# Armor Class vs. Damage Reduction - Your preference



## griffonwing (Jan 9, 2013)

I started out, like many players, with ADnD2e. I then moved on to 3e. The D&D franchise seems to cater towards the AC.  Heavier armor and Shields add to your target Armor number, making you harder to hit.  It can be argued that the bonuses for armor and shileds should be interpreted NOT that you are harder to get hit, but that you are harder to get hit with a strike that actually causes damage.  With this style, you either get hit with full damage, or you dont.  

I then started playing games that used DR instead of AC, and I find that I actually prefer DR over AC. In HackMaster, and other systems, all armors make you easier to hit, and shields practically guarantee a hit, since you are actively blocking with it.  You are much easier to hit, but the damage is greatly reduced.  This, to me, seems a much more realistic approach, and it's one that I favor above AC.

I suppose that you can, perhaps, house-rule AC  so that each armor type (light/med/heavy) gives a respective 2/4/6 point window of receiving half-damage. So, for example, if an orc misses your AC by 4 points or less, you take only half damage.  While this isnt as realisatic as DR, it does help offset the "full or none" unrealistic approach to AC.

What are your thoughts on AC vs. DR?  Which do you prefer?


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## delericho (Jan 9, 2013)

In principle, I agree with you that Armour-as-DR is somewhat more realistic.

In practice, I've found that Armour-as-DR creates a lot of problems (even in games designed to use it from the outset). Armour-as-AC just works better.

So I'll take Armour-as-AC, please.

YMMV, of course.


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## Janx (Jan 9, 2013)

delericho said:


> In principle, I agree with you that Armour-as-DR is somewhat more realistic.
> 
> In practice, I've found that Armour-as-DR creates a lot of problems (even in games designed to use it from the outset). Armour-as-AC just works better.
> 
> ...




I don't like the mathematical back and forth it causes between attacker and defender.  I never liked Paladium's Dodge mechanic either for the defender to roll after the attacker rolled.


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## Obryn (Jan 9, 2013)

I've found I don't much care... When it comes down to it, an armor-as-DR system needs to be built that way from the ground up, since it will cascade to attack rolls, hit points, etc. Armor as DR always feels like a clumsy hack to me in D&D whereas it seems natural in games like Earthdawn and WFRP2 because they're designed around it. 

I'm perfectly happy for different games to tackle the issue in different ways. 

-O


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## delericho (Jan 9, 2013)

Janx said:


> I don't like the mathematical back and forth it causes between attacker and defender.




Yep, that's my biggest objection. That, plus the seeming need of every Armour-as-DR system to then give weapons some sort of Penetration rating, allowing them to bypass some or all of the armour worn. The effect being that a damage roll then requires three subtractions, rather than one:

- In Armour-as-AC, you roll damage, then subtract it from hit points.

- In Armour-as-DR, you roll damage. They, you subtract the Pen value from DR, then subtract that result from the damage, and then subtract _that_ total from hit points.

It also gets very frustrating when you see most of your attacks being negated outright by the target's DR. Especially if you _also_ have difficulties hitting in the first place.

(WHFP 2e is a _great_ game, but I really hate that particular aspect of it - most of my monsters missed most of the time, most of the 'hits' were then either dodged or parried, and then most of what was left saw the entirety of their damage negated. And then, as if that wasn't annoying enough, the few times the damage wasn't negated entirely, it seemed to one-shot a PC every time. Dice behave strangely when I roll them!)

Finally, in the specific case of 3.5e, the Armour-as-DR rules quickly turned Power Attack into a game-breaking option. But that was a specific oddity because those particular rules weren't very good.


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## Cleon (Jan 9, 2013)

I quite like systems that use both - so an attack could miss (no damage), hit the AC (weapon damage minus armour DR) or slips through a gap in the armour (weapon damage ignores DR) depending on how good the relative rolls where.

Furthermore, I'd like their to be more of a roll for combatant's defensive skill. In regular AD&D a 1st level Dex 13 fighter in chain has an identical AC to a 21st level Dex 13 fighter in chain. Surely the high level fighter should have nigh godlike skills at parrying and dodging attacks? That's supposed to be (partially) covered by hit points, but the implementation of it sometimes doesn't gel very well with me. Why does it cost, say, 2d6 hit points to "dodge" a greatsword and only 1d6 to avoid a heavy staff? They are both more-or-less the same reach, speed and there's similarities in their weapon technique.

I handwave that away by viewing hit points as being some kind of chi "force field" that is literally absorbing the blows, since that seems the best fit I could come up with to the AD&D mechanics, but it doesn't have to be that way. It might work to have a "glancing blow" between a "miss" and an "AC hit" where the defendant spends a few hit points and parries/dodges the attack.

So the result of an attack might be something like this:

MISS (fails to beat Dex) => no damage
DEFENDED AGAINST (beats Dex, fails to beat Dex+Parry/Dodge) => reduced damage.
SOLID HIT (beats Dex+Parry/Dodge, fails to beat Dex+Parry/Dodge+Armour) => weapon damage minus DR.
PRECISION HIT (beats Dex+Parry/Dodge+Armour) => weapon damage.

However, I prefer a Parry/Dodge mechanism based on separate actions. e.g. you spend an opportunity attack to Parry a blow, or a move action to Dodge an attacker, and the success or otherwise is determined by some sort of contest (e.g. if you beat an opponent's attack roll with a parry roll you parry their assault and take no damage).

The problem is it's easy to make a system that's so complicated that it slows down play, and I'd want D&D combats to be quick and, preferably, simple. Or, if not simple at least intuitive enough to make decisions quickly.


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## Michael Silverbane (Jan 9, 2013)

I am ok with either type of implementation.  When using armor as DR though, I like for both armor and damage to be random, rather than one being random and the other static.


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## Cleon (Jan 9, 2013)

Obryn said:


> I've found I don't much care... When it comes down to it, an armor-as-DR system needs to be built that way from the ground up, since it will cascade to attack rolls, hit points, etc. Armor as DR always feels like a clumsy hack to me in D&D whereas it seems natural in games like Earthdawn and WFRP2 because they're designed around it.
> 
> I'm perfectly happy for different games to tackle the issue in different ways.
> 
> -O




Yes, I agree with all of that. Whichever you use it works better if it's one integrated system. Taking one approach (DR/AC) and bolting the other (AC/DR) onto it rarely works well.

