In the days before the internet, urban legends and straight-up hoaxes spread like wildfire, thanks to an overeager willingness to believe anything and nothing to keep the rumors in check. There was no one to deny the existence of wild claims like bringing dead characters back to life, with the exception of a few gaming magazines (such as EGM, which - as you'll see - often perpetuated the hoaxes themselves). And when they turned out to be untrue lies, the harsh reality of our crushed dreams stung. But you know what stung more? TRYING TO BEAT MORTAL KOMBAT 100 TIMES IN A ROW WITHOUT SUFFERING ANY DAMAGE IN ORDER TO UNLOCK THE SONYA BLADE NUDE CODE. Ahem. These are the 6 cruelest hoaxes and urban legends in videogame history.
Mario and Luigi go together like spaghetti and meatballs, like donuts and coffee, like mushrooms and fire flowers - so it wasn't unreasonable to assume Luigi would be a playable character in Mario's first foray into the 3rd dimension. Sure, Nintendo had specifically said it was a single-player affair, but that didn't mean whoever was playing couldn't choose between Mario and Luigi, right? Why would Nintendo leave its 2nd most recognizable plumber out of the game entirely, when even Yoshi makes an appearance?
That was the attitude the internet seized upon at the release of Super Mario 64 (note it wasn't "Super Mario Brothers 64"). Luigi had to be there somewhere. Why would Mario leave his taller, weirder brother behind? The first "clue" the internet found was "L IS REAL 2041" (or something like that) illegibly scrawled on a statue: somehow, this meant Luigi was real and in the game (other theories included promotion for Paper Mario). Coming in with the assist were numerous texture hacks, photoshopped screenshots, and tales of playing as the green plumber flooding the internet.
Shockingly, he was not in the game. But then Nintendo released the Super Mario 64 remake for the DS and he was included - along with Yoshi and Wario. It'd be nice if every rumor was eventually validated with a handheld remake.
In most Legend of Zelda games, you get the Triforce at some juncture. That's kind of the point of most of the games - it's the big MacGuffin you're after the whole time. Sure, you want to save Zelda and defeat Ganon, but the real goal is reuniting the Triforce and restoring order to the world.
Supporting this was an early trailer that actually showed Link getting the Triforce. That settled it. Nevermind that videogame companies can and do change their games significantly between early trailers and the ultimate release. Of course, Nintendo did remove the "getting the Triforce" thing from Ocarina of Time. And, as with most of these hoaxes, the rumor mill had a way of still getting it, and of course it was needlessly and hopelessly complex.
That was the beauty of these rumors, and what allowed them to spread so widely: they were so difficult that most people would never attempt them, and (if they did) they were often too demanding to be accomplished. Therefore people would assume they screwed up something in the delicate procedure and try again and again. The requirements of this one had you running around all of Hyrule, doing weird, vague, and pointless tasks, and getting nothing in return.
If we only would have had the Triforce of Wisdom to begin with, we may have seen through this dumb hoax.
As gamers grow older and more suspicious, the rumors need to get more difficult to debunk. We live in an age where the rumor birth/death cycle happens months before a game is even released. So - the Fallout 3 morse code rumor. Each Fallout game has been filled with obscure references and secret Easter Eggs that are still only now being discovered, so a lot of people were ready to believe strange morse code messages might be real in Fallout 3 - even if they were predicting the future.
If you killed Three-Dog and completed the game through the destruction of Raven Rock, Galaxy News Radio would occasionally turn to a "numbers station" (think Lost) followed by morse code messages.
The creepier interpretations of these involve the exact date of the Queen of England's death, Britney Spears winning an Oscar, and someone rambling about the end of the world. What gave these messages credence were some other supposed decoded messages - predicting Gary Coleman's death and the BP Gulf oil spill. The real advantage of this hoax was that the messages were hard to come by, and even if you could find some, most gamers can't easily interpret morse code transmissions. So instead, our instinct was to trust the internet. Internet rumors...internet rumors never change.