Okay, so fairly simple question that's been scratching my head and I was looking for a good answer.
A small PC decides to reduce person himself, and his already bad STR gets worse as he drops a size. Now, he should be okay but here's the kicker, at his current STR his light load is 13 lbs at his current size, the DM however rules that the bag of holdings weight stays the same regardless of Size and he can't carry one when tiny without it being a medium load. His reason is that, Bag of Holding is one of the few items who's internal dimensions and external weight are fixed, and the item is way too good for a smaller character then, so the item's weight stays locked.
I disagreed, saying that all items in their possession shrink also, thus the items(and there for the dimensional space) weigh less till the spell is removed and/or the items leave their possession. Especially since the weight of weapons, armor, everything should be increment out from medium size anyways, so the bag(and it's contents) should be 1/4 their usual weight. At 15 lbs(a type 1 anyways), it should be like 3.75 lbs when tiny imo since the item is scaled for medium creatures. I also cited the magical items resizing rule, as the intent imo is that a small gnome should be able to use a Giant's Handy Haversack just as well as the Giant does, but not more efficiently nor less so.
Thoughts? Also apologizes if this was already covered, didn't see anything after a quick search.
Even with the resizing rules, the Item itself lists a specific weight weather empty or full. I think the DM's rule is fine since it could go either way. technically the contents would NOT be effected being in a different dimension, and could, technically, have trouble being removed if you consider the now smaller entrance size of the bag itself.
The weight of the items inside the bag is irrelevant to the weight of the bag, so it doesn't matter (for this purpose) whether they shrink or not. The extradimensional space attached to the bag is not an "item" in any sense, and its weight is fixed, so... I side with the GM.
I think it's fair to not have the items resized in the bag, if given Rathendar's point that they can't get out with the new item.
It's just really weird to me that reduce person would actually make you unable to carry an item that you normally would be able to carry and would shrink with you. A corner case for sure, but still very weird.