If you are reading this and you've ever been witness to one of my gaming rants, then you probably know that I'm a fan of systems in which armor acts as a damage absorption system, and even if you've never met me, you might know it from some of my post on various sites such as www.seankreynolds.com. I simply find the concept of armor working to absorb damage to be more believable and interesting the armor that deflects blows.

D&D, on the other hand, is a system in which armor adds to an abstract value (AC) that serves to act as an all-or-nothing damage shield. Even by his description you an see how much I dislike this idea, and I think that there is more then enough room in the d20 system to wedge in some armor-as-DR mechanics without bogging things down. To that end I participated in a series of often heated debates on www.seankreynolds.com that ended up being the basis of one of Sean's rants, which can be found here.

Read that over and come back... if you are wondering, almost everything in blue came straight from me, or at least thats how I remember it three+ years on. Now we can get on with my rebuttals to Sean's comments, and I think it time given that I've changed some of my ideas and now am a lot more willing to accept some of what Sean had to say then I was back then.

Why Damage Reduction?

I think that before I delve deeper into this discussion it is important that I lay out clearly why I favor damage reduction over armor class: semantics. The d20 system is very bad at deciding what one of its abstract values represents and sticking to it. Armor Class represents your ability to dodge out of the way (bonuses from Dexterity) and your ability to absorb damage (bonuses from armor worn), however Hit Points are also defined as representing a character's ability to dodge out of the way and to take a beating. Although Hit Point adjustments are a little beyond the scope of this post, its important to know that I support abstraction, but abstraction with clearly defined boundaries. Thus armor acting as DR is just a small part of the larger setup I'd prefer to see:

Defense – Dodge attacks Armor – Reduces Damage Taken Hit Points – Represent real physical damage.

My Proposal

I've given up on weapons having Penetration scores... if for nothing else then to cut down on the bad jokes around the gaming table. Its also true that it represents a huge chunk of work for a standard D&D game, although I still think its a viable ability in a reworked system.

Given that, I think that armor should still give "AC", or a bonus to the chance to take no damage at all. Some armor is better at deflecting attacks then absorbing, while others are the opposite. My fast rule for this is split the bonus half and half between the two, favoring damage reduction. Even in full plate someone has a change of dealing damage (depending on Strength bonus and feat selection).

Notice also that I said "Armor", not "Bonuses to AC," meaning any armor should gain this, but not spells that increase armor class. One could extend this to "Armor Bonus" to include effects that specifically grant a bonus of that type. Natural Armor would be split along the same guidelines.

Not a big change is it? It can be done on the fly with very little prep work, but it gives the DM a way to draw a line in the sand and say "Here your attack was deflected, and here your attack couldn't get through your armor."

Balance

At most you are swinging the balance by a couple of points in the AC department. Fighters and the like that use armor will experience a small increase in the amount of hits they take, but they will be significantly dropping down the amount of damage they take from scores of minor wounds. Players do become slightly more vulnerable to huge damage hits, but these kind of attacks already tend towards the low chance to hit vs high damage scale so a few points on either side difference isn't going to matter much.

The only problem I can see with this rule is two-handed fighting and power attack. Basically, a fighter under this system might have his AC reduced by 3-4 for 3-4 DR, but someone with power attack and a 2 handed weapon can power attack for 3-4 more and gain 6-8 damage... not a good trade off at all, but is it really a failing of this system? I'm personally of the mind that Power Attack with 2 handed weapons is a bit overpowered so I'm not sure its a balancing point worth considering.

Why Bother?

True, the question at this point is why bother... but remember that I'm writing this as a simple rule to handle armor in D&D... if I were to create my own d20 fantasy system it would be much more akin to Iron Heroes or the like and feature a richer combat system... more on that to come :)