A magic-user with a magic staff or wand can choose to use it to absorb an incoming spell, ruining the wand or staff beyond repair.
What do you think? I imagine it as a last ditch attempt to survive a powerful foe. I didn't put anything about level because that probably would depend on how rare and dear a magic staff is in your campaign. If they are hard to come by, it would seem okay to sacrifice one even to a high level spell such as finger of death, and regardless of the level of the staff's owner.
Alternatively, you might let them absorb multiple spells with a chance each time that it will blow up catastrophically, say 25% chance for each spell, though I don't know that those would look like worthwhile odds to me as a player.