Talk:Underfoot Ring (5e Equipment)
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I grow tired of my edits being undone when the undo-er doesn't even provide an edit summary as to why.
As I said in my edit summary, magic items which permanently provide an AC bonus almost always require attunement. This is part of the bounded accuracy concept of 5e. According to that concept, a character should not be able to stack numerous AC bonuses; attunement prevents a character from ever stacking more than three from magic items providing such bonuses.
Aside from that though, this seems very powerful—too powerful for an uncommon item—in the right hands. For a Small character, this nearly as good as a +3 set of magic armor—which is a legendary item that requires attunement. In the Monster Manual, let alone lists of homebrew monsters, you'll realize after the first couple levels almost every significant threat is at least of Medium size. Consequently, a Small character would be getting this legendary-tier +3 bonus more often than not, and would only receive its relatively tiny penalty when targeted by the attack of a Tiny creature.