Just a moment ago, it occurred to me that I could distinguish horror and stealth games only by their themes, atmospheres, aesthetics and tones. I can see no real mechanical differences between horror and stealth games, however. Both horror and stealth games involve hiding, avoiding enemies, rather than fighting them head-on, and both make the player-character weak, frail, and easily killed by enemies. They also both emphasize sound more than most other games, particularly environmental noises and the sounds enemies make. The biggest difference I can think of is stealth games require you to hide corpses. This seems like a trivial difference.
Of course, horror games scare us, while stealth games excite feelings of suspense. I’d consider these feelings two sides of the same coin. In mechanical terms, both feelings arise from the player-character’s vulnerability and the enemies’ strength. Horror games present this feeling differently, through scenes of gore, jump-scares, and moments that build psychological tension, but they do that through their atmosphere and storytelling, rather than their game-play mechanics. Not all horror games are sneaky, and not all stealth games are scary, but it seems to me no coincidence that, since the very early days of the original Clock Tower, horror games have involved stealth mechanics.
I think Thief 1 best shows us how easily a game can shift between stealth and horror. People always claim that Thief 2 is the superior game, and they’re half right. Thief 2 is a superior stealth game. But Thief 1 stands out to me for exactly the elements which Thief 2 eliminated: the horrific, supernatural exploration missions, such as the Lost City, and Down in the Bonehoard. To me, these levels work alongside the urban burglary missions because the same mechanics can work for both stealth and horror. Thief 1 deserves credit for using its mechanics to achieve a broader narrative scope, to frighten us and make us feel like sleek super-spies.
What do you all think? Can anyone identify some significant game-play mechanics that distinguish horror and stealth games? Try to refrain from using hybrid games as examples, e.g. Deus Ex or Resident Evil 4 or Dead Space. I’m talking more about games that most people would classify under one genre, e.g. Splinter Cell or Resident Evil 1, or games that combine only stealth and horror, e.g. Clock Tower, or Amnesia.