One of the more arcane-seeming things about Batmud is armour protection messages and coverage. You can see the progression of messages in ' help score'. There was a conversation on the newbie channel and Zerks gave the best explanation I've seen for how prots and coverage works on Batmud...

Wunjo [newbie]: why mu general protection goes suckier when I wear more stuff?
Porkzar {newbie}: prots "scale" with the coverage
Wunjo [newbie]: so how it works? it doesn't really tell the whole truth or general protection really gets worse?
Dralith the Helper <newbie>: 70% coverage with 1 item = awesome.. 80% with 10 items = not quite as awesome. If that makes sense
Wunjo [newbie]: so my gen prot should be still better when it's superb with just a few spots uncovered, than it would be UNGODLY with bit of half body cover, or something
Zerks {newbie}: The adjective just tells your protvalue compared to the protmax that you coverage gives you: Wear more armour without high protvalues -> coverage goes up and the ratio of your current prot vs coveragemax gets worse
Zerks {newbie}: your prots dont drop, quite the opposite. The ratio against your max you can utilize through coverage gets and adjective drops