You can sense the presence of chosen alignment. The amount of information revealed depends on how long you study a particular area or subject. The alignment to detect is chosen when preparing the spell.
1st Round: Presence or absence of alignment.
2nd Round: Number of auras of chosen alignment (creatures, objects, or spells) in the area and the power of the most potent aura present. If the strongest aura's power is overwhelming and opposite of your alignment (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 aura's power depends on the type of 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.
For example, as indicated on the table, an evil outsider with 12 HD has an overwhelming aura of evil. A good cleric who casts this spell and directs it at the location of such a creature for longer than 1 round loses the spell and is stunned for 1 round if his character level is 6th or lower.
Aura Power
Creature/Object
Faint
Moderate
Strong
Overwhelming
Creature1 (HD)
10 or lower
11 - 25
26 - 50
51 or higher
Undead (HD)
2 or lower
3 - 8
9 - 20
21 or higher
Outsider (HD)
1 or lower
2 - 4
5 - 10
11 or higher
Cleric2 (Class Level)
1
2 - 4
5 - 10
11 or higher
Items or Spell (Caster Level)
2nd or lower
3rd - 8th
9th - 20th
21st or higher
1. Except Undeads and Outsiders, which have their own entries
2. Some characters who are not clerics may radiate an aura of equivalent power. The class description will indicate whether this applies.
Lingering Aura: An 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 alignment 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 evil or simply does not have alignment, and as such this spell does not detect them.
Original Strength
Duration of Lingering Aura
Faint
1d6 rounds
Moderate
1d6 minutes
Strong
1d6 x 10 minutes
Overwhelming
1d6 Days
Each round, you can turn to detect alignment 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.
