Exploring the Mew Glitch

In this video we explore the long range trainer glitch, or, as it's more widely known, the Mew glitch! This glitch allows us to catch mew on the original Pokemon Generation 1 games for the Game Boy.

Fyi, this is not the quickest way to catch mew - the trainer to the west of the nugget bridge can be access much earlier in the game and is the easiest & quickest way! I used this specific trainer because it was (as far as I can tell) the "first" version of this glitch that was discovered :)

Checkout the other videos from our series:

To clarify the engaged trainer class, as there were some comments about it: During the fight against Youngster, the byte "engaged trainer class" is used as the second byte of Slowpokes special stat. It's a 16 bit value, so at 7:55 you can see that it's 0x0015. As we go back to route 8, DisplayEnemyTrainerTextAndStartBattle however uses this value as "engaged trainer class". So the second byte of the special stat of Slowpoke sets what Pokemon/Trainer we will see when we go back to i.e. route 8. If it's over 200, it will engage a trainer, if it's under 200, it will engage a Pokemon. And the Pokemon we are encountering is the one with the ID in "Engaged Trainer Class" at that moment - Mew.

Links:

[LadBooboo]

Y'know what I find weird? That "Mew is under the Truck" thing was universal for people who played 1st gen no matter where in the world.

[theykeeponrising]

FYI - this is much easier to do if you use the trainer in the grass west of the nugget bridge as the "long range trainer". This way you can get Mew anytime after beating the nugget bridge. You can also catch Abra for Teleport instead of using Escape Rope or other abilities that are either later in the game or consumes a TM.

[gameglitcher]

Never had a gameboy but i still enjoy seeing how all of this stuff comes together, and inherently falls apart.

[TheEvilRayquaza]

its also really neat how the trainer with the slowpoke isnt the only trainer who can make Mew spawn. One of the trainers in the middle route 7 also spawns one, as well as a trainer in (if i recall) Cerulean Gym. So if y'all want to play the game with 3 Mews easily, there you go.

[vitorfray]

Just tried it out in an actual Gameboy with Pokémon Blue. It worked, and the save file was fine and dandy! :)

Thanks felow uploader, this was sort of a childhood dream of mine!

[AmyraCarter]

I imagine that someone was playing this, came across a trainer they wanted to avoid, and so, spammed the start button, and then flew away, then decided to face a different trainer, then after all that, went back to the route, and blammo, there was Mew. Of course, that's just one theory. Who knows, really, lolz

[Arisius]

I thought you would have included an explanation on 'why' the Mew (or other Pokemon) are at Level 7. The "7" is the result of whatever Attack Modifier was in the previous battle. The default is 0 out of -6 or +6 (which is 7). For example; If you used Growl once on the previous fight, the Mew Glitch encounter will be Level 6. If you encounter one at Level 1 and then give it EXP under the next level-up requirement, the experience points cap out, giving you a Level 100 immediately. This means you can get a Level 100 Pokemon before fighting Brock in Pokemon Yellow.

[jugarnaut]

For anyone playing on a cartridge and you've beat all the long range trainers, you can still do the glitch. Just need to do the safari zone glitch, fight the elite four, and make sure you count your steps before lance. Make sure you ding back to the safari zone during the scripted walk into lances room and you'll get the exact same setup as just flying away from a long range trainer.

[spiritcore]

I really like your Gameboy series with LiveOverflow.
Takes me back to my childhood.

[ZorotheGallade]

The thumbnail just screams:

"Oh, you're approaching me?"
"I can't store an internal variable in the game's memory to manipulate the species and level of Pokémon that appear upon a random encounter that's stored in reserve without getting closer."
"Oho, then come as close as you like"

[ktvx.]

What amuses me is how the game when a variable in memory is invalid or something like an index goes out of range, it just does a completely unexpected thing instead of crashing

[bruhintoshmoment]

Truly awesome! It's so satisfying to see how such games actually worked and what tricks they used to save memory. Very nice video!

[SB-SB]

24 in games hours??? Lol I probably spent 24 in game hours getting through that damn cave without flash.

[finn]

Nice explanation and I think this confirms, that the Mew Glitch was just an accident/programming error and not a GameFreak secret. It's really funny that all those little code mishaps led to the only way to acquire Mew :)

[archibaldtuttle]

I've been curious about a function in the Trainer Fly glitch that I've stumbled across a couple of times.

When using the hex code 249 instead of the desired code for Mew, you fight someone who I think may be a version of Blue or P. Oak who uses a team including Missingno., Rhyhorn, Lapras, and another strange glitch pokemon. When I battle this character at the end of the TFG and sequence the deaths of the pokemon properly I end up with the trainer appearing and releasing a series of game related noises for up to half an hour. They mostly cycle between the Rhyhorn growl and the Fly jingle at slightly irregular intervals. I'm fascinated why, I'm assuming I managed to link the trainer's success jingle with the overflow information from performing the glitch and the sound files have started reading from the wrong area like a hex code acid trip.

[ThomazSDA]

Interesting. Very interesting! I've known about the glitch for as long as I can remember, but never knew WHY it worked. Thank you very much for this thorough explanation. :)

[eicas_]

This is one of the most believably accidentally found glitches. I might even had found it if I had played Gen 1, seeing as I hate trainer battles

[TheForeverRanger]

BTW you can get Mew as soon as you get past Nugget Bridge. Just need to avoid the trainer in the grass so you can catch Abra. After you catch Abra, perform the trainer glitch with that trainer you avoided and use Abra's teleport. Then battle either the Slowpoke trainer OR the Lass in Misty's gym with the Shelder.

[Bernazepam]

You can actually do this glitch as soon as you get to cerulean city anfrer beating the bridge rocket team member, just head to the left and catch an abra (dont fight the trainer in the grass) save and then proceed to walk down directly to the trainer and open the menu and use teleport as soon as he notices you (you have a few frames to do it right) after that go and fight the trainer and then go back walking to the bridge and mew will appear

[sirswagabadha]

I remember finding out about this glitch and going absolutely crazy with it. I think I had a nearly filled up pokedex before I even got my 8 badges. Then I combined this with a few other glitches in yellow to face brock with a team of a level 100 venusaur, a gengar, and an exeggutor. I miss the days when games were this broken for those who improvised. No fly or teleport to be found that early in the game, so I had to use escape ropes in mt. moon and viridian forest on two specific trainers who allow this to happen anyway