Not that it stopped me trying now and again. I have a inordinate fondness for rulesmongering.


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## Cleon (Jan 9, 2013)

Michael Silverbane said:


> I am ok with either type of implementation.  When using armor as DR though, I like for both armor and damage to be random, rather than one being random and the other static.




Yes, random DR at least gives a chance for a feeble weapon to get through without having to crit, and it makes partial and full versions of an armour easier to model - e.g. a breastplate and helm over a suit of padding might be 1d8+2 DR, while a full coat-of-plate might be 1d4+6 DR. Both have max DR 10, but the full plate's thinner portions are a lot harder to get through than the lighter version.


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## Neonchameleon (Jan 9, 2013)

What do I want from the system?  If going for speed and drama, Armour Class every time.  If going for realism, option C: Rolemaster-style weapon vs armour charts.


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## Zaukrie (Jan 9, 2013)

Simple is my preference. So AC, or a simpler DR than we normally see.


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## Derren (Jan 9, 2013)

Armor as AC.

Dr does not make sense. Armor, while being able to, was never designed to soften hits but to negate them. That is what AC does. Unless you hit a weak point (beating the AC) you do no damage.


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## Ed_Laprade (Jan 9, 2013)

Both. Good armor should deflect some blows. But you need to have characters with fewer Hit Points in a DR system, or combat will take forever. And deciding on how deflecting 'some' blows works can get pretty complicated pretty fast, which is not good.


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## Olgar Shiverstone (Jan 10, 2013)

AC.  Simplicity is golden.


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## Mishihari Lord (Jan 10, 2013)

I prefer DR because it's more conducive to thinking of hit points as actual physical resilience than D&D's use of hit points as ablative plot armor.


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## DerekSTheRed (Jan 10, 2013)

I used to prefer AC to DR but then I played Savage Worlds. Everyone has natural DR in the form of their Toughness attribute with armor adding to it. This increases realism and allows for Savage World's best feature, no hit points (or very little hit points anyway). Since your not tracking every graze and scratch, DR ends up being much easier to do.


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## am181d (Jan 10, 2013)

Armor Class and the vague definition of Hit Points are my least favorite part of Dungeons & Dragons.


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## 3catcircus (Jan 10, 2013)

I prefer a third option:  Armor as penetrative divider damage reduction - armor has a value that gets multiplied by a weapon's penetrative value to result in an effective armor value that reduces damage.  I'd use the critical multiplier as the penetrative value instead of using it as a crit multiplier.

I also like the use of hit points, not as a "subtract until dead," but as a "compare damage taken to multiple set-points (multipliers) of your base hit points that result in varying damage effects, with an additional similar level of damage taken increasing the damage effect to the next level."

But - I also tend to prefer house rules where weapons do a fixed amount of base damage (typical 1-2 points for a knife, about 5 points for a sword, etc.) with a margin of success resulting from the dice roll added to the damage (i.e. need a 10 to hit and get a 12? add 2 to the damage you do), and where a margin of success of 5 or more is a critical success.

Ideally, I'd turn D&D into a dice pool system where you'd have combat skills, with more skill ranks equaling more dice being rolled.

So - an example would be a guy wearing chainmail being attacked by a guy with a sword.

The sword would have a base damage of 3 and a penetrative value of 2.  The guy wearing chainmail would have an AC of 2 (I'd divide current AC values by half), so the armor would stop 4 points of damage.  

The average guy could hit but not do any damage if he just hits.  Beats the roll to hit buy at least 2 and you'll do a single point of damage.  Beat it by 5 or more and it'd be a critical success, doing twice the total amount of damage.  

Using a dice pool system, I'd also make each additional die that is a success add 2 to the margin of success (i.e. need to roll a 10 or better and 3 dice are a success, with the most successful being 3 better?  your margin of success is 3 + 2 + 2), resulting in (the above example) 10 points of damage.

But in order to make this work - I'd make base hit points only a factor of STR and CON, and have the set-points be 1 pt of damage, base, base x2, and base x3.


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## Dioltach (Jan 10, 2013)

Since my games tend to veer away from the traditional medieval-style fantasy, I prefer a class-related Defence bonus with light armour offering DR.


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## Gilladian (Jan 10, 2013)

Gaaah! Some of these answers make my head swim! If it takes 3 minutes to do the math for each blow, it is WAAAYYYY too complex. 3 math operations is too many. One is plenty for my players. 

Also, D&D has always used AC. If you want to use something else, find another game where it is the basis of the armor system. Don't wreck my D&D!


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## RangerWickett (Jan 10, 2013)

So first you calculate the vector angle at which the attacker can hit the target. A halfling that is adjacent to a human might fill up 45 degrees of his field of vision, as opposed to 20 degrees farther away.

Then determine whether the attack is a radiating line like a rapier, or a plane segment like the path cut by a sword.

If the former, multiply the attacker's accuracy rating by the percentage of 180 degrees that the target takes up.

If the latter, program a 3D graphing calculator to track the intersection swath along the possible paths of the swinging weapon. Multiply the attacker's accuracy rating by the ratio of a hemisphere's volume.

Next, plot a random table with hit locations based on the odds above. Make the attack roll, and based on the table determine if it misses, and if it hits what location.

From there, the rest is far less straightforward. It'll all be detailed in my upcoming book.


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## TerraDave (Jan 10, 2013)

delericho said:


> In principle, I agree with you that Armour-as-DR is somewhat more realistic.
> 
> In practice, I've found that Armour-as-DR creates a lot of problems (even in games designed to use it from the outset). Armour-as-AC just works better.
> 
> ...




This, BUT



DerekSTheRed said:


> I used to prefer AC to DR but then I played Savage Worlds. Everyone has natural DR in the form of their Toughness attribute with armor adding to it. This increases realism and allows for Savage World's best feature, no hit points (or very little hit points anyway). Since your not tracking every graze and scratch, DR ends up being much easier to do.




Sure, if its a totally different game, then it can work! I think the toughness save in Mutants and Masterminds works in a similar way.


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## Agamon (Jan 10, 2013)

I'm with the folks that prefer simplicity over realism.  Abstraction is fine, and in fact better for allowing wider range of description of a blow.  I like WHFRP2 and Hackmaster, but I still prefer armor as AC.


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## Smoss (Jan 11, 2013)

Like the OP, I started in 2e and went to 3e. I was building my own systems before 3e came as 2e didn't do what I wanted.

I started with multiple ACs (armor Class and Defense Class). Similar to the direction SW Saga and 4e went. This worked, but wasn't good enough.

When 3e came, I liked it a lot. I enjoyed DR and tried armor as DR. This had issues but I liked the idea.

My final solution was a damage threshold that armor adds to (Base threshold based on CON). It works very similar to Savage Worlds when it comes to damage. Beat the threshold (Do enough damage) and you actually hurt the person. Do not and you do not. (I also eliminated hit points. I hate hate hate HATE bookkeeping. Minions was the one thing I really liked about 4e, much like mooks in Savage).

I've since tweaked my system to be as realistic feeling as I could with as little math and such as possible for speed. It is as close to perfect for my use as I can get it without either massive math or sacrificing brutal realism.  (I also found a way to have fast and easy lopping off of limbs and such too. So yeah, battles can be gruesome)

Smoss


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## timASW (Jan 11, 2013)

armor as AC sucks. I've houseruled it away since AD&D 2e and the method hasnt changed much in all those years because its simple and easy. 

Defense score = 10+Dex+shield+BAB
DR= armor + CON bonus. 

Attack roll that beats the defense score hits and does damage per the weapon type plus the amount by which the attack roll beat the defense score. (sometimes i use 1/2 that amount, depends on how lethal i want combat to be). 

Critical hits ignore DR entirely. 
Con no longer adds to HP. (often HP are also reduced, again depending on how lethal i want it to be.) 

Its simple, easy and gives me plenty of dials to turn depending on the feel of the campaign i want. I've also gone back and forth between the defense score being a static and being an opposed attack roll. I've found I slightly prefer it as a static # but I can go either way depending on how the players vote.


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## 3catcircus (Jan 11, 2013)

timASW said:


> armor as AC sucks. I've houseruled it away since AD&D 2e and the method hasnt changed much in all those years because its simple and easy.
> 
> Defense score = 10+Dex+shield+BAB
> DR= armor + CON bonus.
> ...




Regardless of whether you use AC, DR, Active Defense, the single biggest factor in making things simple is to end the AC, BAB and hit point arms race - it looks like you've limited your bonuses to both defense and DR - do you stack any bonuses from magic, natural armor, etc.?  I also like that it looks like you limit damage bonuses to only the amount you succeeed by - do you stack any magic bonuses or STR bonuses?


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## Li Shenron (Jan 11, 2013)

Maybe I would prefer worn armor as AC bonus (representing covering weak spots) and natural armor as DR (representing tough hide of certain creatures), but I've never used this, just armor as AC because of its simplicity.


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## Hand of Evil (Jan 11, 2013)

Run me over because I am in the middle of the Road.  

It comes down to the type of game you are running, sometimes armor = AC is a good thing and sometimes DR is a good thing.  Example for me, a fast pulp type game, where armor is not that common, I could see DR as the best way to handle it.  A game of fantasy combat and tough monster, with lots of weapons and armor, AC.  You have to look at flavor and balance.


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## Jhaelen (Jan 11, 2013)

My favorite combat system is still the original Runequest one. Imho, it manages to find the happy medium between realism and playability. Incidentally, it models armor as DR, so that's my preference, I guess.


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## shadowgames (Jan 11, 2013)

I prefer armour to have damage reduction rather than a set number to beat. I quite like the way armour is dealt with in Song of Ice and Fire roleplaying game.


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## timASW (Jan 11, 2013)

3catcircus said:


> Regardless of whether you use AC, DR, Active Defense, the single biggest factor in making things simple is to end the AC, BAB and hit point arms race - it looks like you've limited your bonuses to both defense and DR - do you stack any bonuses from magic, natural armor, etc.?  I also like that it looks like you limit damage bonuses to only the amount you succeeed by - do you stack any magic bonuses or STR bonuses?




Most enhancements add to defense score. Things like luck bonuses and deflection bonuses do that. 

Enhancement bonuses add to whatever they are placed. Armor to DR and shields to Defense. Or damage to weapons. 

Natural armor adds to DR but I tone it down quite a bit when it comes to monsters on that. I basically look at them and decide what sort of human armor their defense should be equal to. So you pretty much never see natural armor over 9. 

Str bonuses do add to damage but not to attack rolls. 

One of the things I've found works too is to pretty much cap magic items untyped bonuses at +3. You can find stuff over that but it takes an epic level caster to create so its very rare and much more expensive then in the book. You can however add things like flaming to plus 3 weapons so that you see more weapons with a sort of personality and feel then normal.


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## Zhaleskra (Jan 11, 2013)

Gilladian said:


> Gaaah! Some of these answers make my head swim! If it takes 3 minutes to do the math for each blow, it is WAAAYYYY too complex. 3 math operations is too many. One is plenty for my players.




That's laziness, not complexity. Not that there's anything wrong with laziness, just don't confuse it for complexity. Also, it's probably in your best interests not to tell people to find another game just because they want to house rule an aspect of it to work the way the want it to.


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## Argyle King (Jan 11, 2013)

Much like the OP, I started with D&D.

After trying other games, I found that I prefer DR.  Among the reasons why are I found that the bloated HP of D&D wasn't needed anymore; also, I found that I preferred games with active defenses.  I prefer being able to dodge, parry, or block rather than just standing there and getting hit because the opponent rolled higher than my AC.


