Unlike Fantasy, Supernatural Fiction and Science Fiction – terms which describe generic structures – horror is a term which describes an affect. A horror story makes its readers feel horror. There are two important distinctions to make, however.
Distinctions. Horror stories can be set in entirely mundane worlds and be simple exercises in sadism; this category of horror does not concern us. They can also be set in any of the regions of the Fantastic, though usually in the one we think of as the supernatural.
Second, what we are calling "pure" horror can be distinguished from stories which convey a sense of horror while continuing to fulfil other genre requirements. Fantasies which convey a sense of horror are better called Dark Fantasy, and supernatural fictions with a horror "feel" are better called Weird Fiction. Sf horror stories, which are relatively rare, boast no label in particular.
The shape of horror. A "pure" horror tale may occupy the same region as a supernatural fiction – this world is being encroached upon by another – but is shaped primarily to convey the affect of horror. Thus the "pure" horror story is normally structured so that its protagonist and its readers share the same reactions. This shared horror is evoked in the text through the joining of two simultaneous elements: the recognition of a threat to one's body and/or culture and/or world; and a sense that there is something inherently monstrous and wrong (see Wrongness) in the invasive presence.
Both are necessary for the affect of horror. It is not enough for the mundane world to be invaded, assaulted, seduced, taught or inveigled from another sphere, as generally happens in supernatural fiction; nor is it enough for Monsters to exist – as they often do in fantasy without threatening the fabric of the Otherworld. What generates the frisson of horror is an overwhelming sense that the invaders are obscenely, transgressively impure. The monsters of horror are befoulers of the boundaries that mark us off from the Other. Like Frankenstein's Monster, they may be neither one thing or another, so that they violate the decorum of species, of role, of fitness to place. They may be either suffocatingly too full of rotten being, like a fallen Angel or Dorian Gray; or they may represent a haemorrhage of joining, like Jekyll and Hyde, two distinct beings who are, as though by virtue of Trompe-L'oeil, obscenely one; or they may be manifestly incomplete, like the great majority of monsters in horror tales and Horror Movies. Especially when incomplete, they are ravenous, and will eat anything: the body and the Soul; the City and the state; the Fertility of the Land.
Many authors who are mainly known for horror also write fantasy, dark fantasy, supernatural fiction or weird fiction; those given entries in this encyclopedia include Scott Baker, Clive Barker, Charles Beaumont, E F Benson, Ambrose Bierce, William Peter Blatty, Robert Bloch, Poppy Z Brite, Ramsey Campbell, Nancy A Collins, August Derleth, Dennis Etchison, Charles L Grant, James Herbert, Stephen King, T E D Klein, Dean R Koontz, Sheridan Le Fanu, Matthew Lewis, Thomas Ligotti, Bentley Little, Frank Belknap Long, H P Lovecraft, Brian Lumley, Arthur Machen, Richard Matheson, Charles Robert Maturin, Edgar Allan Poe, Anne Rice, James Malcolm Rymer, Sarban, Dan Simmons, Peter Straub, Bram Stoker, Karl Edward Wagner, Donald Wandrei, Chet Williamson, J N Williamson and F Paul Wilson. [JC]
see also: Psychological Thriller.