The effects of the MISSINGNO. glitch in Pokemon Red and Blue have well-documented at many sources. Encountering MISSINGNO. corrupts Hall of Fame data, causes temporary graphics glitches, and sets the most-significant bit of the 6th item in the player's inventory.
That said, there are also a lot of rumors about MISSINGNO. and its origins. There are many sites online that claim that MISSINGNO. can delete saved game files, but I've yet to find any actual verifiable claims that support this.
Are there any verifiable reports of MISSINGNO. actually deleting saved game files or otherwise rendering an existing save file unusable? Or is this just another urban legend?
Thanks!
Best Answer
As directly quoted from the MissingNo. page on Bulbapedia:
Nintendo has an official description of Missingno. listed in their Customer Service troubleshooting section. A direct Nintendo quote:
TL;DR: No, it just messes with your save files, permanently messing them up, but not actually deleting them.