The Blue Box is an expansion to Cards Against Humanity.
Comes with 300 fresh cards to mix into your game (220 white and 80 black).
Contains the same cards that used to be in the Fourth, Fifth, and Sixth Expansions.
Red Box not required, though heartily recommended.
Allows you to eat anything you want without gaining any weight.
The Blue Box contains 300 cards you can add to your deck of Cards Against Humanity, allowing you to eat whatever you want without gaining any weight.