Literally, "bad place." Use for works that are accounts of imaginary worlds, usually in the future, in which present tendencies, beliefs, principles, or theories are carried out to their intensely unpleasant culmination. Examples include George Orwell's 1984 and Aldous Huxley's Brave new world.
Use for works of the gruesome and horrific. Themes can include possession; people or creatures rising from the dead; and characters with psychic or occult powers. Examples include Stephen King's Shining and W.W. Jacobs' Monkey's paw.
Use for works dealing with witchcraft, spiritualism, psychic phenomena, voodooism, etc., and for works dealing with the mysterious or secret knowledge and power supposedly attainable only through these and other magical or supernatural means.
Use for works of fantasy that deal with possible though not necessarily probable events and are based approximately on scientific principles, e.g. space travel, time travel, etc. Use also for works in which mankind confronts alien cultures or environments. For works that deal with non-existent, incredible, or unreal worlds, characters, and physical principles, use Fantasy fiction.
