buying knowledge skills

[Uber Dungeon]

Does anyone know anything about buying new knowledge skills? I saw it mentioned but I never could find anything else about it, like how is such a thing done or is it nonsense?
I would guess that it would cost 2 skill points to get a new knowledge skill, or something along those lines.

 

[Patryn of Elvenshae]

Putting ranks in a new Knowledge skill follows the same rules for putting ranks into a skill you already have ranks in.

I'm not sure I understand the question.

 

[Greenfield]

Depends on the character class. Some classes have "Knowledge" as an "In class" skill, some don't.

Wizards, for example, pay 1 skill point per Knowledge skill. Fighters pay 2.

Now your DM may decide to put some in-game requirements, like finding a teacher or study source, but that's campaign specific and can only be answered by the DM.