Knowledge (int ; TRAINED ONLY )

 
Knowledge SkillDescription
Arcana Ancient mysteries, magic traditions, arcane symbols, cryptic phrases, constructs, dragons, magical beasts
Synergy: If you have 5 or more ranks in Knowledge (arcana), you get a +2 bonus on Spellcraft checks.
Architecture and engineering Buildings, aqueducts, bridges, fortifications
Synergy: If you have 5 or more ranks in Knowledge (architecture and engineering), you get a +2 bonus on Search checks made to find secret doors or hidden compartments.
Dungeoneering Aberrations, caverns, oozes, spelunking
Synergy: If you have 5 or more ranks in Knowledge (dungeoneering), you get a +2 bonus on Survival checks made while underground.
Geography Lands, terrain, climate, people
Synergy: If you have 5 or more ranks in Knowledge (geography), you get a +2 bonus on Survival checks made to keep from getting lost or to avoid natural hazards.
History Royalty, wars, colonies, migrations, founding of cities
Synergy: If you have 5 or more ranks in Knowledge (history), you get a +2 bonus on bardic knowledge checks.
Local Legends, personalities, inhabitants, laws, customs, traditions, humanoids
Synergy: If you have 5 or more ranks in Knowledge (local), you get a +2 bonus on Gather Information checks.
Nature Animals, fey, giants, monstrous humanoids, plants, seasons and cycles, weather, vermin
Synergy: If you have 5 or more ranks in Knowledge (nature), you get a +2 bonus on Survival checks made in aboveground natural environments (aquatic, desert, forest, hill, marsh, mountains, or plains).
Nobility and royalty Lineages, heraldry, family trees, mottoes, personalities
Synergy: If you have 5 or more ranks in Knowledge (nobility and royalty), you get a +2 bonus on Diplomacy checks.
Religion Gods and goddesses, mythic history, ecclesiastic tradition, holy symbols, undead
Synergy: If you have 5 or more ranks in Knowledge (religion), you get a +2 bonus on turning checks against undead.
The planes The Inner Planes, the Outer Planes, the Astral Plane, the Ethereal Plane, outsiders, elementals, magic related to the plane
Synergy: If you have 5 or more ranks in Knowledge (the planes), you get a +2 bonus on Survival checks made while on other planes.

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.

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.

Action: Usually none. In most cases, making a Knowledge check doesn’t take an action—you simply know the answer or you don’t.

Try Again: No. The check represents what you know, and thinking about a topic a second time doesn’t let you know something that you never learned in the first place.

Synergy: Synergy bonuses are listed in the above table.

Untrained: An untrained Knowledge check is simply an Intelligence check. Without actual training, you know only common knowledge (DC 10 or lower).