Knowledge (Int; Trained Only)
Like the Craft and Profession skills, Knowledge actually encompasses a number of unrelated skills. Knowledge represents a study of some body of lore, possibly an academic or even scientific discipline.
Below are listed typical fields of study.
•Arcana (ancient mysteries, magic traditions, arcane symbols, cryptic phrases, constructs, dragons, magical beasts)
•Architecture and engineering (buildings, aqueducts, bridges, fortifications)
•Dungeoneering (aberrations, caverns, oozes, spelunking)
•Geography (lands, terrain, climate, people)
•History (royalty, wars, colonies, migrations, founding of cities)
•Local (legends, personalities, inhabitants, laws, customs, traditions, humanoids)
•Nature (animals, fey, giants, monstrous humanoids, plants, seasons and cycles, weather, vermin)
•Nobility and royalty (lineages, heraldry, family trees, mottoes, personalities)
•Religion (gods and goddesses, mythic history, ecclesiastic tradition, holy symbols, undead)
•The planes (the Inner Planes, the Outer Planes, the Astral Plane, the Ethereal Plane, outsiders, elementals, magic related to the planes)
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).
In many cases, you can use this skill to identify monsters and their special powers or vulnerabilities. In general, the DC of such a check equals 10 + the monster’s HD. A successful check allows you to remember a bit of useful information about that monster.
For every 5 points by which your check result exceeds the DC, you recall another piece of useful information.