Armor as DR

[frogglesmash]

I like the idea of using class AC bonuses and having armor provide DR instead, but I'm not sure how to convert the armor bonuses to DR. My first instinct was to do it at a 1-1 ratio, but that seems like it might result in DR values that are to low to be worth keeping track of.

[Khedrac]

I like the idea of using class AC bonuses and having armor provide DR instead, but I'm not sure how to convert the armor bonuses to DR. My first instinct was to do it at a 1-1 ratio, but that seems like it might result in DR values that are to low to be worth keeping track of.

Unearthed Arcara contains suggeststions for this, and though not part of the SRD they are open source so most of the SRD websites include it. For example this one (http://dndsrd.net/unearthedDefence.html), just scroll down to "Armor as damage reduction".

[LibraryOgre]

I'd personally go with 1-1 for armor bonus, and enhancement bonuses thereof, but I think you're more likely to run into armor bonuses too HIGH to be beatable... consider fighting a dragon, where they might be rocking 17 points of natural armor (adult White Dragon, which is CR 10, on top of anything else they have... if they also have Mage Armor and Shield spells going, it's boosted to 25, which makes them nigh-invulnerable.

If you go with this, I'd consider a couple extra rules... like bonuses to damage for accurate but non-critical strikes, and methods of defeating armor. In the past, I've suggested that criticals bypass armor at the cost of 1 level of multiplier... so a long sword could do 2d8+2(bonuses), or could do 1d8+bonuses and ignore armor on a critical..

And, as always, I'll pimp Hackmaster (http://www.kenzerco.com/hackmaster/), which has armor-as-DR as a default. It avoids some of these problems by having weapons have higher, and theoretically uncapped, damage, and most spells ignoring it completely.

[Crichton]

I'd personally go with 1-1 for armor bonus, and enhancement bonuses thereof, but I think you're more likely to run into armor bonuses too HIGH to be beatable... consider fighting a dragon, where they might be rocking 17 points of natural armor (adult White Dragon, which is CR 10, on top of anything else they have... if they also have Mage Armor and Shield spells going, it's boosted to 25, which makes them nigh-invulnerable.

If you go with this, I'd consider a couple extra rules... like bonuses to damage for accurate but non-critical strikes, and methods of defeating armor. In the past, I've suggested that criticals bypass armor at the cost of 1 level of multiplier... so a long sword could do 2d8+2(bonuses), or could do 1d8+bonuses and ignore armor on a critical..

And, as always, I'll pimp Hackmaster (http://www.kenzerco.com/hackmaster/), which has armor-as-DR as a default. It avoids some of these problems by having weapons have higher, and theoretically uncapped, damage, and most spells ignoring it completely.

I think I'd go with bonuses from actual armor as DR, but not all 'armor bonuses.'

I'd venture that's what the OP had in mind, and not things like natural armor and spells, etc. As you say, with those added in, the DR would get too high. With just actual armor adding DR, I don't think you'll have that problem at all.

[Hunter Noventa]

I think I'd go with bonuses from actual armor as DR, but not all 'armor bonuses.'

I'd venture that's what the OP had in mind, and not things like natural armor and spells, etc. As you say, with those added in, the DR would get too high. With just actual armor adding DR, I don't think you'll have that problem at all.

I'd agree, only actual armor should be adding to DR. after all, a lot of things with natural armor already have DR. Though i'd personally keep the shield bonus as one to AC, since the entire purpose of a shield is to deflect and intercept blows.

[Calthropstu]

If you go 1-1, it seems like like 2 1st lvl fighters in heavy armor would fight for eternity.

[sleepyphoenixx]

I like the idea of using class AC bonuses and having armor provide DR instead, but I'm not sure how to convert the armor bonuses to DR. My first instinct was to do it at a 1-1 ratio, but that seems like it might result in DR values that are to low to be worth keeping track of.
There is no such thing as DR to low to keep track of. Even DR 1/- is worthwhile against most enemies. Not worth spending huge resources on, but worth tracking if you're basically getting it for free.

