I spent too much time on this to not show it off more.
This post will stay focused on the timeline of the games itself. There's plenty to talk about for it.
Why make this now? Well aside from the fact that I like making these things, I recently got the itch to iron out the story for my trainersona; so I looked up a couple of timeline vids on YT to start off and... it completely shattered any understanding and ideas I had about the pokemon timeline I had since I was like, 15. I used to have all the games in sequence, with barely any time in between except for the 3 year gap in gen 1-2 and the unova time skip; well turns out I was very wrong!
So, gen 1-3 and gen 2-4 apparently happen around the same time, there is then an undefined amount of yrs after which comes gen 5, with the sequels happening at the same time as gen 6 (old deleted tweet from a game freak dev). This alone exploded my brain point blank.
After that the timelines are calculated using info from either in-game dialogue or stuff like the characters official concept art.
For example: Grimsley concept art for Alola says that he's supposed to be 2 years older than his last unovan appearance, putting SM/USUM 2 years after BW2.
Another big one is porygon's pokedex entry in the Alola games saying that it was created 20 years ago, yes it's a reference to the passage of time irl, but in-universe it helps to give some more structure to the timeline. It has to exist before gen 1, so taking away the years already accounted for (supposing the events of each game happen over the course of a year + the known time gaps) that leaves about 9 years to play with.
How we distribute that 9 years gets... complicated; and that's where the Fallers and the concept of alternate timelines come in! Namely Annabelle. She's originally from emerald and was sent across dimensions to the other timeline 10 years before the start of gen 7, meaning between gen 1-3 and gen 7 there have to be at least 10 years.
This was the reasoning I saw in the theory vid... however that vid doesn't take into account the amount of time that the events of each game takes, only the year gaps. The resulting math was that the gap had to be at least 3 years (10 - [3+2+2] = 10 - 7).
However by giving actual time to the games (again 1 year each) the calc actually goes into the negative: 10 - [(1+3+1)+(1+2+1+2)] 10 - [5+6] = 10 - 11 = -1 years. Aka there could be no time gap between gen 4-5 and there would still be 1 year where Annabelle is still in Hoenn post gen 3. (I know that it's a bit confusing bear with me)
Why mention this at all then? Because I had to go through this conondrum so you have to, ok? Ok but no really, I just want to have the math written down so I don't have to do it again.
We see Caitlin age visibly between gen 2-4 and gen 5, plus there's a team rocket grunt that moved to Unova and had kid that's already talking and walking around, so the gap has to be some years at least.
The gap between Porygon's creation and gen 1 should be at least 1 year (again some official material say it was made in 1995 and that OG Red started his journey in 1996), with that both gaps can be between 1 and 8 yrs, with the gen 4-5 gap having more sense if it is above 4/5 years (again, Caitlin went from teen to adult and the rocket grunt's kid).
OK. Now that we got that all sorted, you can see I kept the og non-mega timeline with a bigger time gap, and then in the mega timeline I scooched gen 1-3 a bit forward because the technology in ORAS does seem more advanced.
And that's the passage of time explained!... now we can talk about the timeline splits... my god.
We know from the delta episode that there is a mega and non-mega version of pokearth, but it gets deeper then that (if you don't get meta about it, realistically they simply fudged up the lore when writing between XY and ORAS).
But let's start with the gen 1 split: originally I had the OG games in the non-mega timeline and the remakes in the mega, but upon more research and video essays it makes more sense that the gen 3 remakes are what parallels the Hoenn games. Why? The trading system. Again, if you get meta about it, it's just a game mechanic, but there are npcs that give lore about making a machine to trade with trainers from Hoenn in FRLF so.. it makes sense to have things set up like this.
So! We end up with the non-mega timeline having a split: the classic/abandoned timeline and the remake timeline. You may also notice I put yellow in its own little bubble; since it was made as an homage to the anime and keeping it with the other games would've cluttered the spot, I used it for the anime timeline! Maybe at some point I'll go back and write down all the seasons and movies in order.
