30 Days of Night is a 2007 movie, directed by David Slade and starring Josh Hartnet and Melissa George. (IMDB Page)
Strange Day Cycle
I always found the idea of the changes in the day/night cycle fascinating for some reason, especially when they differ from the norm.
This is just something that can be used in an RPG as well, perhaps it’s set on a planet that has a 48, rather than a 24 cycle? How will that affect how things are done?
Another idea, for a more fantasy bent, is an area that is plunged into darkness until the heroes can rescue the sun from the underworld. This could work nicely for a more mythical quest.
The first hint that the main characters get that there is something going on in the town, is when they find a bunch of burned cellphones in the snow. This is never explained, although it might have been to reduce their chances of calling for help. Things escalate after that quickly, and the next step is the death of the dogs.
I like the fact that everything starts of with something small, the significance of which is not revealed until later.
Lets apply this to a haunted house story. Start of with the characters going into the house, perhaps a vacation home. The first thing they might notice is that
Blocking off the Exists
Things in the town continue to escalate after the cellphones are discovered, with the killing of the dogs, and later with the destruction of the helicopter. The impression is that somebody is preparing the town for an attack, and does not want anybody escaping.
This is something you can expand on, as the characters options for exists are gradually cut off, without the characters realising why. In a game it is a good idea to remember that the characters enemies can be organised and plan ahead. If the bad guys are planning to attack the characters, they might think of cutting phone lines first, or perhaps they create false alarms on the characters security system, so that they take it down for repair.
To be honest, I do not remember what the character was actually called in the movie, but he was definitely based on Renfield from Dracula. The somewhat insane servant to the vampires is a stock character, but can be used anywhere. Perhaps a lich has convinced a villager he would grant him immortality, if only he would get the PCs into a trap?
Becoming a Vampire to fight Vampires
Another classic trope, becoming the monster in order to have the strength to fight monsters. This is something that is very difficult to get right in an RPG. Either the players would do anything to get out of it, or would just go “Hey, I get to be super-strong, fast and regenerate! Where do I sign up?” The tricky part is making it a difficult choice, making it clear that without the added power the characters and their loved ones are doomed, but that the character who chooses to become the monster would be utterly damned in some way. Perhaps they could witness the degeneration of an NPC, who gets bitten by a werewolf, saves his family using his new found strength, only to wake up covered in their blood a couple of days later?