Behold the Power of AC Optimization! Wait, What?

[dascarletm]

So I constantly hear that going for AC is just a bad idea all around, in regards to defending against attacks.

However, I pulled a little spreadsheet madness and set up a way to calculate the average damage per round of a creature. For my first example I took ze Balor.

Our first punching bag, Joe the Melee Man, most just call him Joe, is fielding Full Plate A Heavy Steel Sheild (may be free floating). He's not super specced towards AC, but he picked up a ring of deflection +2 and an ammy of NA +3. His Armor has a +2 bonus and sheild has a +2. He's got 12 to dex. His AC is 30 (+10 armor, +3NA, +2Def, +4Shield, +1 Dex +10 Base)
I then calculated his average damage per round for the balors full attack.

He takes: 52.65 damage a round.

Sophie the Armored on the other hand is sporting a stylish Mithril Full Plate with nimbleness +5, +5 ring and ammy, and a +5 mithril tower shield. She's pretty nimble and with mods she has +4 dex. She's got 42 Armor.

She takes: 8.75 damage a round.

Now their difference in armor is pretty vast. It ends up getting you roughly 0.75 less damage per attack (for the balor) per point of AC. Which doesn't seem like much, but over multiple attacks...

I don't see this as being horrible.

Some monsters have one big hit on a large +mod, which sucks any way you slice it, but with iterative attacks it seems AC helps.

I also made a table a while back to calculate the statistically most optimal PA amount based on to hit and AC. Higher AC makes you do even less damage with PA.

Also I'm just looking from a attacking you standpoint, spells and such are a whole other issue.

[Callin]

meanwhile with that set up she is also doin only 8.xx a round lol.

Optimizing for armor is fine but its secondary to other things.

[dascarletm]

meanwhile with that set up she is also doin only 8.xx a round lol.

Optimizing for armor is fine but its secondary to other things.

True, but it seems to get the reputation for being pointless, in that it doesn't matter.

[Callin]

Oh I believe AC matters. It matters a good bit at the lower levels and gets less and less love as the levels progress. Because its easier to get +Hit than +AC.

So while you do need to improve your AC as you level it just becomes less primary and more secondary to other things that will keep you alive better.

Of course it also depends on how your DM runs a game and what type of Monsters they throw at ya.

[nedz]

Actually it's reputation is all or nothing.

Either you pull out all of the stops and optimise it as much as you can afford, and it does mainly come down to equipment, or you don't bother. Miss chances, on the other hand, are more predictable and cheaper.

[Callin]

See Mischance to me is even worse than AC. The higher stuff will simply bypass that not a problem. Not worth the cost either.

[Keneth]

The difference is, Joe spent about 35k on his armor, and Sophie spent 171k. Joe spent that huge pile of money on increasing his damage, and ended the fight in 2 rounds, protecting both himself and the party. Sophie on the other hand is little more than an annoyance to the balor and he'll probably just dominate her while he kills the rest of the party or use implosion or telekinesis on her, avoiding armor altogether.

[DeltaEmil]

Against touch attacks, Sophie is hosed. Also, strong and powerful monsters have the tendency to be really big and use grapple attacks (and some of the more horrible ones have improved grab), making Sophie's wonderfully high AC useless.
The balor, a highly intelligent demon, will use its spell-like abilities first anyway and make Sophie insane, dominated, dazed, weakened, or any other horrible status condition. And Sohpie is most likely some lowly melee-combatant with none or practically no relevant spell-casting ability. Unless Sophie is a cleric.

[dascarletm]

SURPRISE Sophie is a cleric, melee damage is of no consequence!:smalltongue:

I see the point, and I was thinking people were saying to dump AC.

[SowZ]

If you don't want to focus on equipment to get the bonus, you have to find ways to get a bonus to AC based on a stat or two and stack the AC bonus from that stat with itself. Find three different ways to add Cha to AC, each with a different type of bonus, and have crazy Cha, for example. You can get insane AC this way but now you are investing levels and LA and such, not just gold.

Dip Battledancer. (Most DMs won't let those two stack.) Divine Shield feat, (shield.) Mystic Wanderer, (sacred.) Risen Martyr, (deflection.) If you go Paladin after that, you could cast Visage of the Greater Diety and Righteous Aura.

