Ralph gets fed up with being a villain, leaves his game through the power cord, and goes on a wacky, misadventure-filled romp through rip-offs of other, more popular, video games while no doubt peppering the already lame Disney humor with video game jokes. He finds out from a character named Vanellope von Schweetz, in a world that's basically Candy Land mixed with Mario Cart, that her video game world is under peril by something that Ralph may be responsible for.

Which you already know is that an actually evil villain start thinking "Gee, if this 8-Nit piece of shit can escape into other games, I'll do it too!" and then you have Harbinger from Mass Effect or Satan from Dante's Inferno attempting to hijack the Internet... which I'd honestly pay to go see, but this is Disney, so you already know what kind of villain you're actually going to get.

So Ralph decides he's going to save the video game world, and does so (the villain will probably die by falling off of something, because Disney sure loves their cut-and-paste plot formulas), all while learning to accept his place as a villain in his own game and decides to go home because it's "where he belongs" or some sappy shit like that, and nothing changes through any of this, because the world would end if Disney ever decides to do something actually unique. It's not like Pirates of the Caribbean was balls-out insanely popular in spite of being a Disney movie or anything.

So there. I just saved you about $7 that you would have spent on a movie ticket, or $12 if you're stupid enough to go see it in 3D.