TV Tropes: Time Travel

See also: Time Travel Tropes for similar examples

Time travel can be used in a wide variety of stories. It can serve as nothing more than a means to get The Hero from one Adventure Town to the next, or it can be the impetus for the entire story as the characters try to unravel the mystery of the Nonsensoleum. Time travel stories, however, can be grouped into the following broad categories.

1. The heroes travel into the future, only to discover a dystopian landscape where bad things are inevitable under the current conditions. They go back to their own time, determined to stop the Bad Future from happening. They could be successful, but if they aren't, it's probably because Fate is Unstoppable, and There's Nothing You Can Do About It.
2. It's a stable time loop where the protagonists travel to the past but end up realizing they can't alter the past. You've altered the past anyway, so any potential interactions between them and earlier events are already accounted for in the timeline. When You Can't Fight Fate, but It's the Past You're Up Against Other times, it's a Wayback Trip: the heroes go to the past, realise that history is different from what they thought it was, and then change it so that it conforms to what they "know" as history — they think they "changed the past", but history already accounted for their actions
3. Right Past Wrongs: Our heroes travel through time once again, but this time it's because they recognize that mistakes were made and they want to make amends in order to create a better "present." Nonetheless, there are a few variations:
   • Change What Was Right The bad guys travel into the past to alter events so that they will benefit more in the present. Whatever is good for the bad guys is almost certainly bad for the good guys. It can lead to a situation reminiscent of the movie Terminator, where the good guys go back in time to stop the bad guys from altering history.
   • Reversing a previously positive action can have unintended consequences, such as the creation of a Bad Future, the activation of a Temporal Paradox or Time Crash, or the wrath of the Clock Roaches. In that case, everything would go back to how it was before the heroes intervened, which would require them to travel through time to undo their actions.
   • The Hitler Time Travel Exemption Act states that there are situations in which changing the past could irreparably alter the outcome of the story. If it doesn't improve the situation (e g time travel is impossible because either the original antagonist is replaced by something worse, or the world we live in today loses the technological and social progress that was made possible by the original conflict. Anyway, there's no way to change history by stopping World War II in its tracks by eliminating Adolf Hitler.
4. The situation is reset by having the protagonists travel through time to alter the past and thus the present. If they do it, nothing needs to be done and everything goes back to normal. Even the time travelers themselves, barring the possession of Ripple-Effect-Proof Memory, will not recall the past's deviations.
5. After traveling back in time, our heroes find themselves unable to escape the events of their past. This forces them to devise a plan for reentering the future. If they can't, they have to decide whether to keep to themselves and try not to change the past, or to use what they learn in the future to improve things. Perhaps they will find that they are stuck in a Stable Time Loop and cannot alter the past, present, or future. It's possible that if they take The Slow Path, they will be able to return to the present.
6. In this alternative history, the heroes alter the past in such a way that the universe is now in two halves. The future will never be the same again thanks to the actions of time travelers, setting it apart from a Stable Time Loop. The book in question determines whether the time travelers can return to their "original" timeline or are doomed to stay in the parallel one.
7. Groundhog Day Recurrence: Our Heroes Keep Reliving the Same Past Events In order to move forward in time again, they must figure out how to escape the loop, and this is often done by drawing on the knowledge gained from reliving the same past event multiple times.
8. "San Dimas Time" is a time travel story in which the heroes must race against the clock to prevent a catastrophic event from occurring in the present. This would never make sense under normal circumstances, since you wouldn't be able to stop a bad future event from happening until that future event actually occurred. But in this type of story, after a certain amount of time in the past, there is some mechanism that prevents the heroes from changing the future. Occasionally, this is the result of a Delayed Ripple Effect, wherein the timeline has been altered, but the change hasn't "caught up" with the protagonists yet, giving them a window of opportunity to undo the damage before it is too late. In either case, it allows for a Time-Clock-style race in a story involving time travel.
9. If you thought that was complicated, wait until you encounter the paradox of time travel.
10. Timey-Wimey: All of the preceding can be in effect at once.

Clearly, the many permutations of Temporal Mutability play a role in these narratives. Characters may be Wrong Genre Savvy and assume they are in one type of story when they are actually in another because they expect a certain change to be possible when it isn't, or vice versa.

The following elements are common to nearly all time travel stories, regardless of the specific plot:

• A device, typically a Time Machine, for time travel. Because time travel is so far out there in the realm of Speculative Fiction, it typically uses Applied Phlebotinum as its power source. Some methods of time travel are instantaneous while others are not, and still others have nothing to do with your physical form. The heroes may have trouble getting it to do what they want or finding Phlebotinum to power it because they will not fully understand how it works in any of its forms. As opposed to that, a Time Master is almost always competent in their endeavors.
• They have a scientist or scholar who knows more about time travel than they do. They constantly issue dire warnings about the dangers of temporal paradoxes because they believe time travel to be an unproven phenomenon. Even if it's possible in that story's timeline, they'll still be wary of a Butterfly of Doom or a Timeline-Altering MacGuffin. It's not uncommon for them to give off the impression of being Reluctant Mad Scientists, people who are interested in attempting some kind of radical scientific endeavor but are fully aware of the potential dangers involved.
• Assembling the Screws in Your Head As a species, we tend to think of time as passing steadily in one direction. The very idea of logic as we know it would be destroyed by anything outside that. Consecutive events occur — until they don't. Characters in time travel stories always struggle to understand the chain of events they’ve created. They might even run into trouble while time-traveling. A Stable Time Loop or an impassibility to return from an Alternate Universe are the only possible resolutions to the story that are even remotely consistent with the typical ideas of causality; stories that strive to be more "realistic" tend to favor these.

Attempting to make a time travel story "realistic" is a very odd thing to do. There's zero evidence that time travel is even possible in the real world. The rules of time travel should be consistent with the story, rather than realistic. Time travel stories are already difficult to construct without this additional difficulty. If you err too much on the side of consistency, your audience will be thrown into a tailspin trying to make sense of the tangled web of causality you've created (i.e., they won't be e , the viewer may notice flaws in the story that weren't there to begin with) If you go in the opposite direction, where there are no repercussions for careless time travel, you run the risk of Opening a Can of Clones, where the audience stops caring about the plot because they assume that a time traveler can simply alter the future however they like. That was then (or earlier.)

Also check out What Year Is This? (on how your characters can figure out that they've traveled through time) and Meanwhile, in the Future... (on how to run a story in two time periods at once).

Time travel in the following works of fiction: