Lanefan
Victoria Rules
Bit of both. It's RAW that if you fail a save vs area damage your items and possessions then each have to save or be destroyed. It's a homebrew thing that on breaking, a magic item can sometimes release all its magic in a boom or a wild surge; and a boom can trigger another round of saves occasionally leading to a cascading series of destruction and pain. We call this a meltdown.Was that an AD&D rule or a home brew rule?
The 'boom' idea came from the 1e rules around intentionally breaking a wand (of lightning? fireball?) to generate a 'retributive strike': we tjhought that if it works this way for one item, why doesn't it work this way for all of them? At first the options were 'boom' or nothing; wild magic surges were added later.
It's been way too long but it sounds familiar and sparked a memory of dreading rolling saving throws for items.
Either way, I'm going to consider adding something like this to my home campaigns, for the same reason I added critical wounds - 5e is too safe.