'''Basic Trope''': Despite changes in the past, improbable events still have occurred in the present.
* '''Straight''': Bob goes in back in time to kill Hitler before UsefulNotes/WorldWarII and succeeds. He still exists in the new timeline that results from this event, despite his dad's parents originally having met in the war.
* '''Exaggerated''': Bob destroys the asteroid that killed off all the non-avian dinosaurs. Humanity still evolves.
* '''Downplayed''': Bob creates a minor obstacle in the way of his grandparents' courtship. They still get together.
* '''Justified''':
** There's a TimePolice, GuardianOfTheMultiverse, or other mysterious forces that try to keep the timeline on track.
** Alternatively, since Bob changed history, he still exists in order to prevent a paradox.
** When Bob travels to other universes, he ensures his machine can only send him to realities where he exists. Since there's an infinite number of worlds, he could find a version of himself [[GodwinsLawOfTimeTravel where the Nazis won WWII.]]
** When Bob kills Hitler, he creates an alternate timeline where Hitler died before World War II. This isn't tied to his own timeline, in which he's still alive.
** Bob's grandparents would have met somewhere where the war didn't take place. Even in times of peace, they would still meet during the 40s.
** RubberBandHistory
* '''Inverted''': PointOfDivergence.
* '''Subverted''': Bob is shocked when discovers he prevented his father from being born.
* '''Double Subverted''': It turns out that his father was born in a different part of the world. And his father is even somehow the exact same person in spite of this.
* '''Parodied''': Bob causes many changes during his time travel trips, but no matter what, his parents will still meet and his favorite movies still exist.
** Bob is relieved knowing he was still voted prom king in high school despite going eons back in time and accidentally destroying the Earth before it was fully formed.
* '''Zig Zagged''': While the new present appears to be very different from the old one at first, there are still inexplicable similarities.
* '''Averted''':
** History changes in the way that one would expect it to happen.
** No one tries to change the past.
* '''Enforced''':
** "We don't want to scare people into thinking that they might accidentally wipe themselves from existence."
** Conservation of [[LawOfConservationOfNormality normality]] and [[TheLawOfConservationOfDetail detail]] are more important to the work's creators than realism, so they simply decide to rely on WillingSuspensionOfDisbelief for the sake of storytelling.
* '''Lampshaded''': "I can't help noticing how some things remain the same in this new timeline."
* '''Invoked''': Bob says that he knows that if he kills Hitler, his paternal grandparents will still meet.
* '''Exploited''': A time traveler or a group of time travelers explicitly made changes in some way with the past to their liking, knowing full well that they themselves won't change in any way.
* '''Defied''': Bob made sure to change every single thing he can think of to make sure the present he came back to will be completely different.
* '''Discussed''': "TimeTravel does not work that way. If you managed change something in the past, there are bound to be some unexpected consequences!"
* '''Conversed''': "Why is it that whenever these characters succeed in changing something, there aren't ''any'' unexpected consequences?"
* '''Deconstructed''':
** It turns out it has an effect later on.
** It's not having an effect because [[TimeCrash something bad has happened to time itself.]]
* '''Reconstructed''': The world is much better and everyone is happy.
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You know, even if you went back in time and made sure nails were never invented, you'd still be able to go to {{In Spite of a Nail}}.
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%% Optional items, added after Conversed, at your discretion:
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%%* '''Implied''': ???
%%* '''Plotted A Good Waste''': ???
%%* '''Played For Laughs''': ???
%%* '''Played For Drama''': ???