A spellgifted Unseelie Fey Lesser Maueluth with base 18 Cha and 15 Dex and 13 Wis, +6 Cha Item, +5 levels, +5 Inherent, +4 Racial, +4 Sacred has 46 Cha. +5 Inherent and +6 Dex Item gives us 30 Dex. +5 Inherent and +6 Item gives us 24 Wis. With +5 Natural AC Amulet, a Monk's Belt, and a +5 Tower Shield, (have it flying so as not to interfere with class abilities and such,) get +1 Luck to AC, insight, (parrying weapon is best for this,) and +1 dodge and we have 117 AC.

We're spending 500K on stat boosting, 50K on our shield, 50K on out Amulet of Nat. AC, and maybe another miscellaneous 50K on other stuff. 150K under WBL.

[Karoht]

The Big Bad "Tanking" Stats and Effects

1-Avoidance:
Things where the damage will be zero if certain conditions are met.
-AC-Attack Roll lower than AC = No damage
-Miss Chance-Separate chance to miss, based on percentile dice. Below threshhold level = miss
-Spell Resist-Caster Level Check lower than SR = No effect, essentially AC for spells.

2-Mitigation
Reduces Damage total directly. Often bipassed by specific effects, or only alters damage from specific causes.
-Damage Reduction
-Elemental Resistances

3-Deference
Damage is not necessarily applied directly, all at once, or all on one target.
-Crusader class feature
-Life Link Oracle Revelation
-Eidolon/Summoner link.
-Interception of effects intended for another

4-Immunity
The effect outright has no effect, or no noteworthy effect.
-Elemental Immunity
-Spell Immunity
-Spell Resistance-See Avoidance
-Anti Magic Sphere or other suppression/nullification area spells.

5-Cover/Blocking
Blocking line of sight or line of effect outright prevents certain effects from being usable, thereby preventing their damage. Cover can and often does also increase other stats and abilities for further avoidance/mitigation. Also usually prevents precision damage (such as Sneak Attack).
-Improved Evasion and similar effects.


Working in concert, they are all awesome. Individually, if I had to pick one of the above? AC is very broadly used. Cover is useful in an astounding array of circumstances. Damage Reduction is extremely common to encounter, and usually covers off a lot of possible incoming damage. At the same point, all three are very easy to bipass in some way. AC is often bipassed by Save or Suck spells which don't interact with AC, or if they do it is a Ranged Touch Attack. Cover is often negated by positioning. Damage Reduction is limited in it's mitigation, and sometimes has a method of bipassing it (IE-Silver VS Werewolves). I think I would still pick AC over the other two, just for how general purpose it is. It's also probably the easiest to stack.

[Douglas]

Because its easier to get +Hit than +AC.
At low and mid op, yes. In high op past the low levels, it switches because there are many many more potential sources of AC than attack bonus and you finally have room to fit more than a few of them into one build.

[Talderas]

True, but it seems to get the reputation for being pointless, in that it doesn't matter.

It's reputation is that it's all or nothing.

The other problem with all or nothing is that you need to invest a lot into that all or nothing at the expense of other things. You end up losing mobility, offense, tricks, or some combination of the three.

The culmination of which is that your character can't be hit but in comparison is of little danger to the opposition, which combined with a lack of options to force foes to pay attention to you ends up making you a liability to the party.

D&D truly operates on the "The best defense is a strong offense" principle so in general a defensive character is worse option than a wizard that prepares Ray of Frost in all his spell slots.

The same principle applies with healing. Healing is not an offensive action (except against undead) and in battle healing is always less efficient than out of battle methods. More often than not, the amount of damage you heal is usually less than what a foe can deal in a single round which makes it a net sum loss.

[Flickerdart]

At low and mid op, yes. In high op past the low levels, it switches because there are many many more potential sources of AC than attack bonus and you finally have room to fit more than a few of them into one build.
In high op past low levels, it's also easy to make attacks that ignore AC entirely, so it's a bit of a wash.

[VeisuItaTyhjyys]

Armor class optimization can be most brutal at low levels, really. By the time a party should be fighting Balors, an optimal AC becomes trivial because the deadliest attacks, spells and SLAs, can ignore armor class entirely. Meanwhile, the high AC that no longer defends one's character comes at an increasingly steep opportunity cost, losing out on items and build choices that help deal damage (for mundanes) or simply end the encounter with a handwave (for casters), meaning that the utility of armor class becomes increasingly marginal as its opportunity cost becomes increasingly crippling.

Now, at lower levels, save-or-lose attacks are less ubiquitous and less inherently lethal, while the damage difference between a fighter who's poured most of her funds into armour and one who's poured most of it into weapons won't be as noticeable. In other words, building a character around the concept of winning a battle of attrition is a lot more viable before one reaches the level where the game pretty much turns into rocket tag.

