Acid Shower is a Battle Magic spell available from Geneforge 2 and onward. It requires a skill of 6 to be cast. This spell drenches all enemies around the caster in acid and deals damage on subsequent turns (does not do damage on initial cast). The spell is very intensive in Essence use.
The spell is identical to that of Acid Spray and Burning Spray except that it possess the area effect. Most players use this during a heavy boss fight as many bosses summon extra creations that can be tedious to take care of.
Rothizdrons (some varieties) are known to occasionally 'cast' this spell. The game refers to this as (spraying acid). Mines, traps, and vats also can use this spell repeatedly out of combat.