SRD:Detect Good

You can sense the presence of good. The amount of information revealed depends on how long you study a particular area or subject.

1st Round: Presence or absence of good.

2nd Round: Number of good auras (creatures, objects, or spells) in the area and the power of the most potent good aura present.

If you are of evil alignment, and the strongest good aura’s power is overwhelming (see below), and the HD or level of the aura’s source is at least twice your character level, you are stunned for 1 round and the spell ends.

3rd Round: The power and location of each aura. If an aura is outside your line of sight, then you discern its direction but not its exact location.

Aura Power: An good aura’s power depends on the type of good creature or object that you’re detecting and its HD, caster level, or (in the case of a cleric) class level; see the accompanying table. If an aura falls into more than one strength category, the spell indicates the stronger of the two.

Lingering Aura: A good aura lingers after its original source dissipates (in the case of a spell) or is destroyed (in the case of a creature or magic item). If detect good is cast and directed at such a location, the spell indicates an aura strength of dim (even weaker than a faint aura). How long the aura lingers at this dim level depends on its original power:

Animals, traps, poisons, and other potential perils are not good, and as such this spell does not detect them.

Each round, you can turn to detect good in a new area. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.