Recommended armour classes. Never make an armour with class higher than 4,
unless the armour is not permanent, or is deficient in some other way.
Armours of other types then "armour" (helmets etc) should not have a class
higher than 1.

Name		class	value	weight	type
Helmet		1	75	1	helmet
Ring of prot	1	200	1	ring
Leather jacket	2	50	2	armour
Leather armour	3	110	3	armour
Chainmail	4	500	5	armour