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## El Mahdi (Jan 11, 2013)

deleted


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## timASW (Jan 12, 2013)

El Mahdi said:


> I prefer armor as AC also, but mostly because of it's simplicity and speed of play (however, I'd be willing to experiment with something like what Cleon posted).  AC makes sense, but doesn't perfectly model protection or damage either.  However, I can't simply pass by statements that are obviously incorrect.  That is, incorrect unless you meant to say that DR doesn't make sense _to you,_ or something to that effect...
> 
> DR does make sense, or at least just as much sense as AC from a modeling perspective.  Armor both negates some attacks and mitigates others...especially softer and flexible armors, including mail.  In real life, taking a hammer blow while wearing mail and padding is going to hurt, though not as much as it would if one wasn't wearing mail and padding...that's not negation, that's mitigation (or as expressed, "softening" the blow).  Neither AC nor DR perfectly model Armor.  Both highlight different factors, and model those factors accurately, but neither model _all _factors of armor in a comprehensive and realistic manner.
> 
> Personally I'd love a simple system that incorporates all factors in a realistic manner, I just don't think that system exists or is even possible.  It seems that simplicity may always be on the opposite end of the spectrum from realistic modeling (also know as _making sense)_.  The sweet spot on that spectrum is likely going to be different for most every person.  I think that's where the beauty of D&D Next having modular subsystems for this kind of thing is awesome.  Call it sweet _spot à la carte_.




I've tried playing around with systems that combine DR and AC in armor. Something like hard armors adding a few points to AC and a few points to DR and soft armors being almost all DR. it was okay. Somewhat realistic in the way that armor works as well. I just never wanted to go to the trouble of creating the way that magic and masterwork work in such a system. 

If someone came up with a good one though it would be pretty ideal for the stimulationist in me.


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## DanotheSlender (Jan 12, 2013)

My buddies and i once created a combat system that involved armor as damage mitigation, and relied on a dex/level basis for AC..if i remember right it worked pretty well, because while heavier armors slowed you down they mitigated a lot more damage than the lighter armors...take the ranger type guy in leathers vs. the pure fighter in banded mail, ranger had an ac of 16 and his leather armor (light armor no penalty) mitigated the first 1d4+2 points of damage delivered to him, so fighter hits for 10 with his sword and the armor took 5 points away, meanwhile the banded mail mitigates 1d10+2 damage, but lowers ac by 4 (heavy armor -4 to AC) fighter guy has an ac of only 11 so easier to hit but also harder to damage.
Worked pretty good for us back in the day. One of our not so regular group members really didn't like it because he hadn't had a hand in helping us work out all the fiddly bits. He was quite the vocal rules lawyer...


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## Razjah (Jan 12, 2013)

I think I prefer armor as AC, just for simplicity. I really want to find a system that handles Armor as DR simply and quickly, but I just can't find it. I've seen some ideas posted in this thread that look like interesting ways to handle this. 

Does anyone have experience with the Unearthed Arcana version of DR*? I don't think it works well enough in high levels, but for something like E6 I see it being nice. Especially if magic items are made much rarer than typical D&D.

*I'm sorry if someone already posted this, I must have missed it.


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## Argyle King (Jan 12, 2013)

Razjah said:


> I think I prefer armor as AC, just for simplicity. I really want to find a system that handles Armor as DR simply and quickly, but I just can't find it. I've seen some ideas posted in this thread that look like interesting ways to handle this.
> 
> Does anyone have experience with the Unearthed Arcana version of DR*? I don't think it works well enough in high levels, but for something like E6 I see it being nice. Especially if magic items are made much rarer than typical D&D.
> 
> *I'm sorry if someone already posted this, I must have missed it.




There are some systems which don't have levels at all.  The amount of DR something gives is just a number based upon what the armor is.


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## Razjah (Jan 12, 2013)

Johnny3D3D said:


> There are some systems which don't have levels at all.  The amount of DR something gives is just a number based upon what the armor is.




I wasn't clear enough in my post. I meant d20 systems that handle armor well. I like the way armor works in Savage Worlds and in Burning Wheel, but most of my experience is in 3.5, Pathfinder, and 4e.


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## 3catcircus (Jan 12, 2013)

Razjah said:


> I wasn't clear enough in my post. I meant d20 systems that handle armor well. I like the way armor works in Savage Worlds and in Burning Wheel, but most of my experience is in 3.5, Pathfinder, and 4e.




Pretty much all of the D&D/d20 rules, regardless of game, stink when it comes to handling of armor if you are looking for anything more than a "this arbitrary number meets that arbitrary number" in that there is no "reason" for why the numbers are what they are other than trying to scale with the BAB/AC/hp arms race.

The only way I've seen is to whole-sale throw away those mechanics and go with something else.

As I indicated earlier, a system that uses a low number for an armor's "AC" value that is factored against a weapon's penetration to determine how much damage is reduced when hit seems to work well.  

Of course, you have to throw away the idea that AC = 10 + armor + dex + shield + bonuses and that a successful hit = d20 + BAB + STR (or DEX) + bonuses > AC, _and_ that damage = random number + STR + bonuses leading to death is hp - damage until hitting zero (or some lower number).

I've thrown away the entire combat system as such and gone with the following (blatantly stealing pieces from the REFLEX system and the Spycraft 1.0 Shadowforce Archer system):

AC = armor + shield + dex + bonus.
DR = armor / 2
base hp = [10 + STR + (2xCON)]/4.  Wound levels occur at multiples of the base hp.  
successful to-hit = d20 rolled *lower* than controlling attribute (STR or DEX) + skill ranks - opponent's AC
number of d20s rolled to-hit = multiples of 4 ranks in the combat skill(s) - 1-4 ranks = 1d20, 5-8 ranks = 2d20, etc.  Margin of success adds (how much better than the target to-hit number) adds to damage, and multiple successes beyond the first add an additional 2 to the total margin of success.
No skill (i.e. non-proficient in the weapon) means you roll 2d20s and pick the highest roll.
Feats in the weapon automatically give you 4 skill ranks in the attack skill for the weapon group (I'm lazy and just use the Simple, Martial, and Exotic groups rather than the alternate weapon groups).
If you hit, damage = fixed damage value for the weapon + bonuses + the amount you roll lower than the needed to-hit roll.  The weapon's penetration is the current critical multiplier.

Example below:  A standard d20 Orc vs. a standard 1st-level Human Fighter wearing with a 16 STR, DEX 12, 15 CON, chainmail, with a lt. steel shield and a longsword.