The problem with it is that it'll make combat favor THF/few big hits over TWF/archery/multiple small hits even more than the system already does.
DR X/- is rough on rogues and archers even in small amounts while power-attacking greatsword users barely notice it, especially if it comes with lower AC so they can just power attack for more to compensate.

[Fouredged Sword]

Or track dr on a per round basis.

[CharonsHelper]

I do like the feel of armor as DR (put it in my own system) but I REALLY don't think that you should try a conversion in D&D. Too much of the game's assumptions are all based on the idea of armor=DR.

If you just have 1-1 AC to DR conversion then Power Attack will be the only way to actually hurt anything with significant armor, and it will deal far more than before. Every other combat style will be terrible.

There are other systems that use armor as DR, and if you really want to play with it I'd suggest picking up one of them rather than trying to force D&D's square peg into that round hole.

[Crake]

I believe the UA variant does half armor bonus, rounded down, not including enhancement bonuses. The DR amount is then subtracted off the AC bonus from the armor, so all armor of any given type always provides the same amount of DR. For natural armor, it's the same, but I believe it's 1/5, not 1/2, so a natural armor bonus of +5 would become +4, and give DR1/-.

I actually run armor as DR with class defense, and as a personal houserule, I make it so that the armor AC bonus isn't reduced, and the half AC bonus as DR includes the enhancement bonus, so a set of +4 fullplate would give DR 6/-, while providing it's full +12 bonus to AC. As an added incentive for people to actually wear armor, I make the class defense bonus lost while flat footed, or otherwise normally denied dexterity, my reasoning being that class defense is a learned defensive initiative, if you aren't aware of the attack, you can't actively evade it. Following this logic, uncanny dodge is supposed to be primal instinct, or just sheer luck, and as such, characters with uncanny dodge will still lose class defense while flat footed or vs an invisible attacker, so wearing armor in those circumstances will help defend against the attack. Of course, if you get hit by a flat footed touch attack, you're still screwed unfortunately. No armor AC, no class defense AC, and no armor DR. Yay for firearms ambush!

[Florian]

I like the idea of using class AC bonuses and having armor provide DR instead, but I'm not sure how to convert the armor bonuses to DR. My first instinct was to do it at a 1-1 ratio, but that seems like it might result in DR values that are to low to be worth keeping track of.

So basically a radical rebuild of d20?

Then you're starting at the wrong end, meaning you should first try to figure out how the average to hit and damage values should develop along the levels/HD, then you get a rough idea of what DR value is needed to survive those changes, as class-based AC scales even slower than BAB. So if you work with a base assumption of, say, 1d8+2*level as base formula, you'll find that a static conversion of AC to DR will make someone in Full Plate nigh invulnerable at level 1, mincemeat at level 10, and so on.

Also look at the issue of an uncapped Power Attack: With BAB out-scaling AC pretty fast, a good THW build will plough through any kind of DR with ease.

[Calthropstu]

So basically a radical rebuild of d20?

Then you're starting at the wrong end, meaning you should first try to figure out how the average to hit and damage values should develop along the levels/HD, then you get a rough idea of what DR value is needed to survive those changes, as class-based AC scales even slower than BAB. So if you work with a base assumption of, say, 1d8+2*level as base formula, you'll find that a static conversion of AC to DR will make someone in Full Plate nigh invulnerable at level 1, mincemeat at level 10, and so on.

Also look at the issue of an uncapped Power Attack: With BAB out-scaling AC pretty fast, a good THW build will plough through any kind of DR with ease.

Ya know, I have always liked the idea of taking all the d20 abilities, figuring out a point value for everything, and seeing what would happen if you gave characters a number of points to spend to build their own classes.

