Most survival horror games are a mix of two things, resource management and atmosphere. Atmosphere is what really separates a horror game from a normal shooter. It defines the genre.

Lots of genres focus on resource management: tower defense, real-time strategy, even many RPGs. However, none of them bring the intensity that goes along with kicking down a door in a haunted mansion with three bullets left, not knowing what is on the other side.

Atmosphere has always been a major part of horror games, but some of them create a scarier ambiance than others. Silent Hill was one of the first to try something new by adding mist. It was added to cover for the technical limitations of the original PlayStation. Even though it was originally conceived as a way to cover draw distance, it made the game much scarier than it would have been otherwise.

Other games have tried all sorts of things to push the fear factor through the roof. Dead Space used amazing sound design, F.E.A.R. messed with visuals, and BioShock gave us a faceless villain and fallen paradise. There are a myriad of ways to terrify and entice players simultaneously. Every dark, bloodstained hallway could be holding monstrosities or nothing at all. That tension is what makes the difference. Without the right atmosphere, an empty hallway is just an empty hallway.

The most exciting thing happening in game design right now that can enhance atmosphere is procedural generation. Some games, like Zombie Studios’ Daylight, have created systems which randomly generate rooms and object locations. This allows them to keep the player literally and figuratively in the dark. While the game wasn’t received particularly well, it did prove that randomization in horror games works. People fear the unknown and keeping most of the game unknowable will always make them scarier.

Hopefully you’ve enjoyed this look at how survival horror games are made. We would love to hear what environments and levels creeped you out the most in the comments below.

Mike Bertrand is MONG’s foremost expert on survival horror games and will be happily dropping knowledge bombs on your faces all month. Tweets.