Ugly, but not Frighteningby
Horror games, for the most part, simply aren't frightening. Gory, disgusting, silly, or ugly, but not frightening. There are a number of games available that could be considered horror games, Call of Cthulhu, AD&D Ravenloft and Vampire, spring foremost to mind. And while Dark Conspiracy and Conspiracy X don't call themselves horror games, the settings have obvious horror elements. However, the way these games are generally played they are no more frightening than your average game of Paranoia.
AD&D Ravenloft was designed to be a horror setting for AD&D characters. What it became, however, is simply another monster-bash in a more gothic setting. The largest problem with playing a horror game in AD&D is the fact that most AD&D players have memorized the Monster Manual and know the weaknesses of a banshee. Subsequently, a session within Ravenloft ends up sounding like this:
Call of Cthulhu, is completely the opposite. You meet a strange other-world beast you go insane, die, or both. And because the players know they're going to run into hideously deformed creatures, go insane or die (or both) much of the atmosphere of the game is ruined. Not to mention the fact that H.P.Lovecraft's stories themselves weren't really that frightening - weird, goofy, and maybe a little gory, but not truly horrific. That being the case, is it any wonder why I think that CoC is really best suited for one-shot convention games?
Vampire, Werewolf and Wraith. With titles like that one would think that they were horror games, and White Wolf's own web page even declares them to be so. So why are there no horror elements? When a character is the monster then they really don't have much to fear, do they? It might be a pain to be discovered as a Vamp, or whatnot, but you can always just lie in hiding for a couple decades or so. Vampire, despite the claims of being a horror game really is more of a political, bite your way to the top, game.
The largest problem I have with horror-game systems is the fright-check (or insanity table). It deters from role-play. Let the players decide how their characters react. If the characters react afraid then it's a good game, if they charge the horror then either the GM, the players, or both might consider going back to the dungeons to bash goblins.
Of course, it's not really the game system's fault that the game is not scary. The large problem with running a horror game lies in two parts: the players and the GM. It would take a lot to even send a shiver up the spine of an experienced player, and throwing Shugreth the Unenviable in their face isn't going to do it... not unless the GM gets the timing right. The problem is, most GMs don't have the patience for proper horror timing, nor do most players.
A true horror game requires three things, atmosphere, plot, and timing. With most games it's easy to immerse oneself into the game regardless of surroundings, not so with horror, however. Dim candle-light, low-volume music (Mass works very well, as does Gregorian Chants) will help keep players in the right frame of mind. Dim lights are the important thing, when a player has his senses dulled, it's easy for him to envision his character in a dark place, as well. It's also important for the GM to have his plot laid out in advance. Horror games require the GM to know what their players will be up against, the history of the horror, and where and when it appears, otherwise the timing will be off.
Which leads to the third, and most important aspect of running a good horror game, timing. Timing is what separates a good horror movie from a simple monster flick. Timing is the art of knowing what to spring on a player and when. This doesn't mean constantly letting the players run into a monster. Some of the best horror movies don't let the characters know what they're up against until the final show-down. Keeping the characters (and players) guessing, and simply showing them after-effects or letting them think they're near the horror keeps the players on their toes and that makes them easier to scare.
Horror games don't necessarily mean monster, either. The effect of fear is what horror games are about, this can be done through serial killers, awakening psionic powers, or even a bitter old man wearing a costume (make sure you have a great Dane with you though).
I realize I'm actually covering two different horror topics here, but I thought that if I wrote more than one, I'd be infringing on Peter Devlin's Bell Book and Candle column. Which, by the way, is what helped me decide to run a horror game for my group.
Horror games are quite possibly the most challenging games for a GM to run, however, if the players like it they'll come scrambling in for a sequel. It's kind of like horror movies that way - look at all the sequels for movies like Nightmare on Elm Street, Halloween, Friday the = 13th, and Police Academy!
-Roll saving throw versus bad-gaming