What is Rule #1 of writing horror fiction?
Rule #1 is: Take your subject matter seriously--or don't write horror fiction.
One of the great flaws of modern popular culture is its excessive reliance on irony.
Now, don't get me wrong: Irony has its place: I love comedic movies like Blazing Saddles. I enjoy the satirical essays of PJ O'Rourke and Dave Barry. I even enjoy the occasional wisecracking vlogger on YouTube. I'm not saying that writers, filmmakers, and performers have to be 100% serious, 100% of the time.
Nothing wrong with irony!
But irony (or satire) as the basis of horror film or fiction is a recipe for failure. It's a bit like trying to make a milkshake with catsup, or trying to make a salad from raw liver.
Nevertheless, irony has become a prevalent trend in horror film, in particular.
Examples include: Zombieland (and its various imitators), Drag Me to Hell, and the Scream films.
These movies might be entertaining--after a fashion, but they aren't very scary. They never achieve the "suspension of disbelief" that is required for horror fiction (or film) to work.
Let's consider why that is the case: What, after all, is the horror writer's job?
The horror writer is supposed to create a profoundly moving (and usually allegorical) tale that deals with topics of life and death.
There are different kinds of horror fiction. Some horror fiction is naturalistic. Naturalistic horror deals with serial killers, natural disasters, and even wild animals (think Jaws).
Other kinds of horror fiction rely on supernatural villains: vampires, ghosts, demons, etc.
In either case, the horror story is fundamentally about a struggle with death--whether existential or spiritual.
This is a serious topic, whatever form it takes. And the most effective horror films and fiction don't have a laugh track. The Exorcist, The Shining, The Walking Dead, and The Conjuring are all respectably frightening. They cast a spell and they draw you in, persuade you to believe in hypothetical scenarios that you would ordinarily dismiss as "impossible".
Notice that none of these literary/cinematic works relies on a laugh track.
When a horror writer tells the reader, "I'm not really serious about any of this!" by attempting to make horror ironic or funny, what he is really saying is, "I don't want you to actually believe any of this--even for the duration of the short story/novel/film. I'm just pulling your leg here!"
This doesn't mean, incidentally, that a horror novel or film has no room for the literary device known as "comic relief". Shakespeare famously employed comic relief in his tragedies like Macbeth and Hamlet. That didn't make Macbeth or Hamlet less "serious".
The Shining (the novel) has some humorous family scenes, as does King's scariest novel, Pet Sematary. And Cujo has at least one scene that is roll-on-the-floor hilarious.
But none of these scenes involve the presentation of the ghosts, the evil spirits, and the monsters that inhabit King's works and provide the chills. When King is writing his "monster" scenes, he writes with a serious tone.
There is nothing inherently funny about a patch of ground that reanimates corpses (Pet Sematary), a hotel haunted by evil spirits (The Shining), or a rabid dog that kills people (Cujo). And so King doesn't try to make them funny. When King depicts the antagonist forces in his novels--be they human, animal, or supernatural--he imbues them with genuine threat.
This requires a straightforward tone of voice, free of the irony that many writers nowadays seem to find obligatory. This is why Stephen King's novel's are scary--or at least compelling to read.
The important takeaway here is that the writer must take the horror element itself seriously. If you can't take the horror element seriously, then you shouldn't be writing horror fiction. You should be writing something else instead.
Let's get back to The Walking Dead, which almost all readers will be at least somewhat familiar with.
Most of us would agree that the idea of the zombie apocalypse is well...pretty unlikely. This isn't a concern that keeps me up at night.
However, while you watch an episode of The Walking Dead, you temporarily and provisionally believe in the zombie apocalypse. Why? Because the writers and producers of The Walking Dead take the basic premise of the story--the horror element--seriously. And as a result, you take it seriously, too.
On the other hand, comedic horror films never achieve this suspension of disbelief, because of the fundamental incongruity in how they present the horror elements.
The writer of Zombieland obviously didn't take the idea of a zombie apocalypse seriously. Zombieland presents the whole concept as a load of bunk--a big joke--and so it never moves, enthralls, or captivates viewers like The Walking Dead does.
The Walking Dead is a classic. Zombieland is forgettable and disposable.
I repeat: Irony has its place. But irony should be used sparingly in horror fiction, and never for the presentation of the horror elements themselves.