The rules are:
It must be Cicada-themed
You can't use any part of the book cover art
It's open to international contestants
The deadline is June 30th, so you'll have time to read Cicada and have an idea of what the book's about
The winner will receive the t-shirt you've designed, and your design will be made available in the online store that I'll be opening up later this summer.
Send your designs to firstname.lastname@example.org
Good luck and have fun!