So just how effective are Mirado's Boots of Elvenkind?
S&W Complete is pretty definite on the subject:
"Boots of Elvenkind: The wearer of the boots moves with complete silence."
No word about speed restrictions, encumbrance, etc. As written, you could run in these puppies and not make a sound. It doesn't even say foot sounds, only - movement. So, breathing? Swinging swords? What's the cutoff, I wonder, for "movement." You could say they are boots, so it's obviously foot movement only, but a ring of invisibility doesn't just hide your finger or hand, and a cloak of protection works on your whole body. So it's a valid question in my mind.
AD&D was a lot more restrictive:
"Boots of Elvenkind: These soft boots enable the wearer to move without sound of footfall in virtually any surroundings. Thus the wearer can walk across a patch of dry leaves or aver a normally creaky wooden floor and make only a whisper of noise - say 95% chance of silence in the worst of conditions, 100% in the best."
That's what I was thinking of during the session, but the short version S&W went with makes it considerably better of a magic item.
Certainly they got a bit weaker in 3.x, according to the SRD:
"Boots of Elvenkind These soft boots enable the wearer to move quietly in virtually any surroundings, granting a +5 competence bonus on Move Silently checks."
But still, yeah, I need to ask our GM what effect he's thinking of.