all that aside, it's absolutely incredible to see both the users who popularized the mew trick show up on this forum over 20 years later! especially as someone who's been checking in on this site every once and a while for some ~8ish years (pales in comparison, but still) and am always happy to see it's still being updated, being a fan of pokemon games and all their weird bugs and quirks is something you can never really fully lose interest in and i think that's wonderful
Ahaha, I'm a fan of Pikasprey's softlock picking videos!
It doesn't have to do with "too much" junk data, unless I'm misunderstanding what you mean - the junk data the Mew trick relies on is always the same amount of data stored in the same locations. The problem here is that when Pikasprey battles a second trainer on the route that's already set to the "Start trainer battle" meta-map script, the game attempts to increment the current meta-map script ID again, which puts the script ID out of sync with what it's expected to be (both because it increments when you initiate the battle and because this sets the last text box ID you looked at to a trainer's pre-battle dialogue, which then triggers a battle with that trainer again after you black out), and the route ends up on an invalid script ID that does not point to a real meta-map script but instead to some other location in memory. When whatever data is in the location that points to gets executed as if it were a meta-map script, it can have any number of glitchy effects; on this particular route, it seems, it'll overwrite the memory locations holding the third item in your inventory and the amount of the second item in your inventory to the same set values (the item ID of the Dragon Rage TM and 7, respectively).
There's a YouTuber who specializes in turning Gen 1-3 save files into extremely elaborate horror-movie-level softlocks, and within the past day, they managed to combine Oversights #1-3 from this writeup, along with a lesser-known effect from 1 and 2 on the sea route that leads from Fuschia to Cinnabar. That allows the player to overwrite any items, including key items, with TM23 Dragon Rage, as long as the item to be overwritten is the third item in the bag.
It seems to be the result of the game being forced to create so much junk data that there isn't enough room to simply recycle it into one-time encounter data. When that happens, the game's next option is to dump that overflow over your item bag's memory, which results in item #2 getting multiplied by 7, and item #3 getting replaced with a bit of code that's then interpreted as TM23: https://www.youtube.com/watch?v=8f9DoruByBE
At first, when I watched it, I assumed that the softlock would rely on Oversight #4 in your analysis to remove the required items for challenging the Cinnabar and Saffron Gyms from the map, but nope, this softlock relies on actually pocketing the items and creating so much overflow data that the game's backup option is to fill the wild-encounter data (which is then removed when the encounter is sprung on the player), and into and over your item bag data and the sea route's data (which is far more permanent).
It's honestly amazing how these glitches are still being found 30 years after the games' initial releases, and I keep coming back to this writeup as a result, because you did an amazing job of showing both the coding side of it, the programmers' oversights and thinking, how this trick was discovered, and how it was initially dismissed, and it gives a very complete picture of the trick. Please keep up the awesome work! :)
You're right; I was thinking of some other glitch that existed in both.
I'm not super well-versed in the history of glitches in Japan, but I think the major glitch that got really famous in Japan was the select button glitch, which was fixed in Yellow and all localizations, and I'm pretty sure that can result in glitch Pokémon, so my assumption would be if the Old Man glitch wasn't available there, that's probably how Japanese players would have gotten to know Missingno. and company.
"and in Red and Blue (and their Japanese counterparts)"
Not to be nitpicky a whole 10 months later, but from what I've read (e.g. https://glitchcity.wiki/wiki/Old_man_glitch#Compatibility and https://github.com/pret/pokered/wiki/Left-Shore-can-spawn-Pok%C3%A9mon ), it sounds like the coast glitch actually didn't exist in the Japanese Red, Green, or Blue versions, and it was an error introduced in the localization process (and then fixed again in all versions of Yellow).
That said, now I'm wondering how Japanese players discovered MissingNo., and also how such a non-text-related bug could've been introduced in localization…
Ugh, thanks for letting me know. I had no idea.
all that aside, it's absolutely incredible to see both the users who popularized the mew trick show up on this forum over 20 years later! especially as someone who's been checking in on this site every once and a while for some ~8ish years (pales in comparison, but still) and am always happy to see it's still being updated, being a fan of pokemon games and all their weird bugs and quirks is something you can never really fully lose interest in and i think that's wonderful
was trying to figure out what that acronym even meant and doing a little digging it's a transphobic nazi dogwhistle. just wonderful (intense sarcasm)
butterfree, if you see this, i strongly suggest deleting the comment above, as it happens to be hate speech disguised on a surface level as support.
and to any trans women or queer people in general who stumble across the above comment and get caught off guard like i was. you are loved. above commenter is a bigot trying to bait people. take my hand. let's hit them with hammers together
So cool! I was never aware of this before, and you explained it so well!
