Writing genres are categories that distinguish literature based on some set of stylistic criteria. Sharing literary conventions, they typically consist of similarities in theme/topic, style, tropes, and storytelling devices; common settings and character types; and/or formulaic patterns of character interactions and events, and an overall predictable form. Urban fantasy is a subgenre of fantasy, placing supernatural elements in an approximation of a contemporary urban setting. Detective fiction is a subgenre of crime fiction and mystery fiction in which an investigator or a detective investigates a crime. Political thriller is a thriller that is set against the backdrop of a political power struggle, high stakes and suspense are the core of the story.