Know Alignment {Wizard}

A know alignment spell enables the wizard to read the aura of a creature or an aligned object (unaligned objects reveal nothing). The caster must remain stationary and concentrate on the subject for two full rounds. A creature is allowed a saving throw vs. spell and, if successful, the caster learns nothing about that particular creature from the casting. If a creature or object is concentrated on for only one round, only its alignment with respect to law and chaos can be learned. Certain magical devices negate the know alignment spell.

Reverse: Undetectable Alignment

The reverse, undetectable alignment, conceals the alignment of an object or creature for 24 hours — even from a know alignment spell.

[Player's Handbook]

Reversible

School: Divination
Level: 2
Rarity: Common

Range: 10 yards
Components: V, S
Duration: 1 round/level
Casting Time: 1 round
Area of Effect: 1 creature or object per 2 rounds
Saving Throw: Negates