# Thread: AC: is it worthless?

1. ## AC: is it worthless?

I often hear comments around these parts that AC is "worthless", with the implication that it isn't competitive with monster attack bonuses. Since my personal experience has been the opposite, I'd like to talk this through and work out the math, see how accurate this is.

Let's set up some standards first. PCs are likely to fight a variety of encounters. Sometimes enemies will be monsters, sometimes they'll be NPCs. Sometimes enemies will be magical, sometimes martial, sometimes a mix. Sometimes you'll have one big enemy, sometimes you'll have two or three moderate enemies, and sometimes you'll have a whole bunch of weaker enemies.

It should be obvious that even moderate amounts of AC will help against swarms of weak enemies, limit how much the bigger ones can Power Attack you for, and block some of the iteratives. But we'd want at least some defence against the bigger ones before we'd call any significant investment "worthwhile". As such, I propose the following standards:

Poor AC: solo melee threats of even CR have a 25%-ish wiff rate
Decent AC: solo melee threats of even CR have a 50%-ish wiff rate
Good AC: solo melee threats of even CR have a 75%-ish wiff rate

(Note: let us define "melee threat" as any monster with special qualities or attacks related to melee, or which lacks special qualities or attacks that would let it avoid melee. In other words, we will include both pure melee and "dual-threat" monsters, but not monsters that obviously were never intended to melee. For example, a Balor would be included but a Rakshasa would not.)

Dragons are currently being ignored because they are more highly optimization-sensitive than other monsters, take way more effort to calculate for, and are generally considered unrepresentative of their CR anyway.

Spoiler
ECL 5 - Poor AC: 16 . . Decent AC: 21 . . Good AC: 26
Spoiler
Achaierai (AB +9)
Air Elemental, Large (AB +12)
Animated Object, Huge (AB +9)
Barghest, Greater (AB +13)
Constrictor Snake, Giant (AB +13)
Devil, Bearded (Barbazu) (AB +9)
Dire Lion (AB +13)
Earth Elemental, Large (AB +12)
Fire Elemental, Large (AB +10)
Genie, Djinni (AB +10)
Gibbering Mouther (AB +4)
Hag, Green (AB +13)
Lycanthrope, Werebear (AB +13)
Lycanthrope, Weretiger (AB +11)
Manticore (AB +8)
Monstrous Spider, Huge (AB +9)
Mummy (AB +11)
Nightmare (AB +9)
Ooze, Ochre Jelly (AB +5)
Orca (AB +12)
Phase Spider (AB +7)
Rast (AB +6)
Skeleton, Ettin (AB +10)
Sphinx, Hieracosphinx (AB +13)
Spider Eater (AB +8)
Troll (AB +9)
Water Elemental, Large (AB +10)
Winter Wolf (AB +9)

Excluded: Basilisk, Cloaker, Ravid, Wraith, Dragons

Average: 9.8125

ECL 6 - Poor AC: 17 . . Decent AC: 22 . . Good AC: 27
Spoiler
Baleen Whale (AB +17)
Belker (AB +9)
Bralani (AB +11)
Demon, Babau (AB +12)
Devil, Chain (AB +10)
Digester (AB +11)
Dinosaur, Megaraptor (AB +10)
Ettin (AB +12)
Girallon (AB +12)
Hag, Annis (AB +13)
Lamia (AB +12)
Monstrous Centipede, Gargantuan (AB +11)
Salamander, Average (AB +11)
Shambling Mound (AB +11)
Tendriculos (AB +13)
Wyvern (AB +10)
Xill (AB +7)
Xorn, Average (AB +10)
Zombie, Gray Render (AB +16)

