Note: I am honored to thank JenniferEmbers for helping me to come up with a part that on my own, I never would have even created. On my last part, which covered the cliché of time travel (again) as well as some of its issues, she brought up other theories about time travel that I should of added in. One of these aspects was the multiple universe theory, a time travel theory I actually am quite familiar with and believe in like the butterfly effect. Because of this, I am going to talk about the cliché of multiple universes in the two ways I have knowledge of; the actual theorized effect from time travel as well as the usage of multiple universes in general. Who knew science was going to help with my fantasy clichés editorial? Also, please check out JenniferEmbers work after reading this, as she is one of the most clever writers I have seen on the site. She deserves some attention herself.
As it turns out, the time travel cliché expands further from just a few inconsistencies with the future as well as the butterfly effect. Time travel can additionally in fiction have a rarer, but still much talked about side effect. In the last part, I did not add this by mistake even when I had full knowledge of this variant. In fact the RPG video game Pokémon Mystery Dungeon: Explorers of Sky, which I gushed about quite a bit for its great usage of time travel, in a sense used this trope in order to justify the existence of your avatar after the future was altered. This fictional trope is known as the multiple universe theory, a concept that is surprisingly easy to understand.
The multiple universe theory involves a possible consequence of changing an aspect of the past. For example in the RPG game I mentioned earlier, your avatar was formally a human from the future whose goal was to stop the paralysis of time in the present. The only way to do this was to collect five devices known as Time Gears (hence my Watt Pad name) and take them to a place known as Temporal Tower to stop the building from causing the paralysis through its destruction. After the mission succeeds, the butterfly effect initially goes into effect and your avatar in one of the saddest video game moments ever disappears into thin air. However, after a few months the guardian of time Diagla decides to bring your avatar back for their selfless sacrifice. The only way to do this though is to make the future they came from exist in a different timeline. Thus, the dark future still exists in another timeline, meaning your avatar is allowed to live peacefully in the timeline they fixed as a reward. It sounds kind of complex, but reading it once over should explain the details quite well.
Now on the bread and butter of this editorial's part; the reason I am calling it a cliché that should not be messed with so much. Creating an alternate universe to avoid the butterfly effect sounds like an easy solution to time travel stories. In reality, doing this will create an even worse problem than being careful with consistency by putting the butterfly effect in mind. Once over, creating an alternate universe is not that bad. In fact, doing so could create a huge window of imaginative possibilities. After doing this multiple times though, it creates the issue of keeping up with all of the time lines in these universes. People will care about maybe two, maybe three of the alternate universes. Expecting an audience to care about twenty different universes with a similar story is impossible.
The biggest offender of the multiple universe trope is surprisingly comics, especially Marvel or DC. Both iconic companies due to their hit comics lasting decades with audiences has caused them to retell origin stories through the usage of multiple universes. Some of these retellings are a good thing and make the characters even more respected. Most of the time though, these retellings can be quite confusing and unnecessary. In one universe, Batman's parents could have been killed by a random robber, causing him to become the dark knight we usually associate him with. In another universe though, Batman could have died as a child, his mother goes insane and becomes this universe's Joker, and the father instead becomes the actual Batman. And then in another universe, Cat Woman is the victim of this tragedy instead, becoming the hero of this world while Batman becomes the villain with a different childhood in play. After the third one, you are probably starting to get a bit confused.
The worst part of this multiple universe trope is when they do a crossover. When this occurs, things get confusing and quite messy with consistency. An iconic character like Deadpool could end up being killed and the character stays alive in multiple other universes, causing mass confusion to someone who just started reading Marvel comics. Timelines could be altered again, ruining character development or worse your own sanity from trying to make sense of the plot. If you like consistency, these types of stories are going to drive you crazy. Established canon means a lot to the audience and prevents the dreaded flame war online. Do the opposite and you basically made your bed.
So again like in the last part, multiple universes should only be used if you have the skills to pull it off. Otherwise, you are going to massively confuse the audience and yourself. This is another reason why time travel in fiction should not be played around with so loosely and carelessly.