[Fouredged Sword]

Ya know, I have always liked the idea of taking all the d20 abilities, figuring out a point value for everything, and seeing what would happen if you gave characters a number of points to spend to build their own classes.

Mutants and masterminds with the fantasy addon book. It works okish, but you have to be very involved in character creation to avoid broken silliness.

[Aimeryan]

I've not tried this, however, here is how I would like to try an Armour variant:

Armour (natural and/or manufactured) also gives DR of some value (possibly equal to the AC they provide). When you roll for attack:

If less than Touch AC, you miss as per normal.
If less than total AC but more than Touch AC , you hit but the Armour DR is in play (essentially, you hit the Armour).
If greater than total AC, you hit and bypass the Armour DR (joints, eye slits, legs, whatever).
Confirmed Crits automatically bypass Armour DR.


This should allow non-2H builds to still function well; they'll probably want to boost their Attack Roll, aim for Crits, and/or cause the opponent to be Flatfooted.

2H-PA builds also have the interesting choice of whether to add more PA at the risk of now hitting Armour DR or to keep the PA low. Probably dependent on the total AC and the Armour DR the enemy has.

[Jhaosmire]

Wow, Aimeryan has a cool system I may have to try out.

I play Pathfinder, and in the Ultimate Combat there is an A.C. Variant for Damage Reduction. Essentially, your A.C. bonus becomes DR, but only for Armor bonuses and Natural Armor bonuses. Creatures of a larger size bypass this DR, as do Adamantine weapons. I've been running the variant for a few months now and I like how it works. I do find Power Attack to be more useful than ever, as are weapon buffs (Flaming, Frost, Shock, etc.). Also, anything that uses Touch A.C. bypasses the DR, so there are cool precision attacks that find ways through.

Bonus to this, I find low level characters tend to survive longer (no more one hit KO's). Downside, battles can run a bit longer.

[Jack_Simth]

If you go 1-1, it seems like like 2 1st lvl fighters in heavy armor would fight for eternity.

Not for eternity. Full Plate, turned all into DR, is only DR 8. A standard greatsword averages 7 before str, sure, but will regularly hit 9 or 10.

There are Armor as DR rules (http://www.d20srd.org/srd/variant/adventuring/armorAsDamageReduction.htm) semi-officially, which do 1-1, but don't do it to all of the armor.

However: It gives the two-handed types another leg up over other types of melee characters. Power attack for a one-handed weapon is 1 for 1. Power attack for a two-handed weapon is 2 for 1. Both by default - there's items, feats, class features, and so on that improve that. So when you subtract AC from opponents, and give them DR of the same amount to compenstate... the two-handed attacker with Power Attack hits harder overall. The sword-and-board or two-weapon fighter, on the other hand, uses Power Attack and stays exactly where they are.

This is not necessarily a bad thing, but it does shift relative balance, so it's something to be aware of.


I've not tried this, however, here is how I would like to try an Armour variant:

Armour (natural and/or manufactured) also gives DR of some value (possibly equal to the AC they provide). When you roll for attack:

If less than Touch AC, you miss as per normal.
If less than total AC but more than Touch AC , you hit but the Armour DR is in play (essentially, you hit the Armour).
If greater than total AC, you hit and bypass the Armour DR (joints, eye slits, legs, whatever).
Confirmed Crits automatically bypass Armour DR.


This should allow non-2H builds to still function well; they'll probably want to boost their Attack Roll, aim for Crits, and/or cause the opponent to be Flatfooted.