Excluded: Will o' Wisp, Dragons

Average: AB +10.826

ECL 8 - Poor AC: 20 . . Decent AC: 25 . . Good AC: 30
Spoiler
Athach (AB +12)
Behir (AB +15)
Devil, Erinyes (AB +15)
Dinosaur, Tyrannosaurus (AB +20)
Dire Tiger (AB +20)
Genie, Efreeti (AB +15)
Genie, Noble Djinn (AB +15)
Giant, Stone (AB +17)
Gorgon (AB +12)
Gray Render (AB +15)
Lammasu (AB +12)
Mohrg (AB +12)
Monstrous Spider, Gargantuan (AB +15)
Naga, Dark (AB +7)
Octopus, Giant (AB +10)
Shield Guardian (AB +16)
Skeleton, Young Adult Red Dragon (AB +17)
Sphinx, Gynosphinx (AB +11)
Treant (AB +12)
Xorn, Elder (AB +21)

Excluded: Bodak, Destrachan, Arrowhawk Elder, Ogre Mage, Hellwasp Swarm, Greater Shadow, Dragons

(note: this level had way more than its fair share of non-melee. Even the upper levels don't have this many things that can't be expected to target AC at least sometimes. There's a few marginal calls one way or the other here, but the metric is clear - if it has special attacks or qualities tied to melee attack rolls, it's in. If its non-melee special attacks don't function every round, it's in.)

Average: AB +14

ECL 10 - Poor AC: 25 . . Decent AC: 30 . . Good AC: 35
Spoiler
Animated Object, Colossal (AB +25)
Demon, Bebilith (AB +19)
Formian Myrmarch (AB +15)
Giant, Fire (AB +20)
Golem, Clay (AB +14)
Monstrous Scorpion, Gargantuan (AB +21)
Salamander, Noble (AB +23)

Excluded: Rakshasa, Couatl, Guardian Naga, Dragons

Average: AB +19.125

ECL 12 - Poor AC: 27 . . Decent AC: 32 . . Good AC: 37
Spoiler
Frost Worm (AB +21)
Kraken (AB +28)
Leonal (AB +20)
Monstrous Scorpion, Colossal (AB +34)
Ooze, Elder Black Pudding (AB +19)
Purple Worm (AB +25)
Roper (AB +13)

Excluded: Greater Basilisk, Kolyarut, Dragons

Average: AB +21.3333

(note: I had to bundle CR 14-16 monsters together here, because there's only two CR 15's that aren't dragons Unbundling now that there's more levels to see the patterns from.)
ECL 14 - Poor AC: 27 . . Decent AC: 32 . . Good AC: 37
Spoiler

Angel, Astral Deva (AB +21)
Archon, Trumpet (AB +21)
Demon, Nalfeshnee (AB +20)
Werewolf Lord (AB +24)

Excluded: Nightwing, dragons

Average: AB +21.5

ECL 15 - Poor AC: 28 . . Decent AC: 33 . . Good AC: 38
Spoiler
Inevitable, Marut (AB +22)
Mummy Lord (AB +20)

Excluded: Dragons. CR 15 is sparse, yo.

Average: AB +21

ECL 16 - Poor AC: 30 . . Decent AC: 35 . . Good AC: 40
Spoiler
Angel, Planetar (AB +23)
Archon, Hound Hero (AB +25)
Devil, Cornugon (AB +25)

Excluded: Nightwalker, Dragons... and Greater Stone Golem, because it's more than two standard deviations away from the mean and thus unrepresentative. If a Greater Stone Golem swings, it's not going to wiff against your AC. Best just to accept that fact and move on....

Average: AB +24

ECL 17 - Poor AC: 32 . . Decent AC: 37 . . Good AC: 42
Spoiler
Aboleth Mage (AB +18)*
Demon, Marilith (AB +25)
Frost Giant Jarl (AB +30)

Excluded: Formian Queen, Dragons. Aboleth Mage technically qualifies, and its spellcasting is highly anemic for its level (5th level spells when PC mages now have 9th), but it's kind of unrepresentative. As a result, I'm giving it a half weighting.

Average: AB +25.6

ECL 18 - Poor AC: 35 . . Decent AC: 40 . . Good AC: 45
Spoiler

Excluded: Dragons. lawl. Sparse level is sparse.

