This is something all wrimoers are a fan of or at least have participated in. Dares its a way you can challenge yours and your fellow writers creativity by daring you and others its great for eliminating writers block or just wanting to add some thing new to a story.
One example I've come across at the past wrimo is

I Dare you to have a man thats afraid of hair
extra points if he carries a razer around in his pocket
a cookie if he tries to shave someone else's hair

it can be as fun,complex and random as you want or it could be as simple as you want the dares are the length of your imagination which is boundless good luck i'll post a few below