[Spuddles]

Most miss chance items are circumvented by spells that come standard on most outsiders and NPC spell load outs.

Negating AC as a monster is less common, unless your DM is building for it.

AC isnt really all or nothing. Even a little AC means fewer power attacks and iteratives land. I've found AC to be more discrete than armchair players believe it is.


meanwhile with that set up she is also doin only 8.xx a round lol.

Optimizing for armor is fine but its secondary to other things.

I'm not really seeing the loss of damage output, though. Power attack + deep impact and str as primary stat is all you really need. And if we put that on a cleric chassis, we've got stuff like spikes, righteous might, and girallon's blessing. And magic vestment.


In high op past low levels, it's also easy to make attacks that ignore AC entirely, so it's a bit of a wash.

With triple con to touch AC, I think only wish and surge of fortune let you auto hit. Getting your attack bonus past like 60 or 70 is pretty hard. I saw a build on here that was a dwarf ac build. Plenty decent damage, but a massive armor class. IIRC, it was 82. Not sure much comes close to that with PO, and if you do, you won't have room to power attack.

You can get similar results with cha stacking on a gish instead of a barb, too.

[Carth]

With triple con to touch AC, I think only wish and surge of fortune let you auto hit. Getting your attack bonus past like 60 or 70 is pretty hard. I saw a build on here that was a dwarf ac build. Plenty decent damage, but a massive armor class. IIRC, it was 82. Not sure much comes close to that with PO, and if you do, you won't have room to power attack.

You can get similar results with cha stacking on a gish instead of a barb, too.

I'm gonna go out on a limb and guess Flickerdart was referring to things that don't use attack rolls. You know, things that ignore AC, like he said.

[Eldariel]

The problem with this example is that the Balor is more of a mage than a warrior. Indeed, they're at their most fearsome when just employing their varied spell-likes and since they have infinite uses of most and said spell-likes take standard actions, I wouldn't expect them to attack much outside AoOs.

Being able to negate a mage's physical attack damage isn't all that. But granted, AC isn't useless. However:
- AC tends to cost a lot for mundanes to buff to levels where it's powerful vs. CR appropriate encounters (casters get all the AC they want from spells so the opportunity cost is much lower for them): The gold could be used for mobility, tricks and offense instead.
- AC only defends against a category of attacks, and one that gets less common and less dangerous over levels (depending on the campaign): Like I mentioned earlier, Balor is more of a mage so the relevant statistics are your saves, HP and Touch AC for his spells. Same applies to any mage-type opponent or character focused on combat maneuvers (they target your Touch AC and stats instead of your AC). So your AC is only situationally useful and if you invest ~25% of your wealth to it, you'd probably want more than situational benefit outta it.

[Spuddles]

I'm gonna go out on a limb and guess Flickerdart was referring to things that don't use attack rolls. You know, things that ignore AC, like he said.

Like what? Save or X? Those are atrocious at high levels. Most you can pick up blatant immunity vs; the rest you have high enough saves anyway. Precious few opponents use maw of chaos or unncapped hail of stone.

Having 15 AC at level 20 means a single full attack with PA from just about anything kills you in one or two rounds. Dragons and outsiders being the most fearsome contenders.

[Keneth]

Having 15 AC at level 20 means a single full attack with PA from just about anything kills you in one or two rounds.

Not if you're ON FIRE.

But seriously though, who makes normal attacks at high levels? Every monster and its cockroaches have at-will SLAs and Su abilities at that point. Spending your entire fortune on optimizing AC isn't really gonna get you anywhere. It's gonna work in some cases, but you need to be prepared for all cases, which means investing into other forms of defenses, and AC is only good if you go all out.

[Carth]

Like what? Save or X? Those are atrocious at high levels. Most you can pick up blatant immunity vs; the rest you have high enough saves anyway. Precious few opponents use maw of chaos or unncapped hail of stone.

Having 15 AC at level 20 means a single full attack with PA from just about anything kills you in one or two rounds. Dragons and outsiders being the most fearsome contenders.

I don't really understand why you want to ignore maw of chaos, arguably the best damage spell in the game, in a high op setting. It makes me think you're going to just say any other spell also doesn't count.

[VeisuItaTyhjyys]

Well, sure, one can pick up outright immunity to plenty of Save or X, and one can boost saves, but the more resources one devotes to armor class, the less resources one has left to spend on saves and on those immunities. Hence why people have been bringing up that, while AC is valuable, optimizing AC to any meaningful degree requires too steep an opportunity cost.

