Proposed nerfs for ring and wand destruction due to electric damage (some of them extensible to scrolls, spellbooks and potions for fire and cold damage):

• Rings never explode, as they are rarer and a more crucial part of a player’s gear. Only wands explode.
• Wands and rings made of metal never explode.
• The amount of wands and rings that can be destroyed by a single shock attack has a fixed cap. (Currently it has no cap and everything can be destroyed if you’re unlucky.)
• Extrinsic shock resistance (and only extrinsic) protects against these effects completely.
• Wands and rings hit by electricity act similarly to being charged, though they don’t actually get charged. Wands have their recharge counter incremented then roll for explosion. Chargeable rings roll for explosion at their current enchantment (meaning +0 rings will be safe). Not specified what should happen to unchargeable rings; perhaps they should just behave like +2 rings or something.
• The maximum number of items that will be destroyed is the amount of damage divided by 10, so an attack dealing less than 10 damage will never destroy anything, and e.g. a 6d6 damage attack from a wand will destroy at most 3 things. Combined with a possible hard cap of 5 or so items per damage.