Knowledge (arcana)

Knowledge (arcana) covers the theory behind magic, whereas Spellcraft covers its application. It encompasses two main fields of study – magic (arcane symbology and material components), and creatures (dragons and magical beasts).

Identifying a spell based on its effects falls under the Spellcraft skill.


The PC knows a good deal about magic in general, or can choose arcane or divine magic. Choosing one type or the other simply grants an additional +2 bonus when dealing with that type; the specialization bonus still applies.

Arcane Symbology: A PC can identify summoning circles, runes, written spells, etc.

A simple DC 5 check will identify a summoning circle; the DC is increased based on the circle's complexity and if the PC attempts to discern what exactly the summoner intends to call with it. For example, a circle made with powdered iron could be identified as one used to summon either an air elemental or a demon with a DC 12 check.

The PC can identify runes (those used to denote magical objects/powers, but that have no power of their own) with a DC 10 check. If the runes are part of a magic system, the DC is 20 to recognize them as magical, but a Spellcraft check is required to determine what they do.

If the PC came across part of a scroll bearing a fireball spell, he could make a check to realize that it was a spell of some sort, but he would need the Spellcraft skill to identify it. He could also recognize a complete scroll or spellbook in another language, or a nonstandard spellbook - tattoos, strings of knots or beads, or a carved staff - as a scroll or spellbook, though he wouldn't be able to tell what spell(s) were in/on it unless he could read the language or had knowledge of the magic system that uses them. A good rule of thumb here is that a DC 15 check can identify an item as a spellbook or item used to cast spells (a "scroll"). The DM can increase this to 20 if the item is especially arcane – the strings of beads, for example.

Material Components: The PC can attempt to identify a spell based on the material components, or name which components a spell requires. The DC for this is shown below.

DC 10 + spell level for common spells;

DC 15 + spell level for uncommon spells;

DC 20 + spell level for rare spells;

DC 25 + spell level for unique spells.

Common and uncommon spells often encompass outside sources related to the campaign world (ask the DM for more details). Rare spells are those that the DM deems so, or that are known to a handful of people (a mage and his apprentices, or a single organization). Unique spells are just that – spells created by, and known only to, a single person. The PC can't even attempt a check on such a spell unless he has seen it cast or written in some form, or has had it explained to him.


The PC knows a good deal about dragons and magical beasts.

Dragons: The PC can identify a creature of the Dragon type by sight with a DC 10 check (metallic and chromatic dragons need no check, unless they're extremely rare).

On a DC 13 check, he knows some useful information about a dragon of a given type, if it is common to the world (in a normal D&D world, this would cover metallic and chromatic dragons) – breath weapon, immunities, habitat, and general disposition. For every 5 points over the DC, he can recall another piece of useful information. The DC increases to 15 (or more) for specific dragons, depending on how well-known they are.

For example: Azarfellthinar the Flame, an old red dragon, has terrorized the northern kingdoms for decades, so a check to reveal information about him would be pretty low – DC 15. However, Azarfellthinar recently underwent the transformation to become a dracolich, so checks to determine his new abilities would be much higher – 25 to 30.

On a check of DC 13 + age category, the PC can make a rough guess at its age category (if the check succeeds by 10 or less, he still has a margin of error of plus or minus one category; if the check succeeds by 11 or more, he can tell exactly).

On a check of DC 15 + age category, the PC knows one or more abilities of a specific dragon – for example, that an 500-year-old (Old age category) green dragon is likely to be resistant to damage from nonmagical weapons (DR 10/magic), can create a wall of thorny growth (wall of thorns as a spell-like ability), and is resistant to magic. Each 10 points over the DC reveals another piece of information about the dragon.

Magical Beasts: The PC can identify most magical beasts on a check of DC 5 + ECL.

On a check of DC 10 + ECL, he knows a bit of useful information about the creature – habitat, intelligence, diet, abilities, etc.; for every 5 points over the DC, he can recall another piece of useful information.

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