The Orc has the following relevant stats:

AC = 3
DR = 2 (1.5 round up)
base hp = [10 + 17 + 22]/4 = 12.  Damage track = 1, 12, 24, 36.
Weapon = falchion (base damage = 4, penetration = 2).

Human Fighter has the following stats:

AC = 7
DR = 4
base hp = 14, track = 1, 14, 28, 42
weapon = longsword (damage  = 4, penetration = 2)

The Fighter wins initiative and attacks first.  He has proficiency but no extra skill ranks, so he rolls 1d20L.  He has to roll lower than a 17 (STR 16 + 4 skill ranks minus AC 3).  If he does so - let's say he rolls a 14.  He does damage of 4 + 3 (the amount he rolled lower than 17) + 3 (STR Bonus) for a total of 10 points.  The sword has a penetration of 2 and the Orc's DR is 2, so it reduces the damage down to 6 points.  The damage is greater than 1 but less than 12, so the orc suffers a slight wound, which means that the amount of d20s the orc rolls reduces by one level (i.e. instead of rolling 1d20L to hit, he has to roll 2d20H.

So now it is the orc's turn.  He has to roll 2d20H and get lower than a 14 (STR 17 + 4 skill ranks minus AC 7).  Not too bad even with the one level of wounds.  Let' say he manages to roll a 9 and a 10.  Well - his margin = 14 - 10 = 4,  So - he hits and does 4 (+ 3 Str) points of damage, minus the 8 points due to the fighter's armor (DR value * weapon's pen value), resulting no damage to the fighter.

Next round, the fighter rolls his 1d20L and scores another hit, doing a total of 4 points of damage - since the orc already has one slight wound, a second slight wound bumps his wound category up one level to moderate (but additional wounds of the same level don't) - now the orc has to roll 3d20H instead of 2d20H and must roll a fortitude save (target = CON of 12 + the FORT Save bonus of +3 which is a total of 15) or go into shock.  With 3d20H, he rolls an 18, 14, and 8 and has to pick the 18 = so he fails by 3 and goes into shock.  Now, due to being in shock, he has to roll a Will save each subsequent round in order to act.  The orc attacks and misses.

Next round, the fighter presses the attack and decides to use his power attack (up to the number of skill ranks) and so his target number is 16 - 3 = 13.  He rolls 1d20L and gets a 7 - a critical!  He does a total damage of (4 (weapon base) + 3 (STR) + 4 (power attack)) x 2 (crit) = 22 points of damage - minus the 4 points of DR = 18 points - a moderate wound.  That is the 2nd moderate wound since the orc's wound level already bumped up to moderate last round - making this a serious wound.  The orc now has to roll 4d20H on actions, and has to roll his FORT save.  But wait - the previous shock results indicate that any action that puts a character into shock makes him unstable instead (i.e. he begins to bleed out).  The orc rolls his FORT save (14, 3, 20, 2) - his 20 not only fails (making him go unstable instead of just going into shock) but the margin of failure is 5 or more.

The orc rolls his WILL save (target number = WIS of 7 + his -2 penalty) - he rolls 12, 12, 18, 6.  Yep - he can do nothing this round and goes unconscious.  The next round, the fighter stands there and watches him bleed.  The orc lays there, while unconscious and unstable - since he is unstable, his wound level increases by one level each full round - so the orc is now critically wounded.  The next round (while the fighter rifles through the orc's pockets to find the pie), the orc's wound level increases again and he dies.

As you can see - with this system, you don't have to worry about massive armor class bonuses (even an adult black dragon's AC becomes only a 17 (natural, size) - difficult, but not impossible when you consider that at those levels, a PC will likely have a STR of 25 and 10 or more skill ranks, so the to-hit number becomes 18) and the dragon has a DR of only 9 (Natural / 2).  Likewise, that dragon's hit points (and track) are 1, 18, 36, 54 - also difficult but not impossible to defeat.  Of course, the fact that that dragon, on a successful hit does a minimum of 12 points on a bite, 7 per claw, 6 per wing, and 10 per tail slap means it is still terrifying to deal with, not to mention the damage from the acid (I halve the average damage value for all area attacks).


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## Razjah (Jan 12, 2013)

That looks solid, but it seems like it would play slow at the table. Does it? Or did it until your group got used to the math?


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## 3catcircus (Jan 12, 2013)

First - I messed up the orc's first attack in my example - his rolls (after being wounded) should've been 9 and 14, rather than 9 and 10...  Mea Culpa.

As to how fast it plays - all the work is on the DM and players _before_ hitting the table if they are smart - no different than the detail on the existing character sheet, with the exception of adding the wound level chart, if desired (rather than making the DM tell you each time), and that the DM has to convert all the monsters and NPCs.  In practice, it works about as fast as regular d20 until you get up to high level play, at which point it is quicker since you are pretty much still doing single-digit math rather than double or triple-digit math and there is no running total of hit points to keep track of (quick, how many hit points are left if you start out at 167 and take 12, 32, 15, and 27 points of damage, from a claw, two bites, and a club (with 12 of the 27 points being electrical), during a single round of combat each reduced by DR 5/piercing and having Energy Resistance (electrical) 5?  Even if counting up rather than down, it still takes some time).

There are a few considerations:  

1.  How do you balance the need to provide skill points to add to your attack skill with the weapon (groups) while not short-changing the other skill points the players want to spend? I decided that the player can add up to half his skill basic ranks (i.e. the base he gets each level without the Int mod) into attack skills, with no additional skill points to offset the amount spent - it is a decent balance and forces players to make some hard decisions at level up time.  

2.  Can you substitute the BAB progression instead (i.e., when in normal d20, when your BAB hits +5, you roll 2d20L, when it hits +9, you roll 3d20L, etc.)?  You could, but then I'd not use attack skills - which may be preferable if you don't want to deal with players keeping track of yet another skill.  You still need to keep the "max ranks per level" regardless of which option you choose, though, to prevent runaway players...

3.  What to do about iterative attacks?  I just drop them - when, for example, the fighter hits 6th level, he'd get +6/+1 and his first iterative attack, but in the house rules I'm using, he is likely already rolling 2d20L at 5th level.

