I really hate it when time travel rules become convoluted and inconsistent. It reminds me of when Savitar made fun of the Arrowverse's time travel logic where the more you do it, the less the rules apply to you. It frustrates me how selective the TVA is with resetting branched timelines. Though I guess with Pompeii, with no survivors how do we know Loki and Mobius wasn't already there and their presence was fulfilling a Novikov time loop? Oh, right, because Marvel never really established time loops. Elena Rodriguez was afraid of a loop when her arms were cut off but there was still never a true time loop that established the Novikov principle in the MCU like Harry Potter and the Prisoner of Azkaban or Lost. Although what happened in Harry Potter contradicted what Hermione said and what was on Pottermore and the stage play Harry Potter and the Cursed Child. Can't we ever get time travel rules that don't change with the plot? If the past cannot be changed, don't change the timeline. If there's multiple timelines branching into a multiverse, have a multiverse. If changing the past changes the world of your present, keep it going like that. If there is a time police trying to maintain a "sacred timeline" have them going after time-travelers, not innocent bystanders affected by time traveler actions! There would be massive butterfly effects from Tony's cardiac arrest, HYDRA believing Captain America was one of them, Captain America fighting himself and learning that Bucky is alive two years early. And none of that would be Loki's fault because Loki didn't know about HYDRA. He was only escaping in the confusion when Hulk burst from the stairs and knocked the Tesseract out of the future Stark's hands. How could Tony have forgotten about Hulk taking the stairs?

The way that I see time travel in the MCU is like your stated type A, where there was always an existing multiverse. Now the idea of a Sacred Timeline kind of seems to contradict this idea, but I think it still works.

The time travel as explained in the MCU is that when you travel to the past you can't actually change your own past. Therefore since Endgame I have taken the multiverse approach to time travel, which (at least for me) makes the most since. The characters aren't actually traveling through time, but instead to alternate universes that are identical (at least from what we are able to see) to their own, except for the fact that that universe is at a different point in it's timeline (meaning that universe didn't come into existence until after the MCU, a "younger universe"). This version of time travel works with the all Endgame time travel, as long as you assume that Steve Rogers was able to make it back to the MCU through a time machine that was created in the alternate universe that he went to (which makes sense because they probably would've time traveled as soon as there was enough Pym Particles to return all the stones and return home so he would have had to wait in order to come back and this also explains why and how he brings back with him a brand new shield).

Loki seems to show that this is incorrect though, saying that there is only one Sacred Timeline, but I think that the multiverse still exists and the same time travel rules still apply. Firstly it is said that what the Avengers did was supposed to happen, and as you mentioned the events caused by the Avengers clearly couldn't have been their past. Thus as part of the Sacred Timeline, the TVA must be allowing pocket universes, alternate universe that are dependent on that of a main universe, similar to that of type B mentioned above (Disclaimer: I'm not exactly sure if this is the actual definition of pocket universe/dimension, but this is what I mean when I say pocket universe from here on). Now along with these pocket universes, I believe there are also other universes still there and that the TVA's goal is to ensure that all universes in the multiverse adhere to the Sacred Timeline. This is why Mobius mentions that their job will be done at the end of time when everything is in order, and also why Loki is able to travel to Pompeii at one point even though that didn't normally happen. The TVA is only looking for universes that are approaching a "red line," thus causing a complete separation and contradiction of that of the Sacred Timeline. Therefore, in short, the TVA time travels to other universe that are currently at that point of time to stop variations before that universe becomes different from the Sacred Timeline, and the Avengers time traveled to pocket universes which are dependent on their own and are allowed by the TVA because it is a required part of the Sacred Timeline.

***Side Note for Marvel TV time travel

I believe that the AoS time travel works just like the Avenger's time travel, as they both make use of the the Quantum Realm and this could explain why the snap doesn't occur in AoS. I know that there are some people who believe that AoS did end in the main timeline, but I think it just makes the most sense for them to have been travelling to different pocket universes since they jumped into the future in season 5, because this follows the rules of time travel and makes the most sense to me, as it was the creation of Tony's time-space GPS that allowed the Avengers to get back to the MCU, whereas the Agents must have been unaware that they returned to a universe that was not their own.

I can only assume that this is how Runaways time travel works as well, but I haven't finished the show yet so I am not completely sure.

@BEJT Yea this confusion is why I believe there to be some lying by either Ravonna, the Time Keepers, or the TVA.

Well now that the show is done (or rather, the first season) what do you guys think?

@BEJT How do you think the apocalypse events work? I was under the belief that the 'apocalypse loophole' allowed you to travel to the Sacred Timeline without branching off, so anything you did there was part of the main timeline's history.

