Cloudkill

School: Evocation
Range: 10 yards
Components: V, S
Duration: 1 round/level
Casting Time: 5
Area of Effect: 40 x 20 x 20-foot cloud
Saving Throw: Special

This spell generates a billowing cloud of ghastly yellowish green vapors that is so toxic as to slay any creature with fewer than 4+1 Hit Dice, cause creatures with 4+1 to 6 Hit Dice to roll saving throws vs. poison with -4 penalties or be slain. Holding one's breath has no effect on the lethality of the spell. Those above 6th level (or 6 Hit Dice) must leave the cloud immediately or suffer 1d10 points of poison damage each round while in the area of effect.