7. Luigi Is Mario's Twin Brother Because Of NES Memory Limitations (And That's Why He's Green, Too)
When we think of Mario, we usually think of Luigi, too, though Mario's older, lankier brother hasn't had it quite as easy as his sibling. Nintendo themselves have even adressed this from time to time, making coy references to Luigi's status as "a lesser Mario brother." Still, the green-clad plumber has his fair share of fans - fans who might not appreciate that only Luigi exists as Mario's twin because of the NES' memory limitations. Seriously: Luigi is who he is because there was simply no other choice but to make him that way. Due to the limitations of the NES, it was impossible to generate a player for a second character that didn't look like the Mario character. So the designers had to settle for cloning Mario and making him green. They then decided to brand them both as "brothers," because that gave a natural explanation as to why they looked exactly the same.