Pokémon Red and Blue/Secrets: Difference between revisions

There are two vertical strips in the Pokémon world where very strange things happen. One is the east coast of [[../Cinnabar Island/]], and the other is the east coast of [[../Seafoam Island/]]. When you swim around on these thin strips, as close to land as possible, you can run into wild Pokémon from the last area you visited.

The area in the game's memory (RAM) holding the possible Pokémon you can currently encounter is also used as a buffer to hold other data during cutscenes. For example, the cutscene from the old guy in [[../Viridian City/]] who taught you how to use Poké Balls copies your name to this buffer. Since neither [[../Cinnabar Island/]] or [[../Seafoam Island/]] overwrites this area with wild Pokémon information, the cutscene data is read as Pokémon numbers (e.g. hex value 15 = Mew) and not all values are valid. The game already had debugging code from Pokémon Green/Red/Blue to cause all invalid Pokémon to be "Missing No.", which was not meant to be used and is thus glitchy in the remakes of Red/Blue. The seemingly random effects of "Missing No." are due to the debugging code reading/writing memory that it thinks are certain things (e.g. its own moves) but are actually something else (e.g. virtually anything else) because the memory structure is slightly changed.