This spell is an enhanced version of the level two Battle Magic spell Mystic Mist, creating a cloud 2D6 yards in diameter within the maximum range of the spell, but which is also poisonous and corrosive. Living creatures within the area of effect must make a successful poison test each round they remain within the Foetid Cloud or suffer an automatic S5 hit, regardless of armour. Trolls and other regenerating creatures may not regain damage suffered from a Foetid Cloud even when they leave the area of effect; it must be healed by rest or magic.