below). (According to some scientific schools of thought, this is exactly how time travel would work in real life - relativity allows travel into the past, but quantum physics won't allow anything to happen that would change the future the traveler came from)
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.
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 Cant Fight Fate, but in the present rather than the future.
- Includes cases of the Wayback Trip.
Temporal Paradox: Now it gets complicated...
- 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 Twilight Zone Twist; alternately, it will set the real plot in motion by requiring the characters to Set Right What Once Went Wrong. 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."
- 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.
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-travellers remember — at least, the ones who were alive at the point of fix. If they don't succeed, the series has just received a Re Tool.
Connecticut Yankee: 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.

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 encounter with the Butterfly Of Doom or with accidentally leaving behind Grays Sports Almanac.

Time Travel stories that are prone to phlebotinum rules

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.
The Terminator series.
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 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, 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 MIBs, as seen in DS9.)
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.
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 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.
In Jean Claude Van Dam's Timecop, there's a federal agency responsible for going after people who attempt to go back in time. He winds up having to go back in time himself to save his wife from dying, which is what he was hired to keep other people from doing.

Series that featured time travel in a major way

The Time Machine 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.
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.
Planet Of The Apes
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
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.
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.
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. Later still, one Worm could actually freeze time, strongly enough to even beat Hyper Clock-Up.
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, Hana, doesn't do the job remains unexplained.
- Because she's a girl.
  - While that may be the real reason, there is another explanation given on the show. In order to fight she'd have to agree to let herself be possessed by one or more of the Monsters of the Week in a symbiotic relationship and she hates them too much to agree to that.
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.
Time Squad involves time travel in almost every episode, as its name implies.
Chrono Trigger.
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.
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 thorugh time with her) time travel was relegated to a Save The Day plot device.
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)
Meet the Robinsons.
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.
The Suzumiya Haruhi stories feature time travelers, most notably Mikuru. It get's important in a major way in the novels, which also push Mikuru from being the Neutral Female somewhat. They travel to 3 years ago, and holy shit! Kyon is the goddamn ~~Batman~~ John Smith! The 7th novel also circles around it, this time from the future.
Earthsong features a particularly head-spinning variant that doesn't actually CHANGE TIME AT ALL.
Zipang, where a JMSDF destroyer somehow ends up at the Battle of Midway. It's actually much more interesting that it sounds.

Some series that occasionally called on the trope

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.
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!")
The Futurama bit is very similar to a bit in the The Restaurant at the End of the Universe where Marvin the Paranoid Android is abandoned for most of the lifespan of the universe due to time travel. “The first ten million years were the worst, and the second ten million, they were the worst too. The third ten million I didn't enjoy at all. After that I went into a bit of a decline.” It is later stated that, due to his various time travel incidents, Marvin is several times older than the Universe itself.
- The Hitchhikers 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.
Stargate SG-1 had several episodes involving time travel—"1969" when they travel back to said year due to Stargate mishaps, Groundhog Day 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 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.
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.
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.
One part of Apollo Justice: Ace Attorney's fourth case involves using the "MASON system" to investigate witnesses and crime scenes from seven years ago and the present day. The player must go into scenes from the future, obtain evidence there, then go back and present that evidence. This part of the game is particularly controversial amongst fans of the series; spirit channeling and a courtroom where lawyers shout at each other, whip witnesses, and drink 17 cups of coffee is one thing, time travel is another.
- It's meant to be some kind of 'game' or simulation. Or something. No-one really knows.
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.
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.
The current mega-arc of Irregular Webcomic has massive time travellings done by many many characters in many many themes. This might be a Xanatos Gambit on the part of the author to resurrect himself and Screw Destiny after he got killed by himself in the future and becomes Death of Going Back in Time And Killing Yourself and is suppose to go back and kill himself to continue the Stable Time Loop. 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.

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

Larry Niven's 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.