[nedz]

AC is just one of a number of defences, but in games where meaningful melee happens it is useful and can be optimised without too much trouble.

In games with a lot of powerful casters melee is almost pointless anyway. We all know that spells beat sharp sticks; it doesn't really matter if the beat stick is offensive or defensive in approach.

[Phelix-Mu]

Just a comment, but as DM, I often purposely make sure that monsters that are giving players good experience are able to hit the pcs more thand 5% of the time. Thus, as DM, I optimize to hit of the monsters. If the DM is doing this (to, you know, not make every encounter a rout in favor of the pcs), then value of AC optimization is decreased.

In general, I would think DMs, instead of continuing to throw monsters that can't hit at the pcs, would either increase the attack threat of the monsters, or go for non-attack options (spells, SLAs, other threats that ignore AC). The game can seem like a bit of an arms race at times, but it's kind of the nature of the thing.

A similar dynamic happens with any optimization vs X. If the character is impervious to X, then X will happen. Some of the time. Expect there to be more and more stuff that doesn't do X, though. Expect Y. Why? Because the game is markedly less fun without challenge, and if the characters steamroll everything because they are untouchable, it's not a challenge. Games focusing on role play are an exception of course, since optimization can be arbitrarily irrelevant in such games.

[Tokuhara]

Honestly, knowing that this is defending AC optimization, I have my own 3c (because I go one step beyond):

In my current game, I'm playing an Arctic Earth Dwarf Crusader 4. I currently have Masterwork Battle Armor, a Heavy steel shield, and a Dwarven Waraxe. Almost every encounter, it's Iron Guard's Glare + Melee maneuver to deal enough damage to "pull aggro" onto me. Then, I delay the damage to mitigate how badly I'm getting the crap kicked out of me.

So far, having the high AC is nice, since it's saved me 3 times from a horrible fate (20 goblins and a boss vs a party of 7 with me pulling aggro, 2 gargoyles vs the same party, and 2 gnolls vs a split party that wound up with me having to single-handedly protect a cleric in cloth armor and a half-ogre fighter). Granted, vs the Gargoyle, I was dropped to -5 on a critical hit, but I took the bugger down with me.

[Urpriest]

Not that I disagree with your point in general, but I do think Balor is a bad example. The usual argument why AC is useless is because monsters HD scales much faster than player HD, so they will usually have much higher attack bonus. Also, most monsters have natural attack routines rather than iteratives. A Balor has HD equal to its CR and about the same Str as an equal level Str-focused character, and it fights primarily using weapons, so it's not really a good example.

A Black Wyrm, for example, has +42 attack. That's before gear, before feats, before anything. And all of the attacks are at either full bonus, or bonus -5.

But Dragons are iconically hard-mode, so let's go find another melee monster.

A Greater Stone Golem has two slams at +42, and is only CR 16. Granted, not a lot of damage on those slams, but still.

There aren't a lot of other melee-based monsters at higher levels, which is the other concern. Until you get down to CR 14 or so, most of the list is casters and special-ability-based monsters, with a few NPC-types thrown in. Most of the time, high AC isn't even going to apply, let alone be useful.

[VeisuItaTyhjyys]

AC is just one of a number of defences, but in games where meaningful melee happens it is useful and can be optimised without too much trouble.

In games with a lot of powerful casters melee is almost pointless anyway. We all know that spells beat sharp sticks; it doesn't really matter if the beat stick is offensive or defensive in approach.

I think more relevant is the fact that even beatstick-to-beatstick AC starts really suffering as levels go up because monsters get bigger and they may as well just start grappling the character to death. Of course, this is exacerbated by the fact that attack scales more quickly than AC, as others have pointed out; a great wyrm blue dragon, to pick a monster largely at random, is missing only five percent of the time against either of the characters in the OP. By the point of buying AC up to the degree that a Dragon has a fifty percent chance to hit (55 AC against the blue dragon, if I still recall my stats properly), the character has sacrificed enough in other areas that the dragon's caster levels will end the PC as quickly as the attacks would have.

[Zubrowka74]

Also, thanks to auto-hit on a natural 20 those monsters that can't hit you still hit you once in every 20 attempts, no matter how high is your AC.

[dascarletm]

Also, thanks to auto-hit on a natural 20 those monsters that can't hit you still hit you once in every 20 attempts, no matter how high is your AC.

True, which means if you are already 19 over their to-hit then having 30 over their to-hit is wasted. But if they need a 10 versus a 15 will decrease their DPR significantly.

