Determining Magic Used

[Shivian]

I know this likely gets asked a lot, but I can't find the mechanic (or at least, the simple mechanic) for determining how a spellcaster can utilize spells and / or skills to determine the actually spell that has been cast (or the effects of the spell that has been cast) on an object. I know I can have a spellcaster determine that an object has magic on it, but what if they want to understand precisely what the spell is (or at the very least, what it does) - how do they go about this?

[LeesusFreak]

That'd be a Spellcraft check, with a DC of 15 + the item's caster level.

[Duiker]

You roll either a spellcraft check or a knowledge (Arcana) check, depending on exactly what you're looking for. The PRD has a page for each that walks you through it:

Spellcraft

Knowledge