In all the years that I have read horror stories, I have seen a lot of techniques that writers have employed. Most of them use a lot of word play, building up suspense as time passes and ending it with a spectacular display. (e.g. Jan Neruda's Vampire) Other times, I see that there is a seemingly unconquerable being or deity that attempts to kill characters as they try to fight it in vain. Majority I've seen focus on gore, blood and violence to bring about the scare. (Most zombie movies) There are a few that lets the atmosphere take over; they give off the impression that something is there, even though the probability of something isn't really there remains. (An American Horror Story, Another)
Which one really leaves more impact? Which one is more essential in a horror story? The atmosphere or the seemingly unbeatable ghosts, demons or other things? Or is it the gore which really brings the scare?