Melf's acid arrow

Acid arrow, sometimes called more completely Melf's acid arrow is a somewhat complex wizard spell learned very early on in a mage's training. When cast, acid arrow conjures an arrow of acid that speeds from the caster's hand towards a single creature within 100 feet. The acid arrow, upon hitting, not only deals immediate damage but leaves a festering wound of acid.

Since the arrow is actually made of acid, rather than being coated with acid, it explodes upon contact with its target, spraying its contents onto adjacent creatures to injure them as well, to a lesser degree. It is also for this reason that, even if the arrow misses its initial target, it will still cause some small injury simply by its close proximity. Acid arrow, in spite of being a spell learned early on by most wizards, is of great complexity and requires so much concentration that mages can cast it only once per day.

Prior to the Spellplague acid arrow was a spell used by sorcerers as well as wizards, and was considered somewhat more complex. Like many other spells of the time, the potency of acid arrow grew over time with the caster's experience, particularly the duration of its effects. Acid arrow was also, like nearly all spells of the time, castable as many times per day as the wizard or sorcerer prepared for it - no more and no less. Some arcane spellcasters used powdered rhubarb leaf and an adder's stomach as ingredients for enhancing the spell.