The document discusses several common conventions and tropes found across different subgenres of horror films, including slashers, supernatural films, possession movies, and Gothic horror. For slashers, it notes they usually involve a masked killer murdering a group of teenage transgressors one by one, until the "final girl" defeats them. Supernatural films center around an evil spirit that causes increasing terror. Possession movies similarly involve demons possessing victims. Gothic horror films feature mythical monsters in dark, gloomy settings of the past where a male protagonist saves a female in distress.