Detect magic

Detect magic is a universal spell that detects spells and magic items within sixty feet of the caster.

Effect
When cast, detect magic allows the caster to detect the magical auras around him. The amount of information revealed depends on how long the caster studies a particular area or subject.

This comes in three stages. First, the caster can feel the presence or absence of magical auras. Further concentration reveals the number of different magical auras and the strength of the strongest, slowly manifesting in the knowledge of the strength and location of each aura.

If the items or creatures bearing the aura are in line of sight, detect magic can sometimes determine the school of magic involved in each. If an aura falls into more than one category, detect magic indicates the stronger of the two.

The time an aura lingers depend on its original strength. Minor magical auras may last only a few minutes, while moderate ones may last up to an hour. Strong auras can last for several hours and the most powerful auras may resonate for up to several days.

Restrictions
While detect magic is powerful enough to penetrate barriers, certain materials can dull or even block it. A foot of stone, an inch of common metal, a thin sheet of lead, and three feet of wood or dirt block it entirely. Outsiders and elementals are not magical in themselves, but if they are conjured, the conjuration spell registers.

Magical areas, multiple types of magic, or strong local magical emanations may confuse or conceal weaker auras.