A new story idea every single day.
Ideas can be shit, detailed, loose, tight, scenario-based, character-based, or could just be a single line of dialogue which might later unfurl itself into a glorious tendril of butt-tickling wonder-magic … or something.
Stole this concept from @ryanklindsay.
Check out the previous ideas here.
A curse is placed on a writer. He must come up with a new story idea every single day. If he fails he will never have a new idea for a story ever again.