From the introduction:
The game of Hoarfrost revolves around a group of mundane characters facing otherworldly horror in self-contained short stories of desperation and fortitude. These tales depict regular people who inadvertently uncover an unspeakable mystery and try to save themselves, if anything. Most of the time, the stories end in tragedy. Hoarfrost emphasises creative storytelling involving all participants
Each story (Play) requires one game master (Seer) as well as one or more players who take control of player characters (Partakers) and takes from 1 to 3 hours to finish. Every story should be played in its entirety in one sitting. If you so desire, you may tell more than one Play during a game session.
Remember to always finish an already started Play.