Knowledge skills are the cinderella of the skill set. Nobody really puts grades in Knowledge (local), Knowledge (Nature) or Knowledge (Royalty). If you have a bard in the group, all these knowledge are made useless by any bardic lore, otherwise you can always roleplay them out of NPC conversation. Grades in knowledge are wasted, and players know it.
This is the reason why, as far as I understand, grades in knowledge are prerequisite for prestige classes. Nobody would pick them otherwise.
The question stands. How can I increase, either as a player or a GM, the importance of grades in knowledge skills without appearing insanely pedantic ? Should I force the players to dedicate at least one grade per level in knowledge ? Is it a viable strategy ?
Best Answer
Knowledge (royalty) I'll give you. It's dumb and should get stuck into Kno(history) or (local) unless you are running an all courtly intrigue all the time game. But Knowledge (nature) is used for "monster ID" of animals, fey, giants, monstrous humanoids, plants, and vermin - it's one of the better ones! And Knowledge (local) has been invaluable in my games, especially city-based ones. (And it's used for humanoid ID.)
Knowledge skills should let you get an advantage if used right. If you are wandering around and find a cave with a scratched up tree outside it, Knowledge (nature) should tell you that's probably a bear's cave and since it's December it's probably hibernating. Of course this requires the PCs to not just happily run from random encounter to random encounter like they're grinding in WoW. Think "Man vs. Wild" or most of the other shows on those channels for this skill. There is overlap with Survival, but that skill is just tracking and eating and avoiding natural hazards and that's it. If it's plant or animal or whatnot it's Kno(nature).
Similarly, knowledge (local) tells you that guy in the bar flirting with the waitress is a local enforcer for a crime boss and he's killed guys a lot more skilled than you - so you probably don't want to mess with him. Or even that he has a weakness for dwarven stout, if you want to chat him up. Heck, this is the one skill most people in my game have, because they get sick of waking up in bathtubs full of ice in inn rooms with a note about how they need to get to the local temple since they're out of kidneys now.