Loki mentioned how you can throw Hulk off the rainbow bridge during Ragnarok with no consequences, but that would contradict the movie. Especially since Hulk was one of the survivors of Ragnarok. And he could only know about Hulk being in Asgard from that video of his life's story. So even if throwing Hulk off the rainbow bridge doesn't cause a Nexus event, it would still be a branching timeline because no time traveler threw Hulk off the bridge. And the ending of Loki with Mobius not remembering the title character and the statues of the Time-Keepers replaced with Kang, isn't that the Back to the Future kind of stuff that Endgame made clear doesn't work in the MCU?

Okay, I've put some time now into replying to everyone's points. I'm including some links to my blog to save explaining some of my thoughts in detail for yet another time - it's out-of-date but covers many of my Endgame thoughts. The blog is hopefully going to be organised better in the near future so the links may become broken at some point, but they're the right links for now.

@MJLogan95

"That first episode also has the TVA state that the branch in 2012 occurred after Loki escaped with the Tesseract, thus making it sound as if everything before that (Ant-Man giving Tony cardiac issues, Cap fighting Cap, Cap saying "Hail HYDRA" in the elevator) was all part of the main Sacred timeline. ... How is that possible??"

Yeah, it's not. Whatever the reconciliation is with this show, it's not to assume that's part of the main timeline.

"The second Loki episode ("The Variant") reveals even more. Going back in time does not automatically create an alternate/branched timeline."

To be fair, this has always been my opinion even with the Quantum Realm, from what Endgame presented ( https://marvelcinematicuniverse.fandom.com/wiki/User_blog:BEJT/Time_Travel,_Timelines,_the_Multiverse,_and_Related_Topics:_The_Marvel_Cinematic_Universe%27s_Rules#Result_13 ).

"Loki even says he could go to Asgard right before Surtur initiated Ragnarok & knock Hulk off the Rainbow Bridge (which obviously didn't happen in Thor: Ragnarok) and that, due to this little 'loophole', it would not branch out the timeline whatsoever but would be part of the Sacred one."

Yeah, this is a really stupid line in the episode. Not only would pushing Hulk off the Rainbow Bridge in fact make a difference to the event in general, but it's an established event we have seen where we know Hulk isn't pushed off, so it would have to be a branch. I think we have to assume Loki doesn't know enough about the event... despite reading a file on it immediately prior.

"This, coupled with the Loki episodes revealing that the 2012 branch started when Loki escaped with the Tesseract and not when the 2023 Avengers arrived there [...] At the moment, the wiki is operating under the rules that 2012/Time Heist formed when the Avengers went back in time, but the Loki show reveals that the alternate timeline didn't exist until Loki escaped with the Tesseract. How then do we sort out the Avengers Time Heist stuff that occurred before Loki's escape, as it would suggest it was part of the main timeline?"

This is not my understanding (may be what the show is clumsily trying to imply, unclear - but it can't be the ultimate truth). Given that they have to be in a branch timeline already - a branch timeline that's apparently part of the plan - the Nexus event (breakaway from the *plan*) has to be off of this branch timeline, so Loki stealing the Tesseract is a branch on the branch. The Avengers, if you ask me from what Endgame presents, erased the branches they created anyway ( https://marvelcinematicuniverse.fandom.com/wiki/User_blog:BEJT/Time_Travel,_Timelines,_the_Multiverse,_and_Related_Topics:_The_Marvel_Cinematic_Universe%27s_Rules#Result_20 ), which perhaps works with why the TVA let those branches go.

This doesn't then answer why the Avengers still clearly acted upon Loki stealing the Tesseract in Endgame, if Loki taking the Tesseract was a Nexus event erased by the TVA to make sure that it didn't happen, but no theory really works with that. It's a gaping hole in the show. It also doesn't answer why they specifically even went to 1970, which it seems was "meant" to happen, because of this event that wasn't meant to happen. *Sigh.*

"The TVA report file list the the D.B. Cooper hijacking somehow counts as apocalyptic (somehow)."

It does? That's weird. That's very weird.

"However, with what we've seen so far from Loki, it seems implausible Steve's branched timeline could go on for 70 years without nearing Red Line."

Agreed, though I've always been of the Markus and McFeely opinion ( https://marvelcinematicuniverse.fandom.com/wiki/User_blog:BEJT/Time_Travel,_Timelines,_the_Multiverse,_and_Related_Topics:_The_Marvel_Cinematic_Universe%27s_Rules#Result_39 ). But I do think Loki further supports it. Kate Herron doesn't seem very sure how it fits together, which doesn't surprise me.

