Plate, Chain, Splint, Banded, Leather, etc. etc.. The selections of armor seem nice and simple. Go to the local Fighters Warehouse and grab a suit right off the rack ready for battle "I guarantee it".
Well as you may have noticed, simple doesn't always keep your players' attention too long.
The AD&D Fighters Handbook and Arms and Equipment Guide are excellent resources for describing armor and figuring out a piece-mail suit. Piece mail is normally thought of as an odd collection of ill fitting armor pieces. Not always true. How about a set of chain mail with polished plate shoulder pads and heavy black leather pants? It looks great but what a nightmare for the DM to figure out what AC to assign! We say, "Get rid of AC altogether!".
Here's how to use the box area system of damage to easily keep track of the different armor types. As shown in the DAMAGE text, Grog has a 15 Constitution. That gives him 15 boxes in each area. To figure out protection values for each area just add the number of boxes listed in the chart below.
*No additional boxes are allowed for shield. The shield is taken into account in the defense modifier.
If an armor area is filled with damage points it is rendered useless. Not the whole thing just that area. Two benefits: One, a character need only get that area of the armor replaced or repaired. (much less expensive) Two, the DM has a system for full player accountability regarding damage and if they remember to spend the time and money to fix the damaged armor.
Now, let's revisit the fashionable piece-mail suit mentioned earlier. (remember, Grog has 15 boxes per area with no armor) His legs are covered with Leather pants. (add one box per leg area) His torso and forearms are covered with Chain Mail. (add 4 boxes to each area) His shoulders (upper arms) are donned with Field Plate. (add 5 boxes to each shoulder area) And since Grog isn't too bright, he wears nothing on his head. (leave at 15 boxes)