Thanks for this post; this is probably my favourite glitch in all video games. It's awesome how it lets you catch all pokes including some glitch mons. It's awesome how it lets you fight glitch trainers and rosters (Prof Oak included, although it's tricky to get a high enough special stat, need to use the ditto trick). It's awesome how speedrunners use a variant where you faint to a wild pokemon in front of a trainer to trigger a similar effect to be able to beat the game in under 12 minutes. It's awesome how much it seems like a fanciful rumour yet somehow actually works.
First off, great job with writing this up. I was under the impression that the 2ch thread was the original but it seems it doesn't match up timeline wise. It's unknown if they saw that 2002 cheats page in English, but I highly doubt it. I think they might have discovered it on their own, and they didn't even write it up as a method to get Mew.
I think it's just incredibly strange that it got discovered in 2002, considering that at the time Crystal was the newest game out in the US, and Japan was about to get Ruby and Sapphire. Think about how often old games would get played back then, and it's even stranger it wouldn't have been found around 1999, and 2000 when it's popularity was at its peak. Pokemon definitely felt like it had a decline in interest after Crystal in my opinion.
However, despite all of that, I read there was another person in Japan that discovered the glitch on their own and called it the special encounter glitch. I think it eventually would have been found out, and it was only matter of time. It's just a shame that Gen 3 blocked off any connectivity with Gen 1 and Gen 2 which put a big damper on the impact of this discovery.
You may not have been the person to catapult the Mew trick into prominence, but you were the person who made me aware of it – when you posted it on the Mew's Hangout forums. Surely that counts for something.
It's pretty interesting, actually! The tiles on that coast (as well as the east coast of Seafoam Islands) are land on the left and water on the right, and in Red and Blue (and their Japanese counterparts), there's a small oversight that means it checks the right side to determine if this tile should have wild Pokémon encounters (there are always wild Pokémon encounters on water tiles) but the left side to determine what type of encounter should happen there. Since the left side of these tiles is land, those tiles are therefore defined as having land encounters instead of water encounters!
However, there are no land encounters defined for Cinnabar Island or Seafoam Islands or the water routes, so the bit of memory that stores the land encounters for the current area doesn't get set to anything when you enter those areas. Instead, like with some bits of the Mew trick, whatever data happens to have already been in that bit of memory previously will still be there, and the wild Pokémon encounters generated on those tiles will be based on that. If you were previously in an area with land encounters, such as the Safari Zone, then it will use that encounter data - only since you're no longer in the Safari Zone, you will be able to battle those Pokémon normally!
As for Missingno., that happens because when you speak to the old man who teaches you how to catch Pokémon, the game has to temporarily replace your name and back sprite with the old man's to show the simulated battle… but once that's done, it needs to put your name and back sprite back to normal. So, while the catching tutorial is happening, the game temporarily stores your name elsewhere in memory so that it can then copy it back over from there afterwards. And as it happens - much like in the Mew trick - the game will sometimes cheerfully use the same bit of memory for multiple unrelated purposes. In this case, your name gets temporarily stored in the same place it stores land encounter data - the programmers assumed that'd be fine, because there are no Pokémon encounters in Viridian City, and whenever you enter an area that does have Pokémon encounters, it'd copy over the correct data for that location first.
So, much like in the Mew trick, you've got two unrelated little programming oversights that come together: your name gets stored where the land encounter data is, and then if you go Surf on the coast of Cinnabar Island without visiting any locations with actual land encounters in between, the game will try to generate encounters based on the data that's still there, which now isn't actually Pokémon encounter data at all, but the numbers that stand for the letters in your name. Some of the characters in your name may correspond to actual Pokémon; others will correspond to Missingno. or 'M.
Missingno, safari zone mons… What is wrong with that coast?
This was very engaging read. It captured the feeling of how the trick's discovering and spreading could have gone. I felt like I was there.
I remember watching all the videos about Pokemon rumors last decade, before Pokemon Sun & Moon etc. finding the stuff about older games more fascinating. This post has a similar vibe, but it's based on real events.
My frustration with fake videogame tricks came from a post about there being a shot gun in Zombies ate my neighbours in Snes. It told, what level it was supposed to be, but I found nothing. I played the game emulated, so atleast I could use save state.
Facepalm
Scyther, apparently
Hello, your favorite Pokémon is Scyther, what's yours?
What an amazing read! I had never heard of this glitch before, and particularly enjoyed the explanation of how it works. Your writing has a nice narrative flow. I'll keep an eye on this site in the future for more from you..!!
0.00001190929
Aww - thanks anyway, though! Made the pronoun change yesterday and I gave it an extra read today to make sure I didn't miss any, but let me know if you spot anything.
Thank you so much again for commenting - I really hoped you would one day get to read my little tribute to what an important and fascinating little part you played in Pokémon fandom history, and I'm so glad to know you did. It absolutely made my week. Hope you're having a good Easter!
circuit
Mixpert
circuitIn response to: (deleted post)
Human_Bean
dubitable
8647
Chris
Elsum
Saku
Rotom-Wash