Lovable Sulley and his wisecracking sidekick Mike Wazowski are the top scare team at Monsters, Inc., the scream-processing factory in Monstropolis. When a little girl named Boo wanders into their world, it's the monsters who are scared silly, and it's up to Sulley and Mike to keep her out of sight and get her back home.

Wreck-It Ralph is the 9-foot-tall, 643-pound villain of an arcade video game named Fix-It Felix Jr., in which the game's titular hero fixes buildings that Ralph destroys. Wanting to prove he can be a good guy and not just a villain, Ralph escapes his game and lands in Hero's Duty, a first-person shooter where he helps the game's hero battle against alien invaders. He later enters Sugar Rush, a kart racing game set on tracks made of candies, cookies and other sweets. There, Ralph meets Vanellope von Schweetz who has learned that her game is faced with a dire threat that could affect the entire arcade, and one that Ralph may have inadvertently started.