From the publisher's website:
You and your friends have an evening free together. Normally you get together to roleplay, but your gamemaster doesn't have anything prepared. You could just hang out, or play some other kind of game, but you really want to roleplay. What can you do?
StoryCards is a roleplaying game that can be played from start to end in four hours, with no prior preparation. It uses a special deck of cards to inspire creativity, enabling you to create richly detailed characters and adventures in less than an hour, for any setting you can imagine. And it uses minimalistic, common-sense rules to keep the adventure moving quickly.