Plateskirts are a type of armour worn mainly by meleewarriors in the leg slot. They are exactly the same in stats as platelegs but with a more feminine style, and are generally cheaper. Among Combat styles, plateskirts provide good defence against the range type but are more vulnerable magic.
They are less popular and consequently less expensive than the platelegs even though they share the same stats and weigh 1 kg less. Some players buy plateskirts instead of platelegs because they are cheaper and in less demand. In RuneScape Classic, the NPC Thrander could transform platelegs into plateskirts and vice versa for free.