I've been browsing the NPC codex and the NPCs in there have a -2 to their CR, while the vampire aristocrate in Bestiary 1 has a -1 to her CR.
I am sure I missed something, but now I am confuzzled.
Vampires have a +2 CR adjustment from their templates.
And I'm fairly certain that it's not a flat -1 or -2 to CR, it's a combination of a number of factors, how many levels exactly they have and the like.
While it is true that the CR of an NPC class is their level -2, it gets complicated when you add levels to a monster with racial hit dice. It is something like +1 CR for each level that is complimentary to a monster's powers and +1/2 CR for each level that isn't.
See Monster Advancement/Adding Class Levels/Step 3. However, NPC classes are not represented on the Monsters With Class Levels table. In that case maybe you just consider the NPC class as the class it most closely emulates.
I am unable to find the vampire aristocrat in the Bestiary.
However as an example, I would expect a vampire aristocrat 5 to have a CR of 5. the NPC CR adjustment and the vampire adjustment would cancel each other out.
That's how I would do it (5 -2 +2 = CR 5).
PC class levels can do the +1 or +1/2 CR bit (depending on whether or not the PC class is 'key' for the monster). NPC class levels as I recall add +1/2 no matter what IIRC.
Is the vampire in question some kind of fey creature or monstrous humanoid?
Yeah, no vampire aristocrat in the bestiary. I confused the -1 PC classes give to CR for a NPC class.
Thanks.