How to write horror

You want to write a story that scares someone, and the first decision is what that scare is made of. Wikipedia's article on horror fiction defines the genre as speculative fiction "intended to disturb, frighten, or scare an audience", and quotes J. A. Cuddon's fuller definition: fiction "which shocks, or even frightens the reader, or perhaps induces a feeling of repulsion or loathing". Fright, shock and loathing: the genre aims below the reasoning mind, at the reader's pulse, and every craft decision below exists in service of that one effect.

What makes horror work

The genre's most-quoted sentence is H. P. Lovecraft's: "The oldest and strongest emotion of mankind is fear, and the oldest and strongest kind of fear is fear of the unknown." Read it as a design instruction rather than a slogan. What the reader cannot see, cannot name and cannot predict does more work than a monster rendered in full detail, because the reader's imagination stocks the dark with something personally frightening.

The article's other tests agree. Darrell Schweitzer's is the bluntest: "a horror story is one that scares us", and it requires a sense of evil and menaces that are "truly menacing, life-destroying". Elizabeth Barrette's account of why readers enjoy the genre adds its purpose: the best horror intends to "rattle our cages and shake us out of our complacency". Two quieter elements do load-bearing work beside them. The first is atmosphere: the article describes horror's aim as creating "an eerie and frightening atmosphere for the reader", and atmosphere is built from specifics, weather, light, sound, the wrongness of an ordinary room. The second is the uncanny, the effect Freud traced to the familiar turning secret: everything unheimlich, in the line of Schelling's he quotes, is "that ought to have remained secret and hidden but has come to light". Jentsch's fictional device for producing it was to leave the reader uncertain "whether a particular figure in the story is a human being or an automaton". A figure that is almost human, a house that is both home and trap: these frighten because they are almost normal.

Dread, shock and disgust

Craft discussion keeps returning to three instruments, and it is worth knowing which one you are holding. Dread is the reader's certainty that something is coming, held long before it arrives. Shock is the arrival itself, the sudden violence of the reveal. Disgust is the residue, the loathing that lingers after the page is turned. (The tidy three-instrument split is craft consensus; the sourced spine is Ann Radcliffe's 1826 distinction between terror, the dread before an event, which "expands the soul and awakens the faculties", and horror, the revulsion after it, which "freezes and nearly annihilates them".) Noel Carroll's account adds a design condition: the menace must be threatening, physically, psychologically, socially, morally or spiritually, and impure, violating the categories a culture keeps tidy.

The monsters of the canon satisfy that test precisely. The article notes that horror's threats "often reflect broader cultural anxieties", and reads Dracula as a metaphor for repressed Victorian sexuality. Your monster will be read that way whether you plan it or not, so plan it.

The reader contract

Horror's subgenre labels are promises about where the scare comes from. The article names psychological horror and supernatural horror as the two main subgenres, and three of its named traditions have entries in this catalog's glossary:

• [Gothic fiction](/glossary/gothic-fiction) is the founding tradition: Walpole's The Castle of Otranto (1764) starts the line that runs through Radcliffe to Dracula. Castles, secrets, family curses, dread in old rooms.
• [Cosmic horror](/glossary/cosmic-horror) is Lovecraft's branch: the scare is scale, the discovery that humanity is irrelevant to something vast and indifferent.
• [Slasher](/glossary/slasher) is the bodily branch: pursuit, a killer, victims, endurance. The article traces the tradition's fiction to the era of the Manson Family murders.

Choose the shelf deliberately, because each audits a different nerve: the gothic reader audits atmosphere and secrets, the cosmic reader audits scale and futility, the slasher reader audits pursuit and survival.

Atmosphere and stakes

The stakes side of the contract comes straight from Schweitzer: the menace must be life-destroying, not inconvenient. Horror stakes are bodies, minds and souls, and once a wound is taken it must stay taken, because a genre that threatens real harm loses its authority the first time harm quietly resets. That is continuity work: track injuries, exhaustion and sanity across chapters the way hurt and comfort stakes demand. The threat itself is canon too. What the entity can do, what it cannot, what it has already taken and from whom: those facts are the dread's spine, and contradicting one retires the fear. A story bible that holds the threat's rules is what lets a monster stay frightening for a whole book.

Horror in web fiction

Horror was serialized before most genres had shelves: the article records The Phantom of the Opera appearing as a serial before its 1910 book publication, and its modern online examples are native to the web: the creepypasta tradition, Alex Hall's Ben Drowned, Kris Straub's Candle Cove. Serial form suits the genre, because dread is a clock and a release schedule is its metronome: the gap between chapters is part of the scare (see web serial release schedules). If your darkness runs toward cruelty, corruption and a world without mercy but you are not promising the reader fear itself, you are adjacent to grimdark rather than horror, and it is worth knowing which promise your tag makes.

However you build it, the genre has one commandment, and every source above keeps it: it must scare.