Question: In a horror themed campaign with a Lovecraftian feeling, a big part of the game is a constant feeling of threat, but without any visual stimuli other than glimpses, or sounds vaguely heard of things seething in darkness, and with investigation a big part of the game, contrary to fighting.

Having read *Heroes of Horror*, I am searching for ideas on how to actually motivate players to assume the role of investigator rather than executioner, and how to instil the horror of the unknown, of something that threatens but is not substantial, that cannot be seen or heard, but is there, and has malevolent intent.

I am thinking of D&D 3.5 as a system, but I am interested in answers that cover any system (Call of Cthulhu is unfortunately out of the question), more as role-playing and storytelling techniques rather than mechanical ones.

Answer: 
The biggest ally in the bid to creep the players out is their own imagination. The biggest obstacle to that is your own. When running these types of campaigns, less is always more. It's just about finding out what 'less' should include.

1. Descriptions should hinge around one detail- the players' imaginations should do the rest. It's not about gore, nor about ultra-detailed descriptions, it's about triggering the players' mind to go overtime. Hint at the unknown rather than assaulting the player with it.
2. Engage all of the players' senses. In fact, engage other senses more than sight; reducing the applicability of sight to the description helps to engage the imagination, i.e the strange coppery smell, or the vision obscuring smoke that smells/tastes faintly of burning meat.
3. Building upon the details with small incremental revelations helps to lead the players' to where you want them to be. The realization that something is missing, or that something has been lost after an encounter with the unknown makes it that much more disturbing.
4. Repetition helps to inure the players to what you're doing- especially if that repetition is rhythmic or predictable. Even if not predictable, there is definitely a short shelf-life for when it will no longer be effective.
5. It is said that the best lies blend a kernel of the truth. It is also true that the best horror blends elements of the every day or of innocence. Take something that is safe and everyday/innocent and twist it for an effective factor of creepiness, i.e. the evil prophesy delivered in a child's singsong.

There are gimmicky techniques that can be blended with these to make them more effective, i.e. the soundtrack that comes on at an unexpected time, turning the lights down/off, sending notes to players in a way that others can see, but forbidding the player to talk about what's on the note... but these are just gimmicks and are not necessary to invoke that feeling of horror. Engaging the players' imagination is the key.
**Take their security blanket away**

A horror story usually starts with a build-up phase. As the PCs progressively discover their environment, give them small clues that won't lead to a fight, but hint at an ominous secret.

During this period, give the players reasons to feel safe. Maybe they have weapons. Maybe they escorted by a powerful authority figure. Or maybe the spaceship they're in has "failsafe" security measures.

Then, once the setting is established and the evil shows up, take the weapons away, have the players find the mentor's dismembered corpse after he said he'd "take care" of the crisis, and have the spaceship AI start counting down to a "critical meltdown".

**tl;dr:** give the players as many hints as you can that they're in danger and in over their heads, in a way that relies on minimalist narration instead of dice and numbers.