Average: AB +29

ECL 19 - Poor AC: -- . . Decent AC: -- . . Good AC: --
Spoiler

Excluded: Dragons. And you thought 18 was sparse!

Average: AB --

ECL 20 - Poor AC: 36 . . Decent AC: 41 . . Good AC: 46
Spoiler
Demon, Balor (AB +31)
Devil, Pit Fiend (AB +30)

Excluded: Dragons, and Big T for the same reason as the Greater Stone Golem. He isn't a "melee threat", he's a puzzle monster.

Average: AB +30.5

Personally, I think the numbers here are pretty conclusive. It should be easy for most characters who care about it to get AC into the effective range at lower levels. At lvl 10 there's actually something of a peak, where AB has scaled faster than AC likely has, but even then a committed character can manage. But after that, AB hardly seems to scale at all, and the vast wealth of the higher levels can easily catch your AC back up without leaving you short in other areas.

2. ## Re: AC: is it worthless?

The primary reason why I've personally found AC in general to have diminishing returns beyond around level 7, based on games I've seen and been involved in, is that somewhere around that point more and more encounters deal with Save-or-Suck, Save-or-Lose, Battlefield Control, or Touch AC attacks. While the last is defended by *a form of* AC, most armor, and armor boosters, don't do much for Touch AC, leaving the characters I've dealt with looking at Cover, Concealment, and Miss Chance as necessary, more reliable defenses. It is my experience that a majority, or at least a sizable minority (around 40% or higher), of encounters starting around that point are against enemies that are either NPCs or, at a minimum, have levels of PC classes, even if there exist monsters in the various manuals for the theoretically appropriate CRs.

AC still has its function, but it's simply a layer of protection at that point in the game, and not necessarily the primary layer.

Again, I'm not saying my experience is necessarily typical, I'm merely explaining the experiences I've had which have shaped my conclusions.

3. ## Re: AC: is it worthless?

i wouldn't say that any part of a PC's defense is worthless, they all mesh together to protect the PC. I DM for a group of newbies, and most of my players don't even know what optimization is, so their AC is below what you would define as poor. that being said, they still defend against a decent chunk of melee attacks against them, just by the luck of the dice. but then i have an experienced player playing a toned-down wizard who casts a few defensive buffs on the other PCs, so that adds to their total defenses. what AC doesn't protect against, the stoneskin spell helped resist. i'm sure there are countless other better examples, like blur or something, but that's the one that came up most recently for us last session.

all that having been said, i'm really trying to convince my players to get items for higher AC, or i might give them some as loot, because it's just really low. to them, AC is as far from worthless as it could be, simply because it's so low for them. they just don't seem to know how to boost it.

4. ## Re: AC: is it worthless?

sonofzeal, you're like a megazord of awesome and win.

5. ## Re: AC: is it worthless?

Either you invest a lot in AC, or you invest next to nothing into it. At higher levels, there seems to be no middle ground and armor is only for the enhancements. If monsters buff up or you play against NPCs with PC class levels, then you need a much higher AC for it to be effective.

IIRC, there was a formula that monsters generally should have an AB of CR+13, so that an AC of CR+23 or higher is okay and having an AC of CR+33 is unnecessary, unless you absolutely want to dodge True Strike attacks.

6. ## Re: AC: is it worthless?

There is the big boss argument, and the factor on how much the DM optimizes the monsters. Say level 5 vs VoP huge earth elemental, who has taken martial study twice and martial stance, or been given a level of an initiator, for a high end example.

I think thats one of the scariest monsters there is.

7. ## Re: AC: is it worthless?

Very interesting analysis, and not something I've really thought to delve into. I personally don't buy into the idea that AC is useless, but it can be difficult to keep up. This is more true for some class types than others, of course.

The other issue is: so many monsters and NPCs have abilities that don't require attack rolls at all, just like PCs. These make AC a little less useful than, say, higher saves, at least at first glance.

