Hypersmurf said:And not necessarily true.
Magic armor certainly shouldn't resize to fit someone in an Antimagic Field... but then, while it's in the Field, it isn't magic armor, so that's kinda a given.
But you're assuming that the resizing is an effect with a duration, or a continuous effect, that can be suppressed. What if when someone goes to put it on, it transforms to the new size as an instantaneous effect? Now it's not fat dwarf armor masquerading as skinny elf armor... it's skinny elf armor that was, once upon a time, fat dwarf armor.
Since the effect was instantaneous, there's nothing to suppress when it hits an AMF...
-Hyp.
Edit - now, this interpretation could cause a problem if the armor is being worn by a magically transformed (Polymorphed, Enlarged, whatever) creature, since the armor would not change when it hits the AMF, but the wearer would...
Yes, I made that assumption since all size altering spells (TMK) have durations which are not instantaneous (Enlarge, Polymorphs, Righteous Might, Shapechange, Shrink Item, etc.) and most are transmutations (I cannot think of one which is not).
Personally, I like when the rules work the same, not when you have exceptions that are not called out in the rules. DMG page 9: "Look to any similar circumstance that is covered in a rulebook. Try to extrapolate from what you see presented there and apply it to the current circumstances."
But, if your armor (or ring or bracers or whatever) reverts back in size, you can have a problem even if you were not polymorphed (7 foot tall Barbarian with a Ring of Water Breathing suddenly has a pinky sized ring on his huge finger or his armor is suddenly dwarf sized again).
Both interpretations could have an issue.
This is similar to the golem issue. Constructs are magical and should be suppressed in a Antimagic Field, but WotC in its infinite wisdom decided against that. Not sure why. Did they change that in 3.5?