2H-PA builds also have the interesting choice of whether to add more PA at the risk of now hitting Armour DR or to keep the PA low. Probably dependent on the total AC and the Armour DR the enemy has.
My analysis at 1 to 1 on the DR vs. AC:
1) Boosts all forms of mundane attack (the window of "hits armor DR" was previously "missed completely" so they're hurting things more often). Identically penalizes AC-based defense against mundane attacks (the window of "hits armor DR" was previously "missed completely" so they're getting hurt more often) as two sides of the same coin.
2) Energy damage riders are more useful (DR does not apply to energy damage, so the "flaming" portion of that +1 flaming sword burns opponents significantly more often).
3) Does not change the relative priorities of Attack Bonus vs. Damage Bonus for non-two-handed attackers (other than energy bonuses as noted in 2) except perhaps for lower AC opponents (with which you're power attacking for full anyway).
4) Makes two handers full power attack all the time.
As an example: 10th level Fighter, hitting a critter with AC 20 (touch 10), 10 points of Armor DR.
Suppose the Fighter has a +6 Str bonus, a +4 Greatsword and +10 BAB.
If he doesn't power attack, he's attacking at +20/+15 for 2d6+13. He misses on nat-1 on his first attack, and hits armor on a 2-4 (15%) on his iterative. That 2d6+13 hits 95% + 80%, and is reduced to 2d6+3 15% of the time. Average? 20*1.75 + 10*0.15 = 36.5 damage per full attack.
If he full power attacks, he's attacking at +10/+5 for 2d6+33. He hits armor on a 2-9 on his primary, hits armor on a 5-14 on his iterative. So that's 2d6+33 55%+30%, 2d6+23 40%+50%. Average? 61. Not quite twice as much, but close enough that he's never going to back down off of full power attack.

[Calthropstu]

Not for eternity. Full Plate, turned all into DR, is only DR 8. A standard greatsword averages 7 before str, sure, but will regularly hit 9 or 10.

There are Armor as DR rules (http://www.d20srd.org/srd/variant/adventuring/armorAsDamageReduction.htm) semi-officially, which do 1-1, but don't do it to all of the armor.

However: It gives the two-handed types another leg up over other types of melee characters. Power attack for a one-handed weapon is 1 for 1. Power attack for a two-handed weapon is 2 for 1. Both by default - there's items, feats, class features, and so on that improve that. So when you subtract AC from opponents, and give them DR of the same amount to compenstate... the two-handed attacker with Power Attack hits harder overall. The sword-and-board or two-weapon fighter, on the other hand, uses Power Attack and stays exactly where they are.

This is not necessarily a bad thing, but it does shift relative balance, so it's something to be aware of.


My analysis at 1 to 1 on the DR vs. AC:
1) Boosts all forms of mundane attack (the window of "hits armor DR" was previously "missed completely" so they're hurting things more often). Identically penalizes AC-based defense against mundane attacks (the window of "hits armor DR" was previously "missed completely" so they're getting hurt more often) as two sides of the same coin.
2) Energy damage riders are more useful (DR does not apply to energy damage, so the "flaming" portion of that +1 flaming sword burns opponents significantly more often).
3) Does not change the relative priorities of Attack Bonus vs. Damage Bonus for non-two-handed attackers (other than energy bonuses as noted in 2) except perhaps for lower AC opponents (with which you're power attacking for full anyway).
4) Makes two handers full power attack all the time.
As an example: 10th level Fighter, hitting a critter with AC 20 (touch 10), 10 points of Armor DR.
Suppose the Fighter has a +6 Str bonus, a +4 Greatsword and +10 BAB.
If he doesn't power attack, he's attacking at +20/+15 for 2d6+13. He misses on nat-1 on his first attack, and hits armor on a 2-4 (15%) on his iterative. That 2d6+13 hits 95% + 80%, and is reduced to 2d6+3 15% of the time. Average? 20*1.75 + 10*0.15 = 36.5 damage per full attack.
If he full power attacks, he's attacking at +10/+5 for 2d6+33. He hits armor on a 2-9 on his primary, hits armor on a 5-14 on his iterative. So that's 2d6+33 55%+30%, 2d6+23 40%+50%. Average? 61. Not quite twice as much, but close enough that he's never going to back down off of full power attack.

Ok, if they wield great swords, they can damage each other very slowly.

