[AD&D] Rules questions (my players stay out, I don't want you knowing too much)

[Kurald Galain]

A sword is mentioned as a sword +1, +3 vs. lycanthropes and shape changers that is "treated as a normal weapon against vampires". Does this mean a sword +1 against them, a masterwork sword (are those even in AD&D?), or as a mundane sword?

I would read this as a reminder that vampires aren't considered "lycanthropes and shape changers" (even though they can technically change shape, they're a different class of monster). So the +3 doesn't apply to them, but the +1 does. I believe that's a moot point since vampires require a +2 weapon to be hit, but there you go.

Regardless, it would still be a masterwork sword because all magical items are masterwork. If I recall correctly, masterwork weapons are +1 to hit, +0 to damage; or perhaps it was vice versa.