From the Game's Introduction:
This is a game that will accommodate any number of players, but will likely work best with a smallish number; definitely not less than three, probably no more than five or six. To play, you must create a mask. The mask will be constructed from a single piece of letter sized white paper. Just draw two simple eyes – just circles about the size of quarters – about halfway down the page, so they're as far apart from each other as they are from the edges. The mouth will be a single straight line drawn about halfway between the eyes and one of the short edges, just straight across, as wide as the eyes are apart. Do not poke or cut out the eye holes. You don’t need to attach a string or rubber band to hold the mask on anyone's head – players will just hold the mask up in front of their faces when they want to use it.
Players take turns to wear the mask, assuming the shared persona of the mask's character whilst conversing with the other characters. At some point during the conversations, one person will be identified as wanting to harm the mask's character, and another person as wanting to help the mask's character.
When play has progressed sufficiently, the player currently controlling the mask's character may confront the person intending to harm them. The players collectively vote on which way the conflict should go, with the victor (the harmful or helpful person, depending on the results of the vote) narrating the final fate of the mask's character.