But if they wield short swords and shields...

[Morphic tide]

My own idea for Armor as DR is to have it be that you reduce the damage of non-Touch attacks by a multiple of how much below the full AC your attack was, with total lack of damage being only from not surpassing the Touch AC.

For example, if you get an overall attack roll of 18 and the enemy has 21 AC, you attack does 3X less damage, where X is the multiple chosen. So if X is 2, the attack deals 4 less damage. This generally increases lethality, as absolutely massive armor ratings can be gotten through by sufficiently massive damage. Which Martial characters are generally very good at.

[Aimeryan]

4) Makes two handers full power attack all the time.

As an example: 10th level Fighter, hitting a critter with AC 20 (touch 10), 10 points of Armor DR.
Suppose the Fighter has a +6 Str bonus, a +4 Greatsword and +10 BAB.

If he doesn't power attack, he's attacking at +20/+15 for 2d6+13. He misses on nat-1 on his first attack, and hits armor on a 2-4 (15%) on his iterative. That 2d6+13 hits 95% + 80%, and is reduced to 2d6+3 15% of the time. Average? 20*1.75 + 10*0.15 = 36.5 damage per full attack.

If he full power attacks, he's attacking at +10/+5 for 2d6+33. He hits armor on a 2-9 on his primary, hits armor on a 5-14 on his iterative. So that's 2d6+33 55%+30%, 2d6+23 40%+50%. Average? 61. Not quite twice as much, but close enough that he's never going to back down off of full power attack.

Thank for the analysis.

You are right; partial hits using DR hurts PA less than it does normal hits, so we increase the value of PA over not using PA (unless bypassing). My original concern was making the system not be unfavourable to non-2H, which I did with the ability to bypass - I didn't really think about balancing in regards to 2H non-PA vs 2H PA. To some extent this is a losing battle anyway (Shock Trooper...), but you are still right.


It might require something like a very high DR that can be removed by being hit (at a 1:1 ratio) - call it Ablative Damage Reduction (ADR). In essence, it would mean hitting the "Armour AC" would be effectively a miss until the ADR was depleted. It would sort of be a separate hit point reserve that only applied when the Armour AC was hit.

How it was restored would probably be key - maybe just at rest periods it can be maintained, or perhaps require someone with Craft(Armour) to put back in shape. [Wands of] Repair spells would probably also make a play. The advantage to this system is that non-2H characters who focus on bypassing the Armour rather than plowing through it would be buffed in comparison.

If we say ADR is ten times the Armour AC, then the above example could be a creature with Touch AC 10, 10 Armour AC (total of 20 AC), ADR 100. The average HP of a CR10 creature would be about 130.

A Power Attack that hit the Armour AC would effectively be a miss until that 100 ADR was removed. Bearing in mind that these attacks would have been full misses before hand, and once the ADR is gone the Power Attacker now has a much greater effectiveness than it would have otherwise (it just has to beat Touch AC of 10 now).


Numbers probably need twiddling with, but that would be the jist of it. It might be worth it to increase the Armour AC by some multiplier (and lower the ADR multiplier appropriately) - dunno.


Edit: Hmm, am I just making armour function something like Shardplate now? ...I'm fine with that.

[Florian]

Ya know, I have always liked the idea of taking all the d20 abilities, figuring out a point value for everything, and seeing what would happen if you gave characters a number of points to spend to build their own classes.

I guess you´d end up with something similar to Starfinder, at least when you want to keep it as a level-based system, meaning a more rigid "outer" class structure, encompassing a very mod-able "inner" structure.

[Jack_Simth]

But if they wield short swords and shields...Still just "very very slowly" rather than "for eternity". Shortswords crit, after all, and you'll be confirming a lot more crits if you don't need to worry about AC meaningfully. You'll be critting 5% of the time, and on a crit with a shortsword you're dealing... 2d6 plus twice Str. That exceeds 10 without much hassle.