From the back of the box:
"Once upon a time there was a little expansion deck. This deck was full of marvelous creatures and magical artifacts which, in responsible hands, could have been used to create wondrous tales of fantastic adventure.
However, these cards wound up in your hands instead, and you're a raving mad stupiduelist!
This 60 card expansion to Stupiduel can be used to turn your original deck into a pure fantasy deck, or just shuffled right in. Either way, your Stupiduel matches will be transformed by its powerful contents, allowing attacks that could only be dreamed of, defenses that could only be wished for, and conclusions that will leave you laughing happily ever after!"