Spellcraft

Spellcraft (Int; Trained Only) 

Use this skill to identify spells as they are cast or spells already in place.

Check
You can identify spells and magic effects. The DCs for Spellcraft checks relating to various tasks are summarized on the table below. See also: epic usages of Spellcraft.

Action
Varies, as noted above.

Try Again
See above.

Special
If you are a specialist wizard, you get a +2 bonus on Spellcraft checks when dealing with a spell or effect from your specialty school. You take a -5 penalty when dealing with a spell or effect from a prohibited school (and some tasks, such as learning a prohibited spell, are just impossible).

If you have the Magical Aptitude feat, you get a +2 bonus on Spellcraft checks.

Synergy
Additionally, certain spells allow you to gain information about magic, provided that you make a successful Spellcraft check as detailed in the spell description.
 * If you have 5 or more ranks in Knowledge (arcana), you get a +2 bonus on Spellcraft checks.
 * If you have 5 or more ranks in Use Magic Device, you get a +2 bonus on Spellcraft checks to decipher spells on scrolls.
 * If you have 5 or more ranks in Spellcraft, you get a +2 bonus on Use Magic Device checks related to scrolls.