Dwarven Plate Mail

The forged black iron plate made by the dwarves exclusively for their own warrior leaders is both heavy and unattractive by human and elven standards. However, dwarves have traditionally placed less emphasis on appearance than on personal defense. Dwarven warriors who wear dwarven plate are often called "waddling cauldrons" by their enemies due to the bulk of this armor.
High-quality dwarven plate is the boilerplate version of human plate armor. It is 50% heavier than equivalent mails, making a single suit of dwarven-sized plate mail armor weigh approximately the same as a set of human-sized plate mail. Additionally, the denser armor affords protection equivalent to plate mail +1, and the armor itself saves against equipment damage at +6, in addition to any bonuses permitted if the dwarven plate in question is also magically enchanted. Stories about dwarven plate armor withstanding the smelting fires of a red dragon's breath may be boastful exaggeration, but it is an established fact that dwarven plate often survives an attack that its wearer does not.
As mentioned, dwarves prize combat effectiveness over a warrior's appearance. It is therefore very rare for the iron appearance of dwarven plate mail to be adorned in any way.
Much like the elves, dwarves do not make dwarven plate for non-dwarves. Not only is it considered impractical to spend one's time building a suit of armor no dwarf can ever hope to wear (a waste of time), but the dwarves will admit to having no skill in working with the peculiarities of the human body. Dwarves tend to ignore things like flexible joints, as their range of movement is already restricted by nature. An ancient dwarven warrior's saying goes something like "If it doesn't fit, bend it. If it still doesn't fit, break it!" Along those lines, another popular dwarven saying is "Never let your armor impede a good fight."
Dwarven Field Plate Mail and Full Plate Mail do not exist. Not only would dwarves look like miniature iron golems when so protected, but dwarves prefer to let their facial expressions speak for them in combat. The problem of free movement plays a big part in this practical decision as well.
No human has ever managed to convince a group of dwarves to forge a set of full plate armor for them. If such a task were even to get past the bargaining phase, it would quickly become apparent to all concerned that the dwarves have no experience or knowledge of such constructions and lack the motivation to learn it. Dwarves themselves claim they'd rather be 'beating their hammers on orc skulls than beating them in the forge."
Curiously, gnomes have offered to give full plate their 'best shot" from time to time, but so far, no human has been brave or foolish enough to accept the offer. Dwarven plate mail lasts longer than its human counterpart. Dwarven plate mail can sustain twice as many points of damage as normal plate mail (if the optional armor damage point system presented in the Fighter's Handbook is being used).

Magical Dwarven Plate Mall

Magical dwarven plate mail is only as encumbering as ordinary plate mail. The enchantment is cumulative with the natural +1 to armor class dwarven plate possesses. Therefore, dwarven plate mail +1 is actually equivalent to ordinary plate mail +2 for purposes of armor class (but not saving throws). It may be easier for the DM and player if the base armor class for dwarven plate is remembered to be 1, equivalent to field plate armor for humans.