Rather than just add to the wearer`s Endurance points, each piece of armour has its own Endurance points, equal to the EP bonus, which represents the armour`s durability. When taking damage in combat, the player may decide that the armour takes this damage instead, such as a helmet reducing damage to the head. For every 2 Eps that the armour absorbs, the armour itself is reduced by one EP. However, you may only reduce damage taken from one peice of armour when doing this. To simplify combats, npcs will use the usual rules - just add EP bonuses from armour to their total Eps. If any armour is taken from a slain foe, it is considered to be reduced to 0 EPs and so will need to be repaired.
For example, Bright Fox is wearing a chainmail waistcoat (4 EP) and helmet (2 EP). During a combat round, he takes 5 Endurance damage, and decides that this is a head hit, and he will have the helmet take the brunt of this attack ( he cannot also use his chainmail waistcoat, since the blow did not strike there) He reduces the damage by 4 points, but the Helmet is reduced to 0 EP and now needs to be repaired..
Armour may be repaired by someone with suitable skills. This often involves a trip to a blacksmith, with a typical cost of 3 GC per point of Endurance restored. Since players will be typically away from such services, they may find their armour in a terrible condition after a few battles.