In our AD&D hey-day it wasn't a problem, all the DM's in my area pretty much knew each other and there was little or no concern or suspicion.
One of the better ways to deal with such a Player comes from "Booty and the Beasts", if you read my blog you will know I am working my way through that tome converting things over to C&C (I might even do a PDF of it when its all finished) and today I am 'blogging' the Malevolent Mana Muncher from BatB - and this little critter is a GREAT way of dealing with the too many Magic Items problem (even if you caused it yourself).
NO. ENCOUNTERED: 1–4
MOVE: 70 ft
ATTACKS: 1 (snatch item)
SPECIAL: Super fast (+5 to initiative), resistant to magical blasts & explosions
XP: 2100+16 per HP
These irritating little beasties are totally inoffensive to other creatures they might encounter – beyond their driving desire to steal and devour magical items as they feed off the magical energy that is stored within them.
Mana munchers are surprisingly fast, and their 3 extremely dextrous tentacles can snatch off any loosely held item (amulet, crown, brooch, etc.) on a roll of 6+ on a d20. Once it has an item, it then stuffs it into its frothing innards, any item a mana muncher attempts to digest in this manner must make a save vs. acid and being crushed – as the mana muncher chomps down on the item and attempts to digest it.
A mana muncher suffers no ill effects from exploding staves, wands, and the like – as it feeds off the magic such explosions produce.
If a mana muncher attempts to grasp a firmly held item – such as a staff, sword, or ring – and is successful in its roll, the target of the munchers attack must make a strength test or lose a hold of said item.
Mana munchers only snatch magical items, leaving all mundane gear alone.
These annoying creatures are encountered in groups of 1-4 individuals, and are generally found rummaging through old temples and ruins.