"Also, If you can go to the past right before an 'apocalyptic' event, then did Thor & Rocket go to the actual 2013 past & speak to actual Frigga, instead of creating 2013/Time Heist?"

There's no concrete reason to believe this, and the branching of the Avengers' actions appears to be to do with taking Infinity Stones (as the Ancient One mentions in Endgame) and not to do with creating Nexus events (which aren't inherently tied to time travel, only any instance of stepping off He Who Remains' path).

"How do you think the apocalypse events work? I was under the belief that the 'apocalypse loophole' allowed you to travel to the Sacred Timeline without branching off, so anything you did there was part of the main timeline's history."

Yes, if they're not branching off, it means they have to be part of the main timeline's history all along by default. Presumably, "the timeline" (specifically He Who Remains? however he governs these things) has a certain planned path but it/he will allow tiny variations from that plan to be incorporated into the actual resultant timeline, so long as they're negligible deviations from the plan. A Nexus event being a proper deviation from the plan that can't be "allowed" to be in the timeline and has to branch and be pruned. The show waves this away as being to do with "variance energy" levels.

@Danger1109

"I'm guessing if they travelled to the current in-universe year of 2024, everything would be like we've seen play out on screen already?"

Sorry, I'm not sure what point you're making. If they travelled to 2024, the prime timeline events would be what we have already seen. So, if they were fitting into the timeline then they would fit in with those events, and if they were branching then they would be changing things from that baseline.

@MarvelSilver-44

"Cap speaking to the Hydra agents was undone when cap returned the mind stone I assume like most of the other things the avengers changed e.g taking thors hammer from the past."

I'm of the opinion that Endgame presents that the Avengers' branch timelines were erased by Steve ( https://marvelcinematicuniverse.fandom.com/wiki/User_blog:BEJT/Time_Travel,_Timelines,_the_Multiverse,_and_Related_Topics:_The_Marvel_Cinematic_Universe%27s_Rules#Result_20 ).

@SeanWheeler

"Though I guess with Pompeii, with no survivors how do we know Loki and Mobius wasn't already there and their presence was fulfilling a Novikov time loop?"

The way I see it, this has to be the case. If they're not branching, by default they're part of the timeline, which by default means they're fulfilling their destined actions. See my response to MJLogan95 above. It's unclear if the show has thought this through, though.

In general with your message, I agree with your frustrations.

"Loki mentioned how you can throw Hulk off the rainbow bridge during Ragnarok with no consequences, but that would contradict the movie [...] So even if throwing Hulk off the rainbow bridge doesn't cause a Nexus event, it would still be a branching timeline because no time traveler threw Hulk off the bridge."

Yep. I can only assume Loki didn't know that this definitely didn't happen... (well, really I can only assume the writers were clumsy).

"And he could only know about Hulk being in Asgard from that video of his life's story."

Or the file, he might know from the file.

"And the ending of Loki with Mobius not remembering the title character and the statues of the Time-Keepers replaced with Kang, isn't that the Back to the Future kind of stuff that Endgame made clear doesn't work in the MCU?"

I'm hopeful that it's not. I think the Mobius we see a few minutes before that final scene seems to be our Mobius, so I hope he wasn't just "reset" in some way "between" those scenes. But there is no clear way in which the ending makes sense as things stand, since these things seemingly can't be rewritten but also there is seemingly only one TVA. Just waiting on answers for this one.

@Jt3enigma

"The way that I see time travel in the MCU is like your stated type A, where there was always an existing multiverse. Now the idea of a Sacred Timeline kind of seems to contradict this idea, but I think it still works. The time travel as explained in the MCU is that when you travel to the past you can't actually change your own past. Therefore since Endgame I have taken the multiverse approach to time travel, which (at least for me) makes the most since. The characters aren't actually traveling through time, but instead to alternate universes that are identical (at least from what we are able to see) to their own, except for the fact that that universe is at a different point in it's timeline (meaning that universe didn't come into existence until after the MCU, a "younger universe")."

Was it you who I had a brief discussion with about this recently? I personally disagree with this, as the MCU frequently talks about branches/splits and has never implied that branches are actually identical parallel universes. It's also incredibly convenient that they should just happen to find universes very similar to theirs every time, nor is that even directly time travel so much as just hopping to another universe like what the agents of S.H.I.E.L.D. do in the show's finale, which is a distinctly different thing. I don't personally see the need to make this assumption, which I see as a big assumption. But I accept that the MCU has been a mess with rules and understand why you might turn to this option.

