Arelith

When people take stuff from a chest or weapon rack, etc, a floaty message announces it to the surrounding party as either "Hin McStealypants takes a Ring (Unidentified) from the chest" on a success, or in a failure it would say, "Hin McStealpants takes something from the chest."

Another example of success could be: "Hin McStealypants takes a Blade Orb from the chest"

I'd think the check could be spot versus pickpocket (sleight of hand).