[Xerxus]

AC is good in some situations, useful in some and useless in some. At low level it's amazing, above level 10 you will need other defenses. Still good to have though. I'm playing in a Pathfinder game as a dwarven crusader cleric, casting compel hostility with ~30 AC at level 5. It's definitely useful.

[Spuddles]

Not that I disagree with your point in general, but I do think Balor is a bad example. The usual argument why AC is useless is because monsters HD scales much faster than player HD, so they will usually have much higher attack bonus. Also, most monsters have natural attack routines rather than iteratives. A Balor has HD equal to its CR and about the same Str as an equal level Str-focused character, and it fights primarily using weapons, so it's not really a good example.

A Black Wyrm, for example, has +42 attack. That's before gear, before feats, before anything. And all of the attacks are at either full bonus, or bonus -5.

But Dragons are iconically hard-mode, so let's go find another melee monster.

A Greater Stone Golem has two slams at +42, and is only CR 16. Granted, not a lot of damage on those slams, but still.

There aren't a lot of other melee-based monsters at higher levels, which is the other concern. Until you get down to CR 14 or so, most of the list is casters and special-ability-based monsters, with a few NPC-types thrown in. Most of the time, high AC isn't even going to apply, let alone be useful.

When the dragon realizes you have 15 AC, power attack is going to double or maybe even triple the amount of damage you take.

30 AC will reduce your damage by around 50 damage a round and be a minimal investment. Of course pick up a cloak or ring of true seeing sees through it lol, but neglecting AC is asking to get splattered by the first intelligently played monster with power attack.

Sure there will be some monsters that can power through your AC- that's kind of their schtick. But to let every monster tentacle your vulnerable bits? I question how much you're really getting for that sacrifice.

[nedz]

I think more relevant is the fact that even beatstick-to-beatstick AC starts really suffering as levels go up because monsters get bigger and they may as well just start grappling the character to death. Of course, this is exacerbated by the fact that attack scales more quickly than AC, as others have pointed out; a great wyrm blue dragon, to pick a monster largely at random, is missing only five percent of the time against either of the characters in the OP. By the point of buying AC up to the degree that a Dragon has a fifty percent chance to hit (55 AC against the blue dragon, if I still recall my stats properly), the character has sacrificed enough in other areas that the dragon's caster levels will end the PC as quickly as the attacks would have.

At level 15 casters are throwing level 7 and 8 spells around which should be more of a concern to the Great Wyrm mentioned above. As has been established: AC, as well as melee in general, is increasingly marginal. Up until about level 15 though, which is a large part of most character's careers, AC is very useful. Basing this argument upon only what happens at high level distorts the debate.

[VeisuItaTyhjyys]

At level 15 casters are throwing level 7 and 8 spells around which should be more of a concern to the Great Wyrm mentioned above. As has been established: AC, as well as melee in general, is increasingly marginal. Up until about level 15 though, which is a large part of most character's careers, AC is very useful. Basing this argument upon only what happens at high level distorts the debate.

I think not having an avatar sometimes leads to my posts in a thread not being as easily connected to one another; my first post in this thread was that AC optimization was a very viable (I think the word I used was "brutal") at lower levels, but its utility decreases at higher levels. In the post you quoted, I just happened to be defending the latter argument, since the claim that AC is less meaningful at higher levels was the one with which others took issue. Sorry for the confusion, though, I agree that AC is incredibly useful at lower levels and that the debate should not ignore that fact. While I'm not sure if I agree it stays particularly useful all the way to level fifteen, that's just splitting hairs.


When the dragon realizes you have 15 AC, power attack is going to double or maybe even triple the amount of damage you take.

30 AC will reduce your damage by around 50 damage a round and be a minimal investment. Of course pick up a cloak or ring of true seeing sees through it lol, but neglecting AC is asking to get splattered by the first intelligently played monster with power attack.

Sure there will be some monsters that can power through your AC- that's kind of their schtick. But to let every monster tentacle your vulnerable bits? I question how much you're really getting for that sacrifice.

I think the difference here might be in how people are using "optimized." I wouldn't say getting an armor class of thirty at twentieth level requires "AC optimization," at all; as you say, it's a minimal investment. I don't think the thesis of the argument is that "AC should be completely and totally neglected," so much as it is that there is little point, at least at high levels, in devoting a great deal of one's resources to armor class. In other words, at high there are rapidly diminishing returns to investments in armor class once one passes a pretty minimal threshold.

[dascarletm]

Yes, I feel like my title was a bit misleading...