Pokemon Deleted

Not that I know of, no. Though I've always warned anyone who decides to play my game that they can start a new game, just not save it over mine.

I don't give my games to other people to play so I don't have this problem. :x

When I borrowed my cousin's copy of Yellow a bajillion years ago, I just continued on with his save file, and managed to beat the Elite Four and catch Mewtwo for him. Then somehow my sister got a hold of my Game Boy, started up a new save file, and overwrote the data after she got bored of playing for like 10 minutes. She would've only been 4 or 5 at the time, so I'm surprised she managed to do that, but both of us were still pissed after all the effort we put into that save.

well, there was that mysterious time. i was playing firered for the first time and i actually picked bulbasaur and i was at pewter city. took a break and laid down my gba. turned off and all. i was at the house and a bunch of my cousins and my sister was there. i opened my gba and somehow i was at viridian city with a charmander and a female sprite. oddly enough, all the cousins at home were boys. the only two girls at home back then was my mother and my sister. i asked my sister if she played, but she said she was with mom the whole time, helping her cook. and mom confirmed.

in the end, i figured out it must be one of my cousins or something. didn't really mind it since i wanted squirtle over bulbasaur anyway

Nope. Nobody else ever plays on my copies of the games. Although I have traded a few Pokémon online that I used to use, so I don't know if they still exist or not.

I have had my file deleted two times. First time I don't know how it got deleted but I'm guessing a classmate took my Gameboy out of my backpack when I was out of the classroom and deleted it and the second time my file got deleted was when a classmate wanted a Squirtle. He started a new file on my Blue version so that he could trade Squirtle to his Silver version but in order to trade, you have to save first and that's how I lost all my lvl 100 Pokemon.

No, of course not. No one but me is allowed to touch my Pokemon games.