If a hunter hits on investigate and supplies the right fictional explanation, I'm obliged to give them an answer, even if I didn't consider that the vampire left some bloody rags at the scene of its last attack.
This is super-important, and something that is easy to miss. As the Keeper, your job is not to consider the scene of the investigation before the PCs get there and predetermine the available clues; rather, your job is to honestly respond to the questions that their successes allow them to ask. So if the PC asks, "What sort of monster is it?"
, your job is to come up with some kind of "evidence" that reveals this information. You might have originally envisioned an attack that left no witnesses, but if the players ask something that only a witness would likely have known, congratulations, you've just invented a witness! Now tell the players who they are, how they saw what they saw, and how it is that the monster left them still alive:
"While you're investigating the murder scene, a neighbor gets stopped by the uniformed officers out front. At first you write him off as a rubber-necker trying to get a look at the carnage, but he keeps asking if 'the pretty lady in 3B' is OK. At first he doesn't want to answer any questions about who he is or what his connection to the victim is, but when you ask for his ID, you realize that he lives across the street and that his balcony overlooks hers. After you threaten to haul him off to jail for voyeurism, he agrees to cooperate. But whatever he saw has him pretty shaken up. His story is a little disjointed, but he eventually reveals that..."
It's the same with read a bad situation
- you come up with the answers to their questions in the moment, adding to the fictional landscape as necessary to answer their questions and propel the story. Once you get the hang of it, this is an incredibly useful and powerful GMing tool because it lets you alter the direction of the story based on what the players are doing
(as opposed to plotting/planning everything out beforehand). So if they ask, "what's my best way in?"
, invent a way in. If you already did a little prep and you have something in mind, great. But if not, make something up right now. "Well, there's an old storm-drain that runs under the property. Gods only know what's down there or where it comes out, but that certainly would get you inside the perimeter." This is you presenting an opportunity, with or without a cost
, which is one of your basic Keeper moves.
Does this make sense?