It is possible. And not that hard to handle (assuming the GM
carefully plans out scenes in advance).
Notice how I crossed out "carefully" above? That is because the way precognition works in DFrpg, it allows a character to assess (identify) or declare aspects in the world.
Assuming a GM has determined the 8 or so possible scenes in a scenario, most scenes should have their scene aspects (and possible character appearances) mapped out.
So the GM knows that the waterfront district has a scene aspect of "
Shadowed Alleys Swallow All Sound." All the GM has to do is pass such a note ("Shadowed Alleys Swallow All Sound") with maybe a brief description of some other sense's experience ("Smell: Salt Spray"). Or you can forgo the alternate sense experience and when the scene in question appears, allow an alertness roll to recognize a sense of déjà vu.
Acts of the player making world declarations can be used to help decide future scenes or scenarios. And there is no need for the GM to allow player originating world aspects to apply to
this scene (in fact, I would never allow such a level of precognition to apply to the current scene) or even the next scene.
But you could also pass aspects related to characters, like an aspect related to someone's temper ("
Tinderbox Temper") that could be tagged to avoid an ambush (as the temper NPC goes from social to physical conflict) or for an initiative bonus (for at least the first exchange). Or it could be tagged to compel (although I guess this gives the NPC a fate point) the NPC to break the peace first.
Don't forget however that the visions (aspects) granted by precognition don't HAVE to be used. Clues gleamed could be slightly irrelevant ("red herrings") to the scenario objective. Maybe the local mafioso has nothing to do with the disappearance of a missing person (but knows the missing guy has a Red Court Venom Addiction), but when you give players any detail (even if you tell them it is worthless) they will follow it to a dead end, then break their skulls pounding their heads against that dead end. So if you decide to lead your precog on a false trail, try to be kind and allow some sort of clue to come from it.
For example, in Storm Front
Dresden goes to the Velvet Room to try to get info from Bianca. But Bianca believes he is there to kill her, and even though she gives him a possible lead, he still makes a serious enemy and nearly had his throat torn out.
To handle these red herring visions, you could just make a list of scene aspects related to general activities of all Face characters in your city. A Malvora (or other fear WCV) might have the obvious fear feeding scenes, but could also be a bank manager that collects fear by scaring people with home foreclosures (****ing banks
).
If you do Cassandra's Tears without the disbelief, I would probably value it at [-1]. Maybe more depending on the character. A minor talent, [-1] seems really fair. If a player wants to over use it, keep a list of false aspects that will never come up (or again, reveal a slight variation of something the character already knows or something they just want, another red herring). In Small Favor,
Dresden has a precognitive experience, and later askes Anastasia about it. She tells him that all Wizards eventually start to have these visions, and the only reason they don't tell apprentices about it is to avoid having to listen to false prophecy after false prophecy.
An example of a false prophecy could be a character assuming he is really slick and "predicting" that this pretty woman behind the desk can be sweet talked into allowing them to visit with her boss without a prior appointment, so he thinks he has a "
I'm Just Her Type" aspect to tag, but really she could have the "
Not Another Sleazebag. SECURITY!" aspect.
As to how it works. It is clearly an Assessment or a Declaration (YS 324). There is no reason to use any sort of spellcasting system. I would say it is Alertness or Lore based. Alertness because that is the skill associated with passive perception, but Lore because Lore represents "Mystic Perception."
