Open Game Content vs. Product Identity
The single most important distinction in the OGL, and the one most likely to trip someone up: a license to use rules text is not a license to use everything else in the book.
Game mechanics and rules text — the numbers, formulas, and procedures. This is what the OGL actually licenses, and what you're free to build on and republish under its terms.
Trademarks and copyrighted non-rules content — characters, locations, organizations, deities, events, art, and maps. The OGL never grants any right to this, even when it appears in a book that also contains Open Game Content.
Paizo's own current licensing page states this directly: the OGL grants "the right to use only game rules content published under the OGL," and explicitly excludes "Product Identity, which includes Paizo's trademarks and copyrighted non-rules content, like characters, locations, organizations, deities, events, as well as art and maps." See Paizo Licenses (checked 2026-08-26).
A Section 15 citation is attribution, not permission — it tells the reader where mechanical content came from, but it never grants rights the underlying license doesn't grant. This site's own Product Identity/Open Game Content designations follow the same split: site logos, original setting names and lore, and unpublished drafts are all this site's own Product Identity, while only content expressly identified as Open Game Content is released under the OGL. See the full designation on the Guide Hub.
This is why a homebrew feat named after a published NPC still needs to treat that name as Product Identity, even though the feat's own mechanics might be entirely original Open Game Content.
Reviewed by Eco, 2026-08-26. Source: paizo.com/licenses, checked 2026-08-26.