I was also thinking a skill that would add a bit to the rogue class. I saw it elsewhere called Garrotte, they needed a thin black wire to use the skill which silences the victim.
I think it would be useful and help flesh out the class a bit.
Garrotte Skill Suggestion
I like the idea, but I think it would have to have some sort of restrictions in terms of placement...to get a wire around someone's neck would require some sort of attack of opportunity, which for the rogues would mostly be from hiding, but then encouraging attacks out of hiding might mean attacks with less pre-attack RP. Basically, I don't think a rogue facing off against someone would be able to get around them and get a wire around their neck unless the other was somehow incapacitated by, say, dirtkick, blindness, or some sort of stunning skill/spell. It's kind of the same problem of a 2D environment that results in problem with rangers in trees and wizards flying...there isn't some sort of way to have that allow for movement around the room, and likewise there isn't a way to tell if a rogue is flanking someone for a backstab or skill like this. However, on the whole I like the idea...silence an enemy so they can't call for help/cast w/o silent spell and add a skill that would presumably need synergy from other rogue skills to work.