For a long time, one of the DMs in my usual group has claimed that Knowledge (Local) has to be tied to a specific region. For example, you could take Knowledge (Restov). So, we've always just played under that assumption.
The rules, however, don't seem to make that obvious. In fact, they don't seem to suggest that idea at all.
From the PRD article on Knowledge:
Knowledge (Int; Trained Only)
You are educated in a field of study and can answer both simple and
complex questions. Like the Craft, Perform, and Profession skills,
Knowledge actually encompasses a number of different specialties.
Below are listed typical fields of study.(ed: skipping most of them)
- Local (legends, personalities, inhabitants, laws, customs, traditions, humanoids)
Check: Answering a question within your field of study has a DC of 10
(for really easy questions), 15 (for basic questions), or 20 to 30
(for really tough questions).
Then there's a DC table which includes the following entries for Knowledge (Local):
- Know local laws, rulers, and popular locations – DC 10
- Know a common rumor or local traiditon – DC 15
- Know hidden organizations, rulers, and locations – DC 20
It seems like Knowledge (Local) covers all (legends, personalities, inhabitants, laws, customs, traditions, humanoids), just as Knowledge (History) covers all (wars, colonies, migrations, founding of cities) and Knowledge (Nobility) covers all (lineages, heraldry, personalities, royalty).
So, is Knowledge (Local) tied to a specific region, or does it cover a broader scope like the other knowledges?
Best Answer
This confusion is an inheritance from D&D - particularly the Forgotten Realms. Region-based skills had particular rules in that campaign setting.
I believe it was most clearly explained in the 3.0 Forgotten Realms Campaign Setting (Pages 8-9):
The later (3.5) Player's Guide to Faerûn contained similar rulings.
Note that this was not true in general for D&D 3.0 or 3.5 (and neither have I encountered similar rules in the supplements defining other campaign settings). The general Knowledge rules were rather scant, the following being the entirety of the Knowledge skill description from the 3.0 SRD:
The 3.5 text is analogous to the later PF text. Further, monsters have been published that only reference a generic Knowledge (local) skill (example: The 3.0 Leshay), with no defined subcategory.
TL;DR version: Your DM is thinking of an old Forgotten Realms specific rule.