3.  What to do about feats that affect combat bonuses?  I just use them as-is except they affect anything that adds to a standard d20 roll affects the target number instead  (i.e., using Full Plate when not proficient lowers the to-hit number, Dodge still boosts your AC by 1, Weapon Focus raises your to-hit number by 1, etc.)

Now, my next exploration is to see how using HARPs development points based upon attributes rather than a fixed "x + Int mod" skill points works, since it ties the skills and attributes together (i.e., a PC with an 18 STR could take a total of 8 skill ranks in any skill using STR as the controlling attribute, for example.  So a PC with the array of S16 D12 C15 I11 W8 Ch9 could take a total of 6 STR skill ranks, 2 DEX skill ranks, 5 CON skill ranks, 1 INT skill rank, and no ranks in WIS or CHA skills.  That is up to 6 ranks in any combo of Climb, Jump, Swim, Melee Attack; 2 ranks in any combo of Balance, Escape Artist, Hide, Move Silently, Ride, Sleight of Hand, Tumble, or Ranged Attack, etc.)


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## 3catcircus (Jan 12, 2013)

First - I messed up the orc's first attack in my example - his rolls (after being wounded) should've been 9 and 14, rather than 9 and 10...  Mea Culpa.

As to how fast it plays - all the work is on the DM and players _before_ hitting the table if they are smart - no different than the detail on the existing character sheet, with the exception of adding the wound level chart, if desired (rather than making the DM tell you each time), and that the DM has to convert all the monsters and NPCs.  In practice, it works about as fast as regular d20 until you get up to high level play, at which point it is quicker since you are pretty much still doing single-digit math rather than double or triple-digit math and there is no running total of hit points to keep track of (quick, how many hit points are left if you start out at 167 and take 12, 32, 15, and 27 points of damage, from a claw, two bites, and a club (with 12 of the 27 points being electrical), during a single round of combat each reduced by DR 5/piercing and having Energy Resistance (electrical) 5?  Even if counting up rather than down, it still takes some time).

There are a few considerations:  

1.  How do you balance the need to provide skill points to add to your attack skill with the weapon (groups) while not short-changing the other skill points the players want to spend? I decided that the player can add up to half his skill basic ranks (i.e. the base he gets each level without the Int mod) into attack skills, with no additional skill points to offset the amount spent - it is a decent balance and forces players to make some hard decisions at level up time.  

2.  Can you substitute the BAB progression instead (i.e., when in normal d20, when your BAB hits +5, you roll 2d20L, when it hits +9, you roll 3d20L, etc.)?  You could, but then I'd not use attack skills - which may be preferable if you don't want to deal with players keeping track of yet another skill.  You still need to keep the "max ranks per level" regardless of which option you choose, though, to prevent runaway players...

3.  What to do about iterative attacks?  I just drop them - when, for example, the fighter hits 6th level, he'd get +6/+1 and his first iterative attack, but in the house rules I'm using, he is likely already rolling 2d20L at 5th level.

3.  What to do about feats that affect combat bonuses?  I just use them as-is except they affect anything that adds to a standard d20 roll affects the target number instead  (i.e., using Full Plate when not proficient lowers the to-hit number, Dodge still boosts your AC by 1, Weapon Focus raises your to-hit number by 1, etc.)

Now, my next exploration is to see how using HARPs development points based upon attributes rather than a fixed "x + Int mod" skill points works, since it ties the skills and attributes together (i.e., a PC with an 18 STR could take a total of 8 skill ranks in any skill using STR as the controlling attribute, for example.  So a PC with the array of S16 D12 C15 I11 W8 Ch9 could take a total of 6 STR skill ranks, 2 DEX skill ranks, 5 CON skill ranks, 1 INT skill rank, and no ranks in WIS or CHA skills.  That is up to 6 ranks in any combo of Climb, Jump, Swim, Melee Attack; 2 ranks in any combo of Balance, Escape Artist, Hide, Move Silently, Ride, Sleight of Hand, Tumble, or Ranged Attack, etc.)


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## JustinAlexander (Jan 14, 2013)

griffonwing said:


> What are your thoughts on AC vs. DR?  Which do you prefer?




If the system uses D&D-style, inflationary hit points to represent a character's ability to mitigate damage (as explained here), I prefer AC. Trying to use the DR system in combination with inflationary hit points tends to (a) break the model and (b) produce wonky effects on gameplay.

If you're using a non-inflationary hit point system or a wound system which is directly modeling physical damage, armor-as-DR tends to work better. But it still carries the "system tax" of adding an extra step to combat calculations.


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## griffonwing (Jan 14, 2013)

JustinAlexander said:


> If you're using a non-inflationary hit point system or a wound system which is directly modeling physical damage, armor-as-DR tends to work better. But it still carries the "system tax" of adding an extra step to combat calculations.




I think DR works very well with HackMaster. Certain weapons have a DR bypass vs heavy armor OR monster over DR+5.  For example, a flail or warhammer ignores 1 DR and a military pick or mace ignores 2.

Also, in regards to HP, you only gain a new hit-die every odd level. Every even level, you reroll and either overwrite your prev roll (if higher) or take half max if you failed both before.  For example.  You have 20 HP and you raise to Level 3; you roll class HD (d10) and you get 2.  You have 22 HP.  Level 4, you reroll.  If you roll a 1 -5, your HP raises to half HD; 25.  If you roll a 6-10, your previous (level 3) roll changes to current (20 + current).  If, however, his first roll was 8, his HP would not increase at level 4 unless he rolled a 9 or 10. It sounds a bit confusing, but it takes longer to explain it than to put it in practice. It helps to keep the power level from skyrocketing.

So, for all classes, the reroll (minium half) helps to offset the horrible HPs that can result of botched rolls.  How many times have you seen a Mage in D&D with more HP than a Fighter due to the fighter rolling 1s and 2s every level.  This ensures that even should the player roll nothing but 1s, his HP should be at least half of the max of the class norm.

So, yes, the HP is inflationary, however, only at half the level as other game systems, and it has various ways to keep the powers in check.


