Mew glitch: Difference between revisions

The Mew glitch works by exploiting a separate glitch called the Trainer-Fly glitch.  The Trainer-Fly glitch is caused by encountering a Trainer that can battle the player at any point in the Trainer's line of sight and escaping from them.  These Trainers are nicknamed "Long-Range Trainers" due to the long distance that they can spot the player being defined as the maximum allowed by the game and will spot the player the moment that they appear on screen in the Trainer's line of sight.  When the game draws any NPC on the screen, that NPC is first placed in their default direction (south) for one frame, before being updated to face their correct direction. For Long-Range Trainers, this causes their line of sight to point south for the first frame, before correcting to their intended direction. For that first frame, the player can still bring up the start menu and use any [[Field move]] or items from their bag.  If the player uses {{m|Fly}} or a similar move or item, then the player will be spotted by the Long-Range Trainer before the player flies away from them.  This causes the game to believe that the player is starting a battle when they are actually not, causing various values to be read improperly and creating the core of the glitch.

The player must then battle a Trainer (not just a wild Pokémon) in between the escape and the final encounter, otherwise no encounter will appear. This is because the game initially expects the player to be spotted by the Long-Range Trainer and 'start' a Trainer battle.  For this reason, the player must 'finish' a battle with any Trainer before the game can begin behaving properly.  Additionally, this Trainer must walk up to the player (have at least 1 tile in between the player and trainer); he/she cannot be talked to directly or walked immediately in front of to initiate the battle, or the game will [[game freeze|soft lock]].  This is because the game believes that the player is about to battle the Long-Range Trainer that was escaped from and attempts to have the sprite of the Trainer walk up to the player.  If there is no space for the sprite to walk up to, then the game gets stuck in a loop that prevents the battle from occurring and the player from regaining control.

Afterwards, the player will regain full control and be able to access the menu at will.  Should the player return to the same location or floor as the Long-Range Trainer, the menu will pop back up as the game believes that the player has yet to close the menu in the location. After closing the menu, the game will immediately start a battle due to the game believing that the player has yet to enter a battle and ends up generating a battle with a wild Pokémon based on the Special stat of the Pokémon last battled and at a level based on the attack stage modifier of the Pokémon last battled.

For the Mew Glitch, the reason why Mew specifically appears at the end is based on the relationship between its [[index number]], which is 21, and the {{stat|Special}} stat of the Pokémon last battled. In both of the above cases, the Youngster's level 17 Slowpoke and the Swimmer's level 16 {{p|Shellder}}, the last Pokémon in their respective parties, have a Special stat of 21.

After battling the Youngster, the previously disabled buttons will now work again. The player must now return to Route 8 (with the most convenient method being Flying to [[Lavender Town]] and heading west). Upon entering the Route, the start menu will appear by itself; closing the menu will immediately begin a battle with a wild Level 7 Mew.

If the game is saved and reset during the glitch, or the player returns to Route 8 after Flying but before battling, or if any battle occurs or any NPC is interacted with between the time of the Youngster battle and the Mew encounter, then the glitch will not work and the game must be reset to before Flying from the Gambler.

As it is easily possible for one's Special stat to exceed 190, the highest index number of a valid Pokémon, the Ditto glitch allows easy access to several [[glitch Pokémon]] for Special stats of 191 or higher. For example, in Red/Blue, a Special stat of 198 will lead to battling a [[ゥL ゥM 4]]. If the Special stat is between 200 and 255, the player will instead battle a [[glitch Trainer]] instead of a wild Pokémon. It is even possible to battle [[Professor Oak]] in this way. Some Special stats (namely [[Jacred|200]] and 248-255) correspond to invalid [[Trainer class]]es and may lead to the memory-corrupting [[ZZAZZ glitch]] depending on the level/roster value (which defaults to 7; see [[:#Level and roster manipulation|level and roster manipulation]]). As the ZZAZZ glitch can be hazardous to the [[save]] file, performing the Ditto glitch with these Special stats should be avoided.

This can be also one of the side-effects of the Mew glitch If the player causes a text box to pop up before returning to the area where the long-range Trainer was escaped from, such as by talking to a NPC or reading a sign, then something other than the start menu will pop up at the end of the glitch. This is typically dialogue from Trainers on the route, which may be followed by a wild Pokémon battle, after which the player will no longer be able to move.{{fact}} Alternately, the text may be from interacting with a sign or an item; in the latter case, the item will appear in the player's inventory and disappear from the route as if they had picked it up normally. This may also allow the player to obtain items which are not currently on the route. Finally, instead of a text box, the player may trigger other glitches, such as [[glitch song]]s or [[0 ERROR]].

To remedy this, after escaping the long-range Trainer, the player must visit a PC and save the game indirectly by switching boxes. (The A and B buttons remain functional for the PC.) After saving, the player must reset the game. This makes the Start, A, and B buttons functional again.

* As implied above, the player can now defeat the entire [[Elite Four]] and {{pkmn|Champion}}. This will count as a Trainer battle, and the player can then return to the area of the first long-range Trainer to complete the glitch.

* As the above method is tedious, a much simpler alternate method is to simply go to [[Pewter City]] and talk to the NPC who brings the player to the Museum (the player must choose No to his question, so he will actually walk the player there). This will count as a battle being initiate. However, the player must encounter a Pokémon after this to get an actual Special stat loaded into memory. The Start menu must also be flashed after this, to prevent a possible text box error (see above).

* As the Museum person is vulnerable to the Snorlax skip glitch side effect (see above), the above method may fail to work after being used once. An even simpler alternate method is to simply push any [[Strength]] boulder, which  will count as a battle being initiate. (No other [[HM]]s behave this way as none of them move sprites or objects.)

{{Incomplete|section|Describe why all of the above actually work; see http://forums.glitchcity.info/index.php/topic,7365.0.html. For the same reason, losing to the second Trainer (see below) works but losing to the Elite Four or Champion does not.}}

Note that as long as the player has at least one undefeated Trainer in a different area than the long-range Trainer, they can avoid having to do any of the above indefinitely. It is not necessary to defeat another Trainer after escaping, only battle one, so a player can deliberately lose to a Trainer and continue on with the glitch, and that Trainer will remain battleable. However, if the player loses to that Trainer and then goes back to the area of the long-range Trainer and battles a Pokémon with this glitch, the long-range Trainer will no longer be battleable.