Black wizard robe skirt (previously Black skirts) is one of the several skirts available to both free players and members. They are sold by Thessalia who runs her shop, Thessalia's Fine Clothes, in Varrock.
Black skirts were used to represent neutrality over the 10 December2007 updates.
Prior to the 31 January 2012 update, the black wizard robe skirt was known simply as "black skirt" and had no stats. This update gave both the blue and black versions a new name and a small stat boost.