[RPG] How does armor work in nWoD

You read the rules right, Armor in the nWoD (at least in 1e, which I am familiar with) works exactly the same as Defense, but with one key difference: it is not Defence. I know that statement seems odd, but it is important for numerous abilities, which I will touch on here:

All-Out Attack and charging (Core, p. 157 and p. 164):

Your character foregoes all pretense of self-preservation. He gives his all to do his opponent harm. You gain two bonus dice on your characterÕs attack for the turn, but lose his Defense trait for the turn.

Your character can move up to twice his Speed and stage an attack at the end of his movement, all in the same turn. Your character's Defense score is not subtracted from any attacks made against him in the turn. He makes a relatively easy target of himself by making a beeline to a specific opponent.

This is available for everyone, and quickly establishes why Armor can be fantastic. An heavily-armored landsknecht can go all-out with attacks every round because his armor does the job of his defence, while a lightly-armored fencer cannot afford to, or he can charge to cover more ground while still having damage reduction (even if Speed is reduced by the armor).

Environmental Conditions (Core, p. 155)

A target who is tied up, unconscious or simply unmoving does not receive Defense as protection. Nor does one who's taken by surprise or who is unaware of an incoming attack (say he has his back turned). If multiple close-combat attacks are directed at your character in the same turn, he may try to evade each of them, but doing so becomes progressively more difficult. Each attack after the first diminishes your character's Defense modifier by one.

Since melee attacks will be a significant portion of a medieval system, not losing your primary defenses when knocked prone or surprised or attacked by multiple opponents would be very beneficial. Armor takes the attacker from +2 (for being prone) to being +2 minus the Armor rating. A lesser use for it is for drawing weapons; drawing a weapon and using it in the same turn gives up Defense for that turn (without Quick Draw, of course), which doesn't hit someone who uses Armor as much. Other things that can reduce or eliminate Defense, but not Armor, include tear gas (not likely to see), the Feint Merit from Fencing, and the Destroy Defense Merit from Boxing and Kung Fu (Armory Reloaded).

Ranged attacks ignoring Defense (Core, p. 155; Armory, p. 90):

This automatic Defense does not normally apply against Firearms attacks. (See p. 164 for how they may be avoided.) The only instance in which Defense does apply against Firearms-based attacks is when the attacker shoots within close-combat range; within a yard or two of the target... Defense does apply normally against thrown weapons, such as rocks, knives and spears. A character may use either Athletics or Firearms to fire a bow... A character may use either Athletics or Firearms to fire a crossbow.

As you can see, Armor has another use in deflecting fire from arrows and bolts, which form a not-insignificant part of medieval warfare.

Better use of Merits

Rather than finding the quotes, I will simply list the various Merits that require sacrifice of Defense (there might be more in the Werewolf/Vampire/Mage/etc. books, I mainly know core and Hunter):

• Core: Boxing, Combination Blows and Haymaker; Kung Fu, Whirlwind Strike; Two Weapons, Focused Attack and Fluid Attack; Gunslinger, to aim at two targets (for hand crossbows).
• Armory: Chain Weapons, Whirl and Thrust; Combat Marksmanship, Rapid Fire (not useful unless you have a chu-ko-nu or other repeating crossbow).
• Armory Reloaded: Aikido, Ukemi; Entering Strike; Langschwert, Fool's Guard and Doubling Cut and Wrathful Cut (and Armored Fighting reduces penalties from Armor as well!); Shurikenjutsu, Choku Da-Ho and Ikki-Gokken; Berserker, Strength in the Fury (for All-Out Attack) and Ignorant in the face of Death and Bloody-Handed Bastard.

All told, Armor can have excellent benefits over Defense. Characters of that period who wish to maximize benefits from it are most likely to have Merit families like Two Weapons, Langschwert (and especially Armored fighting), or Berserker, but every melee-based character can benefit from all-out attacks and charging.

To specifically address your confusion on Leather (Hard) armor, you do not get a net bonus to your damage prevention, but you do get to keep the same bonus through many actions that would otherwise leave you defenseless. If you want an extra bonus, look at the leather armor from Armory, p. 177. It is the same as Core, but:

Some vanity outlets sell a stronger version of leather armor. This armor consists of leather scales or leather strips riveted over one another, making the armor tougher. Such riveted leather, sometimes called lamellar, costs ••, but offers a Rating of 2/0 against attacks.

and also offers heavier armor!

Plate Armor: Rating 3/2, Strength 4, Defense –2, Speed –3, Cost ••••; If plate armor is not fitted to the wearer (say, if a character simply picks up a set of plate armor from a museum or collection and tries to use the armor in battle), the character suffers a –3 Defense penalty and a –4 Speed penalty instead of the Traits above, though the armor still provides the Rating and Strength requirements listed.