One of my players believes that Bardic Knowledge should be rolled anytime a Knowledge skill check called for. If the party party meets a Balor, he wishes to make a Bardic Knowledge check to see if he knows of the creature (as per Knowledge Planes). If he comes across some drow, he wishes to use the Bardic Knowledge check to see if he can know of them, etc.
I always saw Bardic Knowledge as being about specific people, places or things, not more generalized concepts. If he meets a random obscure drow, you can’t use Bardic Knowledge. If he meets Nathiria Lord Empress of the Drow Conclave, a Bardic Knowledge check would be in order (though I'd raise the DC, surface-race bard would have little access to stories and such of the drow.)
Anyway, when should Bardic Knowledge be used? When is appropriate, when is it not?
I always saw Bardic Knowledge as being about specific people, places or things, not more generalized concepts. If he meets a random obscure drow, you can’t use Bardic Knowledge. If he meets Nathiria Lord Empress of the Drow Conclave, a Bardic Knowledge check would be in order (though I'd raise the DC, surface-race bard would have little access to stories and such of the drow.)
Anyway, when should Bardic Knowledge be used? When is appropriate, when is it not?