We also have to look at the costs in gp, feats, and class abilities. Hit point damage is easy to heal, while other conditions (like death from SoDs) can be more tricky, at least requiring higher-level spells.

One last thing that occurs to me is opportunity costs. Getting your AC up by a few points contrasted with miss chance, higher saves, greater offense, etc.

Very cool breakdown.

8. ## Re: AC: is it worthless?

How high of an AC can you get for the price of a cloak of displacement?

Off the top of my head
+2 self crafted mitheral full plate 9k
+2 deflection
+1 nat armor
+1 shield
Which makes it better than the cloak till about level 15 against at level monsters

9. ## Re: AC: is it worthless?

It would also be interesting to see some AC costs vs. WBL comparisons. Assuming a character without any inherent AC boosting class/race features, how much does it cost to remain competitive.

10. ## Re: AC: is it worthless?

AC isn't worthless, there are just usually better things to spend your money on.

At the extreme end of the scale you have to ask "Is it cheaper to buy a Contingent True Resurrection than it is to increase my AC to a point where it will save me money?".

The real problem is that attacks against AC are just about the rarest thing around in higher level play. One of the things that makes pre ToB melee so weak is it's dependence on full attacks and the utter inability to actually get those against even a half competent enemy. Between alternative movement types (flight being the most common), miss chance of one form or another, contingent defenses, and the various other options in high level play; AC is simply the least useful defensive option to spend money on in higher level play.

Unless you dedicate a significant chunk of your wealth to AC (or have other methods of pumping your AC), you aren't going to get it high enough to overcome the AB of an equal level NPC built half competently. Against the stock monsters it's relatively easy to pump your AC high enough to matter but against purpose built enemies it's far more difficult.

That being the case, you are generally far better served by spending your funds dedicated for defense on alternative options.

11. ## Re: AC: is it worthless?

Originally Posted by Emperor Tippy
The real problem is that attacks against AC are just about the rarest thing around in higher level play.
Higher level play is also the rarest kind of play.

12. ## Re: AC: is it worthless?

Originally Posted by Lans
How high of an AC can you get for the price of a cloak of displacement?

Off the top of my head
+2 self crafted mitheral full plate 9k
+2 deflection
+1 nat armor
+1 shield
Which makes it better than the cloak till about level 15 against at level monsters
But the cloak also has other benefits, like negating precision damage and also being effective vs. touch attacks

13. ## Re: AC: is it worthless?

Higher level play is also the rarest kind of play.
It's not that rare.

14. ## Re: AC: is it worthless?

True, but it also costs a whole chunk of money, the ac can be picked up incrementally. You might not have 24k on a cloak, but you might have the 10k to up your deflection bonus from 2 to 3.

15. ## Re: AC: is it worthless?

I think I want to disagree.

CR 5 enemies from the SRD have an average of 56 hp, +10 attack bonus, and 17 AC.
CR 10 enemies have an average 137 hp, +19 bonus, 23 AC
CR 14-16: 213, +27, 29 AC
CR 19-21: 386, +39, 37 AC (and I should point out that it goes from +29 for a Behemoth to +57 for a Tarrasque - lot of variance in there)

I've removed outliers but kept dragons (I can see why you didn't though).

Amusingly, it's actually pretty straightforward like this: the expected average bonus of any monster is twice his CR, give or take. But AC doesn't progress like this.

At ECL 5, you've got 9,000 gp. Assuming you're playing a character that expects to go into melee and take his chances getting hit, you'll be sporting some kind of medium armor or better (let's go with a breastplate, they're cool). Let's assume a third of your WBL goes into armor (weapons cost twice as much for equal enchantment numbers, and there's the rest of your gear - in my experience it's actually been way less). You have 3,000 to spend. That's +1 armor with a ring +1. Your AC is 10 +6 (+1 breastplate) +1 (ring) +3 (dex) +1 (let's say you've got a feat or class ability there) = 21. So far, so good.

