These are some of the more popular subgenres of horror, but by no means is this list all inclusive.  Even among horror purists there is much debate about these categories, so these should be used as a general guideline.

Dark Fantasy – A fantasy story with “dark” themes, characters, etc. that isn’t usually the standard mainstream stories.

Erotic Horror/ Sexual Horror – A horror story that contains sexual content as an integral, but not necessarily enjoyable, part of the story. This can also include a softer, “romantic” tone as well.

Extreme/ Splatterpunk – A straight to the blood story. This genre goes to the extreme in terms of explicit violence and gore, and tries to go for the shock factor.

Gothic – Evil from the past in a historically romantic setting. Includes haunting, castles, insanity, etc. often written in a literary style.

Noir – Moral ambiguity, cynicism, corruption, alienation, and obsession, against a backdrop of pessimistic and dingy realism, in a gritty urban setting.

Paranormal – Mortal hero against encroaching supernatural forces. Although in my experience this blends in with several other subgenres especially supernatural.

Quiet Horror/ Soft Horror – This subgenre is the opposite of the extreme/splatterpunk. Mood and atmosphere supply the tension. It’s emotion rather than physical violence.

Supernatural – Features elements and characters outside of the normal world. This can also be considered paranormal.

Surreal – Unreal, strange, bizarre.

Suspense/ Thriller – No supernatural elements. In these stories there is a feeling of constant threat or menace.

Lovecraftian – From the author H.P. Lovecraft. These stories often deal with the Cthulhu mythos, ancient secrets, florid prose, and pessimism. Needless to say if you are going to write stories in this subgenre, you should definitely read the author’s works.

Religious/ Satanic/ Occult – These stories are centered around certain belief systems. They incorporate demonic possession, exorcisms, and pagan religions.

Parody/ Comedy – A horror story with comedic elements. Parodies often feature stereotypical horror situations and characters.

Slasher – This could be considered the extreme/splatterpunk category for the big screen. Usually features a deranged killer going after immoral victims.

Psychological – This subgenre deals with deranged and damaged minds. If it’s a psychopath on a rampage or a narrator slowly going insane with an increasingly confused reality, it can fit into this category. The stories that fall into this category usually leave the audience in suspense of what is real and what is imagination.