New version of the big split thanks to Legends Z-A: X/Y and ORAS are now both on the mega timeline, now the non-mega timeline is properly without any mega evolution and that makes the cause of the split less convoluted to explain.
It all goes back to Az and the ultimate weapon, and whether he fires it or not, here we enter into even more speculative territory but I think my reasoning makes sense, here we go:
Right before the split: Az creates and uses a machine to drain a bunch of life force from many pokemon to revive his floette, both he and her become "immortal", and after finding out what he did to bring her back, floette leaves. Az is overcome with grief and anger, directed to the war and the people in it and now has an unimaginably powerful tool at his disposal.
In the non-mega timeline AZ doesn't convert into a weapon or fire the tool. Mega evolution doesn't exist and Groudon/Kyogre never undergo primal reversion.
In the mega timeline he does turn the machine into a weapon and fires it; everything happens the way we know from the modern games.
In the non-mega timeline he chooses to fire the weapon and end the war (I know, I know just bear with me), this caused the whole region of Kalos to be infused with infinity energy that goes on to create mega stones. In this timeline mega evolution is discovered in Kalos first and only later gets potentially ported to other regions (explaining Sycamore's dialogue).
In the mega timeline Az decides to not fire the weapon on the region, and insted fires it off into space to discharge the energy. The beam travels ways away and eventually hits a meteorite, changing its orbit and sending it on a collision course with earth many centuries later. When the meteorite comes, Rayquaza destroys it from the stratosphere and pieces of it rain down all over the world, with three particularly big chunks falling on Hoenn. Two land near Groudon and Kyogre's resting spots, causing them to undergo primal reversion and start rampaging, the other in Meteor falls. The draconid people call to Rayquaza for help, who having absorbed energy from the impact with the meteorite becomes the first pokemon to mega-evolve and puts a stop to the other two's fight. The primal enery is redirected back into the two meteorite pieces that become the red and blue orbs. In this continuity mega evolution is more wide-spread from the beginning.
We know the events of the non-mega games still happen so I put little greyed out icons with mega symbols in the mega timeline.
The let's go games are in their own little timeout corner because they make no fucking sense in relation to the others. Both because of the new protagonists and because Mina is there and from her concept art she's 13-14, while she should be less than 20 in SM/USUM (which is wild btw, but I'll discuss my qualms with character ages laterrr, here we're trying to stick to the original sources).
You may notice I've not been talking about anything from gen 8 onwards, and that's because we have no concrete evidence for how much time has passed. They realized they've been writing themselves into a corner, so they starded referencing the older games as little as possible, and if they do they don't give concrete times.
New: We now know that the events of gen 8 have to also happen between 1 to 2 years after gen 7 thanks to Leon being referred to as having been defeated by the time Legends Z-A happens.
We know gen 8 has to be a while after gen 7 because documents on type: Null have been stolen and replicated in Galar, and we know gen 9 has to be a while after that because Sonia's book has been published and is being sold widely enough to end up in a school (tough it is a prestigious school, so they could've had early access).
That's about it, aside maybe from Lacey being Clay's daughter, but we don't know how old she is or if she was already born during gen 5.
As for the last timeline... that's where my trainersona comes in :>
The og timelines are already confusing enough without trying to shove a non-canon character in it, and besides if multiple universes are canon, we can just pull a spiderverse >:3c
So yeah, this is where I'll focus all my headcanons and interpretation of canon characters! I plan on expanding more on that on a properly focused post.
For now the short form is that it's an offshoot of the mega timeline that happens when my trainer gets dimension hopped to the pokemon universe in some way.
Jeebus this is so much writing but there is no concise way to explain all of this ToT.
Pokemon by Nintendo/Game Freak
art by me, do not copy, trace, repost, reuse ecc without my permission please.