Almost anything a magic-user values can be destroyed by acid. The practioner of magic would therefore be wise to prepare for such exigencies. This spell, for instance, could be most efficacious:
Proof Against Acid
Spell Class: Magic-user
Spell Level: 3
Duration: 1 day per level of the caster upon exposure (also see below)
This spell provides total protection from normal acid for objects that would ordinarily be susceptible to damage from it. The amount of material that may be so protected is equal in mass to one heavy book per level of the caster. This spell also provides limited protection from magical acid, e.g. acid-based spells, acid-based breath weapons, etc. Any object protected by proof against acid is entitled to a +2 bonus to saving throws made versus the appropriate magical acid-based attack. Any such saving throw is made as if by a magic-user of the same level as the caster who originally cast the spell at the time the object received its protection. A successful save means no damage was sustained by the object. The spell remains dormant until it is activated by exposure to destructive acid. Once activated, the protection lasts for one day per level of the caster or until three saving throws have been rolled (whichever comes first).