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## Wednesday Boy (Jan 15, 2013)

It's old and primarily relates to D&D but I find this argument reasonable.
http://www.seankreynolds.com/rpgfiles/rants/armorasdamagereduction.html


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## Argyle King (Jan 18, 2013)

Wednesday Boy said:


> It's old and primarily relates to D&D but I find this argument reasonable.
> http://www.seankreynolds.com/rpgfiles/rants/armorasdamagereduction.html




I find it reasonable in the context of D&D, and at the end of it he seems to make it clear that he was speaking with D&D in mind.  Outside of D&D, a lot of the things he mentions as problems are handled and handled very easily by some of the games which use DR systems.


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## Argyle King (Jan 18, 2013)

Wednesday Boy said:


> It's old and primarily relates to D&D but I find this argument reasonable.
> http://www.seankreynolds.com/rpgfiles/rants/armorasdamagereduction.html




I  find it reasonable in the context of D&D, and at the end of it he  seems to make it clear that he was speaking with D&D in mind.   Outside of D&D, a lot of the things he mentions as problems are  handled and handled very easily by some of the games which use DR  systems.


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## 3catcircus (Jan 19, 2013)

Johnny3D3D said:


> I  find it reasonable in the context of D&D, and at the end of it he  seems to make it clear that he was speaking with D&D in mind.   Outside of D&D, a lot of the things he mentions as problems are  handled and handled very easily by some of the games which use DR  systems.




Based upon how we've done it in our D&D game, it really doesn't seem to be a problem at all.  You just have to wrap your head around a few ideas that seem non-intuitive at first:

1.  Use of dice pools seems to be a must as it drives probabilities far better than a single d20 roll to-hit.
2.  DR needs to be a value factored off of AC while AC values remain the same and not just doing the "AC is now half what it was when using normal rules."
3.  The use of a weapon penetration multiplied by DR to determine how much damage is reduced works far better than just reducing damage by DR.
4.  Making hit points based off of physical attributes that does not increase with level is an important aspect of this, along with the idea of having multiples of your hp as trip points for wound levels that slowly affect your ability to act (and that then avalanches as the wounds accumulate) works very well with this.

I freely admit I pretty much lifted most of these ideas whole-sale from another game system and adapted them to d20, but they work.  They are far more interesting in play than the current d20 rules and readily lend themselves to using damage reduction.  

As to the argument of "are they worth the trouble?"  Well - at this point, the d20 rules, to me, seem extremely bland and devoid of "soul."  Mechanics that take a bit more of an organic approach and try to apply some thought into why the numbers are doing what they are doing are far more appealing to me.  As far as I can tell, as implemented in d20, DR is really nothing more than a way to artificially inflate hit points so that NPCs and monsters can go a few more rounds in combat as the player's BAB, hp, and AC continue to increase.


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## JamesonCourage (Jan 19, 2013)

delericho said:


> Yep, that's my biggest objection. That, plus the seeming need of every Armour-as-DR system to then give weapons some sort of Penetration rating, allowing them to bypass some or all of the armour worn.



In my RPG, armor adds to AC and usually gives DR as well. And yes, certain weapons have an armor penetration rating (or weapons can be built to add it).


delericho said:


> - In Armour-as-DR, you roll damage. They, you subtract the Pen value from DR, then subtract that result from the damage, and then subtract _that_ total from hit points.



This is something you essentially need to do once, in my experience. And, if the AP (armor penetration) doesn't outpace the DR, you just add it to damage. So if you did 1d10+8 (4 AP) against DR of 10, you'd essentially roll 1d10+2 (1d10+8+4-10). Easy for us, and you really need to do it once. And, if the AP beats the DR, then you just roll normal damage. So, 1d10+8 (4 AP) vs DR 4 means you roll 1d10+8. Again, easy for us.

Though I get why this still won't appeal to some people. I also have both the attacker and defender roll opposed checks, and while it doesn't take my group any longer than normal, I get why people may not like it.


delericho said:


> It also gets very frustrating when you see most of your attacks being negated outright by the target's DR. Especially if you _also_ have difficulties hitting in the first place.



I can also see this, even if it doesn't sway me, personally. It might be a little frustrating, but winning that fight is amazing, for my group. It's like almost dying; being knocked unconscious might be frustrating, but the fight being won and it being close is a lot of fun. The possible temporary frustration is worth it; this mindset also means we expect it, and it's less frustrating. It's part of the fun, now.


delericho said:


> Finally, in the specific case of 3.5e, the Armour-as-DR rules quickly turned Power Attack into a game-breaking option. But that was a specific oddity because those particular rules weren't very good.



Yep, and this leads me to agree with others: the system should have armor-as-DR in mind when designed, not tacked on afterwards. There's usually just too many problems that come from it, especially in systems like 3.5, where damage varies wildly when you compare level 1 to level 15. As always, play what you like 



Gilladian said:


> Gaaah! Some of these answers make my head swim! If it takes 3 minutes to do the math for each blow, it is WAAAYYYY too complex. 3 math operations is too many. One is plenty for my players.



Like I said above, you really only need to calculate it once per fight. Though, again, I understand if that doesn't appeal to you.


Gilladian said:


> Also, D&D has always used AC. If you want to use something else, find another game where it is the basis of the armor system. Don't wreck my D&D!



This isn't a D&D thread, it's tagged "RPG". As always, play what you like


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## steenan (Jan 19, 2013)

I don't have a preference for armor as AC or armor as DR. DR fits some games better, AC fits others. And in some games, the best implementation of armor is adding to HPs, negating a single hit every combat or something else entirely. 

For me, it's not really what armor does, but how it corresponds with the rest of the combat system.


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## delericho (Jan 19, 2013)

JamesonCourage said:


> This is something you essentially need to do once, in my experience. And, if the AP (armor penetration) doesn't outpace the DR, you just add it to damage. So if you did 1d10+8 (4 AP) against DR of 10, you'd essentially roll 1d10+2 (1d10+8+4-10).




That only works if both the AP and the DR are known. However many DMs (myself included) prefer not to reveal the exact capabilities of the monsters the PCs are facing - AC, hit points, etc (which would include armour-DR if I used it - indeed, it _does_ include 'normal' DR for those monsters who have it!)

But if it works for you, that's great. As you say: Play what you like.


