Armor

Armor, unlike most d20 systems, provides damage reduction rather than decreasing the chance to hit.
Multiple pieces of armor may be worn at once (provided you have the available equipment slots) and all of the Armor Bonuses from the different pieces are added together. To calculate the Max Dex penalty find the item with the lowest number, then average the remaining pieces (rounded down) and subtract that from the lowest Max Dex Penalty in the set, the difference between these two is then subtracted from the Max DEX of the lowest. The calculate the Skill check penalty round up the average of all the pieces of armor in the set.
Example: Fred wants to wear the Steel Skullcap, the Heavy Boots, and the Chainmail Shirt. The total Armor Bonus is 7 with all pieces added together, the Skill Check Penalty is 2 (average of 2, 2 and 1 rounded up), and the Max Dex is 2 (Chainmail Shirt has the lowest Max DEX of 3, the other two are 4 and 5 which averages out to 4 rounded down, and 4-3 is 1, which is subtracted from the Chainmail Shirt Max DEX of 3 to result in a Max DEX of 2).
Only characters with the Armored Tank feat may use Heavy Armor. Your total Armor Bonus may not exceed 12 (before factoring in magical and other bonuses).