The way the rules are spread across the book for this confuses me. Here are the methods I consider with corresponding DCs when applicable:
- Read Magic spell (automatic)
- Spellcraft check DC 20 + Spell Level
- Identification spell and Spellcraft check DC 15 + Caster Level
- Identification spell and Spellcraft check DC 20 + Spell Level
- Analyze Dweomer (automatic apart from potential Will save)
At the moment, Read Magic is the one I don't doubt. Beyond that, I think these are the actual possibilities:
- Read Magic spell (automatic)
- Spellcraft DC 20+SL
- Identification spell and Spellcraft check DC 15 + Caster Level (just like any magic item)
- Analyze Dweomer (automatic apart from potential Will save)
I do not think the Spellcraft-only method is incompatible with the more general magic item identification method making use of ID spells and a Spellcraft check with a different DC. I also do not believe the Spellcraft method always requires the use of an ID spell.
But I may be wrong...
I'm curious to know whether there's a definitive answer from the RAW, and if so, what it is, or if it has to be left to subjective appreciation.
Note that I am focusing solely on identification: knowing what kind of magic is on the scroll, what it can do and, possibly, how to activate it. Since all scrolls activate the same way (Spell Completion), it's more about identifying the spells themselves. Based on the rules, I strongly believe identifying is different from using.
Here is my research so far:
When detect magic identifies a magic item's school of magic, this information refers to the school of the spell placed within the potion, scroll, or wand, or the prerequisite given for the item. (...)
Scrolls are definitely considered Magic Items and Detect Magic can identify their school of magic through their aura. It can be assumed the "identifying properties" part of Detect Magic is also possible.
Decipher the Writing: The writing on a scroll must be deciphered before a character can use it or know exactly what spell it contains. This requires a read magic spell or a successful Spellcraft check (DC 20 + spell level). (...)
This seems to say that to use or even know the content of a scroll, you need either the Read Magic spell or the given Spellcraft check with its specific DC. This is the one bit that implies scroll identification may be treated differently from all other magic items. Can one not "know exactly what spell it contains" and yet know its properties and function?
It does not say anything here about the Spellcraft check being linked to any other action such as casting Detect Magic first. This doesn't seem to be about reading an aura so much as... well, decyphering writings.
When using detect magic or identify to learn the properties of magic items, you can only attempt to ascertain the properties of an individual item once per day. Additional attempts reveal the same results.
The skill refers to these two identification spells and indicates one limitation.
Identify the properties of a magic item using detect magic: DC 15 + item's caster level
Decipher a scroll: DC 20 + spell level
There are two entries that may fit scroll identification. Both have different DC formulas. Note that the "decipher" one shows the same formula as indicated in "Decipher the Writing" and does use the word "decipher". This makes me think it is just a reference to that other section of the rules.
The only other mention of scrolls in the skill entry is for learning spells from one, so I do not think it's relevant here.
3rd Round: (...) If the items or creatures bearing the auras are in line of sight, you can make Knowledge (arcana) skill checks to determine the school of magic involved in each. (...) If the aura eminates from a magic item, you can attempt to identify its properties (see Spellcraft).
The spell refers to the skill entry for identifying properties on top of determining the school of magic. Scrolls being magic items, this should also apply to them.
Per RAW, everything seems to point at scrolls being identifiable through Detect Magic except the "Decipher the Writing" part which seems to denote an exception. I can't help but think it's a shame though, especially since I don't see any unbalance coming from using Detect Magic:
- It requires a spell
- It requires 3 rounds (for when that matters)
- You can only attempt it once per day per item (though it could be argued that the Spellcraft-only method should work the same)
- It does not allow you to read the scroll or use it
- The DC may be lower, but since it uses Caster Level it rises faster... and all the other limitations seem to compensate
Still, I may be missing some obvious abuse or other tidbits.