At ECL 10, you have 49,000, a 16,000 budget (I'm rounding). The same breastplate is now mithril, +3 with a +1 ring and +1 amulet. Your AC is 10 +8 (+3 breastplate) +1 (ring) +1 (amulet) +5 (dex, yay mithril) +2 (you got another class ability, go you!) = 27. Already a tiny bit behind the curve.

ECL 15, you have 66,000 to spend. 16k go into an animated +1 tower shield and the 50 remaining go to a +5 breastplate, +3 ring and +2 amulet. AC is now 37-ish. Still playing catch-up for such an investment.

ECL 20, you're now king of the hill. With 253k to spend on armor, you can go all out except you're running out of options. A +5 animated tower shield, +5 breastplate, +5 ring, +5 amulet only get you to spend 189k gp, and your AC tops at 45, 46.

At that point, it's all you can do to catch up (unless you have class features or feats that add significant amounts of AC) and you're sinking all your cash in armor - but don't have any left on the side for other enchantments.

So really, it all kind of seems to depend on how many dragons you're likely to see . But more importantly, it all depends on how many spellcasters there are in the mix. Since they own the ECL 10+ game, and since most of them don't care about armor, shield and natural bonuses, your AC becomes irrelevant. I think that's where most of the complaints come from: even if you're still competitive in the AC department, there are a million ways for you to die without anyone ever rolling an attack roll.

16. ## Re: AC: is it worthless?

In general, the likelihood of your character facing an attack against his AC (as opposed to an attack against his saving throws or other defences) is directly proportional to how low-level you are.

At level 1, you're far more likely to be killed by something that attacks your AC than by something that attacks your saves. At level 20 it's the other way round. This is the reason that lots of people look down on AC as a defence.

However, the mistake that the "AC is useless" people tend to make is to forget that lower-level games (levels 1-10) are much more common than higher-level games (levels 11-20).

So yes, if you're playing at level 20, then AC isn't all that important. But the chances of you playing at level 20 are pretty low, not least because level 20 play is so ludicrously unbalanced that most games fall apart long before they ever get that far.

A sidenote that some of you guys might find interesting: When I ran Red Hand Of Doom a few years back, I did a breakdown of the total PC death count once the campaign journal was wrapped up. The campaign ran from level 5 to level 10, and there were a total of 30 PC deaths. (It was one of my higher-lethality games.) For the curious, the causes of death were as follows:

Natural Causes: 1
Being Played As An NPC: 1
Failed Will Saves: 1
Failed Fortitude Saves: 2
Failed Reflex Saves: 9
Direct Attacks: 16

Boosting your AC didn't guarantee your survival in that campaign, but it got you a lot further than boosting your Fort/Will.

17. ## Re: AC: is it worthless?

I remember a while back, Dragon ran a poll on the top causes of PC death, and it turned out to be failed Reflex saves by a pretty significant margin.
I've lost a few to saves, but only one I can recall to a direct attack.

AC is not useless, but it is a specialized area. For the same price as pumping your AC into the 50's, you can get your saves easilly to the same number with a lesser cloak of displacement on top.

Most combats only last 2-3 rounds, and at any level over 4, the thing that ends the combat is likely to be a spell. Most of those spells target a save. If you begin combat invisible, etherial, flying and displaced, your opponent needs at least two magic effects in order to be able to target your AC at all. Probably three, depending on the monster's natural abilities. By level 15, you can be all of those things all day long without significant impact to your WBL.

AC, however, is GOING to eat your WBL. So why take AC, when you can be flying, invisible, displaced and etherial with unbeatable saves instead?

18. ## Re: AC: is it worthless?

AC is much more useful if you can't avoid power attack. Without that ability each of a physical monsters (many) attacks will deal extra damage at LEAST equal to how far below par your AC is.

It can generally be said I feel that if your opponent is making a melee attack against you you have done something very, very stupid, because melee combat, at every level, is too risky to built a career on, but we play D&D so we can take risks and have fun so we still end up in melee combat range.

