From the introduction:
Welcome to Imp of the Perverse. This game invites you and your friends to enter a Jacksonian Gothic America where dark passions pierce the all-too-thin Shroud over the land of the dead, rending holes through which monsters arise, seeking satisfaction of their perverse desires. Using pencils, paper, dice, and your shared imagination, you shall compose compelling tales of horror as your protagonists hunt down the very real monsters that plague their mortal world. Each protagonist is an inhabitant of this Gothic rendition of the historical Jacksonian period in America, and each bears an Imp of the Perverse on their own shoulder. Birthed from their particular untameable urges and compelling them to commit terrible deeds, only by fighting those who have given in to their own Imps can the protagonists gain redemption. They are tempted to embrace their own perversity, for it contains great power, and it takes much to banish monsters beyond the Shroud between the worlds of the living and of the dead. The question before you: can you resist the seductive draw of your own perversity long enough to regain your humanity—or will you embrace your Imp and become damned?