Caustic Smoke(Complete Mage, p. 98)
Conjuration (Creation) [Acid]
Level: Sorcerer 3, Wizard 3,
Components: V, S,
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Effect: Acidic fog spreads in a 20-ft. radius, 20 ft. high
Duration: 5 rounds
Saving Throw: Fortitude partial
Spell Resistance: No
Green-tinged smoke billows from the earth, obscuring sight and burning all it touches.
You create a bank of smoke, similar in effect to a fog cloud. In addition to obscuring sight, the cloud deals 1d6 points of acid damage per round to all creatures within. Furthermore, its acrid fumes burn the eyes, imposing a -5 penalty on all attack rolls and Search and Spot checks unless a creature succeeds on a Fortitude save (repeated each round the creature is within the cloud). These penalties last as long as the subject remains within the cloud, plus an additional 2 rounds thereafter.
If a creature within the cloud takes acid damage from any other effect, it must succeed on a Fortitude save (using this spell's save DC) or be blinded for 1 round.