I've found that the majority of players play along with my character's disguise, although he uses it incredibly sparingly and I change my description fully for it. I also make it quite clear that he is deliberately hiding his face. Still - Here's my thoughts on the matter:
It's one thing if you change your description, change everything about your appearance, aren't wearing your Sanctuary ring, and you simply walk through "hostile" territory. I'd imagine most players, on seeing a black-clad thug with a helmet on walk through Lower, won't be like OMG that's obviously XYZ from Upper let's kill him/her. On the other hand, I don't think if an established Upper character decided to go around questing with Lowerspeople in a disguise...they'd adventure and fight with him/her without noticing their identity. It depends on the extent of roleplay.
I don't think skills play into it that well. I don't care how good your spot is, if you've never met the character before you can't discern who it is, if they're wearing a helmet you can't see their face. Even if you said "my spot is so good I can tell from your muscular build", I'd disagree. Also, it doesn't take bluffing skills to be able to dress differently and put on a helmet.
It's one thing if you change your description, change everything about your appearance, aren't wearing your Sanctuary ring, and you simply walk through "hostile" territory. I'd imagine most players, on seeing a black-clad thug with a helmet on walk through Lower, won't be like OMG that's obviously XYZ from Upper let's kill him/her. On the other hand, I don't think if an established Upper character decided to go around questing with Lowerspeople in a disguise...they'd adventure and fight with him/her without noticing their identity. It depends on the extent of roleplay.
I don't think skills play into it that well. I don't care how good your spot is, if you've never met the character before you can't discern who it is, if they're wearing a helmet you can't see their face. Even if you said "my spot is so good I can tell from your muscular build", I'd disagree. Also, it doesn't take bluffing skills to be able to dress differently and put on a helmet.