Caustic Gas

School: conjuration [gas]
Circle: ancient 3rd, arcane 3rd, occult 3rd
Spell Components: V, S
Action Time: 1 action
Range: medium
Shape: radius (large)
Targeting: all (radius)
Base Duration: instant
Saving Throw: fortitude half
Spell Resistance: no
Ritual Components: any refined poison phial

Unleashes a corrosive field over the target area, dealing 1d6 acid damage/round, lingering for 1d3+1 rounds, +1 round/2 levels. Like all gases, it will be dispersed if any part is affected by gust of wind.