The key conventions in horror films include setting, technical elements, iconography, narrative, characters, themes, and music. Settings often involve isolated or creepy locations like forests, abandoned buildings, or graveyards. Technical elements like camera angles, lighting, and editing are used to build suspense and fear. Iconography may include dark colors, weapons, masks, and monsters. Narratives usually involve heroes embarking on a quest to defeat a threat like a killer, while teenagers are often victims. Characters include protagonists, villains, and police; themes commonly explore good vs evil, the supernatural, and madness. Music and sound effects enhance the scare factor.