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## stevelabny (Jan 20, 2013)

I prefer systems with a DR component because it gives more flavor to monster/armor types AND (most importantly, especially in the case of D&D) weapon types.  Its sad when weapons are relegated to just damage numbers and range/melee and there's no real advantage to one over the other.


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## JamesonCourage (Jan 20, 2013)

delericho said:


> That only works if both the AP and the DR are known. However many DMs (myself included) prefer not to reveal the exact capabilities of the monsters the PCs are facing - AC, hit points, etc (which would include armour-DR if I used it - indeed, it _does_ include 'normal' DR for those monsters who have it!)



That's true. My RPG has a way to find out such information: an Assess check. Without that, the math is left to me. And I can do the math really fast (via the method I showed you), so I'm not too worried about that. If the PCs want to find out AC, DR, HP, attack bonus, etc. of a creature, they only get that if they roll an Assess check. Otherwise, yeah, I'm with you. Again, though, that math works for me, so it's no biggie.


delericho said:


> But if it works for you, that's great. As you say: Play what you like.



And if it doesn't work for you, that's cool, too. Because, yeah. That's how it goes sometimes  As always, play what you like


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## Dannyalcatraz (Jan 20, 2013)

My favorite RPG system has something resembling AC- called Defensive Combat Value (DCV)- _and_ damage reduction in many forms.

So I say both.


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## Obryn (Jan 20, 2013)

Dannyalcatraz said:


> My favorite RPG system has something resembling AC- called Defensive Combat Value (DCV)- _and_ damage reduction in many forms.



If you're talking Powers & Perils, you're talking my language. 

-O


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## dwayne (Dec 7, 2013)

I would say in a modern game DR works very well as a bullet vest or body armor does not work unless it is hit, so you can still suffer impact damage due to even with a vest you can break a rib and have some heavy bruising. Also with the modern d20 it had a defense bonus I always took this to represent your experience in life and verse the things you overcome you learn how to avoid or are just a bit smarted about not getting hit and defense in general. Using the D20 star wars vitality and wound system and armor as dr which makes all weapon damage increase by one step with the massive damage roll (I modified this so the DC is the damage done, makes it very dangerous and gritty, I ran my first game in my darkworld game ,[ a mix of grim, supernatural and angel buffy of a sort,] they split up and two of the PC found the vampires holding the other players sister in game and they just pulled up in front an a PC leaned out the window and yelled at the building cussing the vamps. So the one that was looking out who heard them drive up took aim on the van and when he did this the vamp just shot him with the Remington high powered rifle (3d10) in this and was way over his Mass damage roll so he rolled a save vers damage and failed, taking all hit points and putting him to -1 because the wounds damage was more than his wounds score he almost died as they rushed him to the hospital and will be out of action for at lest a two days as one person is a doctor who has made a lot of chemical substances which do help healing but even with this he still can not even get out of bed for a few days. this worked far better than I had thought until they went back and rammed the van through the front of the warehouse which broke the axle and jammed and bent the side door a few came out through the window and got shot up a bit with the vamps shotguns they exchanged fire and then more of the players came out and the one stated to do a prayer ritual and the other was shooting a flare gun into the shadow areas and on his second round hit one with a flare killing it. the one player who was out first go shot with two shot guns and climbed back into the van to get patched up by the doc.


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## GMMichael (Dec 7, 2013)

Just weighing in quick -

I like both concepts - armor class and damage reduction - so I'm including both in my homebrew (well, internet-brew).

Armor class, or damage avoidance, I treat as a skill.  A character with this skill knows how to dodge, roll with the punches, or shrug off damage.  He doesn't necessarily need armor, which would actually slow him down.

Damage reduction is provided by armor.  Hurting or killing someone wearing armor, but who can't dodge well, is just a matter of time.

In this system, a character has three life-saving options:
1) get really good at avoiding all damage,
2) go ahead and get hit but reduce the damage as much as possible,
3) do both!


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## dwayne (Dec 7, 2013)

DMMike said:


> Just weighing in quick -
> 
> I like both concepts - armor class and damage reduction - so I'm including both in my homebrew (well, internet-brew).
> 
> ...




I can see were your going with this and its along the line of think I had as I just used what was around and tweaked it a bit 

1) get really good at avoiding all damage,

In my version this what class bonus does for the most part as well as your dex bonus

 2) go ahead and get hit but reduce the damage as much as possible,

and this is what armor does and natural DR as well

3) do both!

and you can use both

I have also thought about the Armor bonus and non- proficient bonus and was thinking it was a bit much so looking As I just use ac for DR in game I was thinking of if you are not proficient to allow you to have the DR but apply the armor check penalty to your AC as a penalty. That was you could wear the armor but due to you don't know how to wear it properly or are use to wearing it it cause issues with your movement to defend and dodge attacks.


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## ExploderWizard (Dec 8, 2013)

My preference would be for whichever system served the overall game better. D&D is an abstract game with regard to combat. It does not capture the landing of each blow, each slight movement of the combatants. Static defenses and hit points that partially represent fighting skill serve the overall system intent very well. 

I also enjoy the more simulationist feel of GURPS combat. Here the combat is not abstract. Every swing, block, parry, etc. is handled as it happens. Vitality does not scale with combat ability and armor provides DR. It is a completely different system for a game with a completely different feel. 

I enjoy both combat systems and think they do a good job for the type of game they are a part of.


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## Meatboy (Dec 8, 2013)

I like armor as AC, at least right now . At least as far as dnd is concerned there will always be a to hit roll if you only modify AC that really keeps things simple as you only need to track one number. DR is another system added on top of this its not too bad at the start but start adding enchantments on, plus you need to edit any spell that modifies AC or grants something like DR things start to get grindingly slow. I feel this is a bad thing because the later editions of DnD can get quite bogged down during combat already.


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## Zhaleskra (Dec 8, 2013)

For me, it depends both how it's implemented and how abstract damage and defense are. Part of "not hitting" is the armor itself making the blade, ball, whatever end up going somewhere it wasn't intended to. Generally, I like armor as DR if all damage is "real" and defense is abstract, like agility+dodge+armor+roll. As you can see in that equation, armor is also part of defense. That said, I guess I like armor as armor class when there isn't a defense roll.


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