'''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 WorldWarTwo and succeeds. He still exists, despite his dad's parents having met in the war.
* '''Exaggerated''': Bob destroys the asteroid that killed off all the dinosaurs. Humanity still evolves.
* '''Downplayed''': Bob creates a minor obstacle in the way of his grandparents' courtship. They still get together.
* '''Justified''':
** There are 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.]]
* '''Inverted''': ForWantOfANail
* '''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.
* '''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.
* '''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.
* '''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.
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}}.
%% Optional items, added after Conversed, at your discretion:
%%* '''Implied''': ???
%%* '''Plotted A Good Waste''': ???
%%* '''Played For Laughs''': ???
%%* '''Played For Drama''': ???