In general with regards to there being a multiverse, I don't necessarily disagree with it potentially always having existed in some capacity, but not for this reason.

"As long as you assume that Steve Rogers was able to make it back to the MCU through a time machine that was created in the alternate universe that he went to."

I will forever stand by that what Endgame tells us about the time travel rules would make Steve's time travel part of a loop through the MCU and not any sort of branch timeline ( https://marvelcinematicuniverse.fandom.com/wiki/User_blog:BEJT/Time_Travel,_Timelines,_the_Multiverse,_and_Related_Topics:_The_Marvel_Cinematic_Universe%27s_Rules#Result_39 ).

"Loki seems to show that this is incorrect though, saying that there is only one Sacred Timeline, but I think that the multiverse still exists and the same time travel rules still apply. Firstly it is said that what the Avengers did was supposed to happen, and as you mentioned the events caused by the Avengers clearly couldn't have been their past."

I agree that there is an element of the multiverse still probably involved in the pre-Loki time travel rules, and that this is necessary for the Avengers' actions (I believe that they created branches, they just also then pruned them with Steve returning the stones ( https://marvelcinematicuniverse.fandom.com/wiki/User_blog:BEJT/Time_Travel,_Timelines,_the_Multiverse,_and_Related_Topics:_The_Marvel_Cinematic_Universe%27s_Rules#Result_20 )). I just don't agree with the preexisting timelines being hopped into during time travel, particularly with the events of Loki and even-more-particularly with the Loki finale (I appreciate this was written last month, before the finale).

"Now along with these pocket universes, I believe there are also other universes still there and that the TVA's goal is to ensure that all universes in the multiverse adhere to the Sacred Timeline."

I also sort of got this impression with just how divergent the Loki Variants would have to be if this wasn't the case... until the finale, which got rid of this possibility. What a pain. Ugh, this show.

"Why Loki is able to travel to Pompeii at one point even though that didn't normally happen."

We don't know this. See my points about this above in response to MJLogan95 and SeanWheeler.

"As they both make use of the the Quantum Realm."

It's only the Quantum Realm in the Season 7 finale, and that's them just returning to their home universe. The time travel isn't via Quantum Realm.

"I know that there are some people who believe that AoS did end in the main timeline, but I think it just makes the most sense for them to have been travelling to different pocket universes since they jumped into the future in season 5"

No, sorry. They travelled back to where they left from (a few months after they left) then saved the world in 2018. Destroyed Earth is a branch timeline future, the saved world is the one they forged, and of course, the main MCU is the one where Earth isn't destroyed in 2018 - the one they're in. The agents survived the Snap and didn't talk about it, and according to Jed Whedon there was actually going to be a reason to do with them being protected by the Quantum Realm in some capacity that they just ultimately didn't include.

"I can only assume that this is how Runaways time travel works as well, but I haven't finished the show yet so I am not completely sure."

Runaways' time travel is different. It basically goes the Back to the Future route, but leaves a lot unanswered and open to interpretation. There are ways to make it work, so long as you make assumptions about how their device works. I actually spoke to writer Quinton Peeples about this, who said it's intentionally nebulous because the characters would be out of their depth and unsure themselves.

Runaways does the Back to the Future route? Aw man, I only saw Season 1 so I don't really know much about the time travel, the Darkhold or Xavin.

It's not too bad, it's not too Back to the Future. But it does involve changing the past enough that you get erased, which has to be chalked up to the fan theories about the way the device works.

@BEJT When I said "everything will play out like we've seen on screen" I'm thinking in my head...If Loki travelled to 2024, would it be the time in which the world knows he died in '18? Or is it an alternate '24 where Loki disappeared in 2012.

Marvel really needs better time travel rules. The time travel rules I've set for my books are that when you travel back in time within the timeline of Verse-617861, Novikov rules apply and everything you do had already happened before you went back in time. Even seeing yourself has to play out the exact same way down to the involuntary stuff. Luckily, your memories are in control of your actions when you talk to yourself, though that would feel weird. And the only way to make changes to the past is to travel to a different universe when you time travel, and even then the differences to the timeline of that universe are isolated from your universe so you won't erase yourself or affect the people waiting for you at home. That is how I would do it. And traveling to an alternate universe would have to be caused by either a time machines settings switched from "Novikov" to "Multiverse", a speedster jumping while running back in time Flash style to send himself or herself hurtling into another universe, or if a time traveler wanted to change the timeline so badly that the only way the Novikov physics of fate could keep the timeline consistent is to send the time traveler to the past of an alternate universe instead of the main timeline.