Monster Slayer is a cooperative storytelling game for 1-6 players about a group of people who fight monsters that come to their town. It allows you to tell your own stories like the shows Buffy, Supernatural, Grimm, and more. The game provides the plot elements of an episode of a monster slaying television show, but the story and tone are determined by the players.
It uses the Three Act Adventure system which defines the structure and rules of the game. The specific version of the game provides the questions used during the game, it provides the genre. You can use the same system with a different set of questions to tell a heroic fantasy, urban fantasy, whimsical, or other type of story.
Players take turns telling what happens based on the prompts determined by drawing cards from a standard poker deck. The prompts are generic enough that players can tell the story that they want to tell. They can reference existing elements already mentioned in the story or introduce new elements. While they should base their story on the prompts, they need not take the wording literally and can change details of the prompts to suit the story.