Closed menu Select glitch

Please note that this article refers to glitches which only exist in the Japanese versions of the specified Pokémon game, or refers to glitches from games which were only released in Japan. These glitches do not exist in other translations of the game.

Closed menu Select glitches are a division of Select glitches in Pokémon Red, Green, and Pokémon Blue (Japanese). Examples of closed menu Select glitches include the dokokashira door glitch, fossil conversion glitch and Trainer mutation glitch.

These are the Select glitches that are accessible by pressing B on the item or PC item inventories and later bringing up the Pokémon menu via a battle, the Lavender Town Name Rater or Pokémon Day Care Center man.

When the Select button is held down on a bag or PC item, the game writes to memory address CC35 which is a value for the list entry number highlighted. Due to an oversight, the game does not clear the value after the menu is closed with B, allowing the player to swap entries beyond the end of the list. For example, pressing Select on Bag item 10 from the overworld, exiting with B, B and entering a battle will allow the player to swap Pokémon 10 with a Pokémon of their choice and cause memory corruption, even if less than 10 Pokémon were in the party.

This glitch functions differently between the original revisions of the Japanese ROM (collectively one revision due to no game code/data changes), and the later revisions (also collectively one revision due to no game code/data changes). In the original revisions, any changes to CC35 (select button held down) are kept after closing the in-battle menu, allowing for the partial switch glitch to occur within a Pokémon battle. In the later revisions, changes to CC35 are lost after closing the in-battle menu (making the partial switch glitch impossible), however, the glitch can still be exploited if it is set up from the inventory menu and carried forward into the party menu from a Pokémon battle, the Day Care man, or the Name Rater.

The equivalent Select glitches can be simulated with the expanded party or a no expanded party international Select glitching method (minus ones involving moves beyond slot 4).

Method 1*

1. Enter battle
2. Open the Bag
3. Highlight an item with 'Select'
4. Close menu with B
5. Access the party menu
6. Press A on a Pokémon, or moves list (press Select on a move)

(*): Revision differences (detailed above) apply. Impossible on v1.1 releases.

Method 2/3/4

1. Open the Start menu
2. Open the Bag
3. Highlight an item with 'Select'
4. Close both menus with B, B.
5. Enter battle, talk to the Day Care man, or talk to the Name Rater to access the party menu.
6. Press A on a Pokémon

Select glitch workaround

Due to zero maximum HP glitch or possibly another complication; a Select glitch may sometimes lock up the game after the swap. A solution is to simply have an アネﾞデパミﾞ (FF) in the party above the position the player is trying to swap; as this hides details like the HP bar.

Trivia

According to Pokémon Lab (a no longer existing Japanese glitch, datamining and hacking website from 1997), method 2 was actually a discovery by a user called noborukun, which raises a question if very early in glitching history this glitch was thought to be exclusive to the v1.0 version (assuming the community was aware of revision differences); as method 1 is impossible on v1.1 releases.