Overall i'd say AC is not negligible if you ever plan on using melee attacks. Ranged power attack is rare, so if you can stay out of melee AC is not very important over level 8 or so.

19. ## Re: AC: is it worthless?

But the cloak also has other benefits, like negating precision damage and also being effective vs. touch attacks
I've found in my optimisation travels that it seems to be quite easy for higher level characters to negate miss chances completely, while beating a high AC is much harder. You do have to put a lot of resources into getting an unbeatable AC (including Touch AC), but it can be done fairly easily given those resources and there isn't any real way to defeat it.

20. ## Re: AC: is it worthless?

Yeah, AC is kinda all or nothing, you either have the means to have it or not. I can't really see a Wizard being able to spend about the same amount of cash to get Fighter/Rogue-like AC than he would to get some wiff chance due to AC.

But even so, its binary nature makes it not an optimal idea for protection (as in, over other methods).

Simple math, for a character with ECL 10 it's not that easy to get 30 AC (not impossible, but between other magical items that offer unrivaled utility and weapons, I'd say it's not that high on the priority list, unless it's the main damage soaker).

But what does that AC net him? About 50% chance of not being hit by monsters.

Now, if instead he layers his protection with miss chance and whatnot, not only he can get to around the same (if not higher) percentage of not being hit, but it also protects him against other things against which AC is rather useless, such as touch attacks, surprised/sneak attacks and so on.

21. ## Re: AC: is it worthless?

Pumping AC does have its uses. Abjurers have an easy time boosting their ACs into the 40+s using mage armor, shield, alter self, items. Wizards generally have little to no health from their crappy D4s so pumping AC can be hugely life saving because getting hit once with a weapon can be fatal. However, AC does begin to wear out around 15+ level because the saves grow steeper. But, if AC can be boosted using extend/persist spells, why not dump the rest of the gold into items that give bonuses to saves?

22. ## Re: AC: is it worthless?

IMO, AC is extremely useful at very low levels (1-5), and then has diminishing returns.

Going full defense via Combat Expertise probably has saved more low-level characters in my games than anything else -- because it is marginal value that counts: If you are a 5th level PC, and you have a standard AC of 21, then a level-appropriate monster will hit you 50% of the time (using IML's CR x ~2 = Attack ratio finding). Using Combat Expertise to full effect will make your AC 26, and you get hit 25% of the time, i.e. only 1/2th of the time.

At higher levels, getting AC pushed up into the area where Combat Expertise (or any other additional effect that can be paid for) has this effect is much harder, IMO.

I'd also absolutely agree with Saph's experience on PC deaths: In my games, Reflex caused most PC deaths after physical damage. I think one of the reasons is that monsters with Save-or-Die effects are often reserved for special situations, and PCs work hard to defend against these effects, as well (Death Ward), because the thought of losing a character to a single failed roll is so terrifying for most players. Attacks targeting Reflex are much more commonplace, often do not kill on the first hit, but on subsequent attacks.

23. ## Re: AC: is it worthless?

I think a lot of the problems experienced with AC comes from two sources. The first is that AC requires monetary investment, or full spellcasting, to keep up. There is no automatic scaling of AC. Unless you dump a lot of money into it, if you start at AC16, there's a really good chance you'll stay at AC16 until you retire your character. People generally don't want to spend all of their money on passive defenses, or at least not any significant chunk of it. They might be willing to pay out gold for 1 +x item, but 3 or 4 different ones just to keep AC where it should be? Nobody wants to do that. Even defensive characters would rather be paying for other options.

Second, there are some tables that heavily optimize encounters. This optimization tends to push needed AC ranges even higher. There's some guy over on minmax boards who claims less than +30 to hit at level 10, or +50 by level 15, is the DM taking it easy on the players. This drastically increases the AC a character needs to buy, to the point that achieving it would require basically all of their character resources, or be unattainable. It's far easier to just ignore AC entirely in this situation.

Okay I lied, there is a third reason: Attack bonuses vary far too much to be able to reliably gauge what is required to survive. The analysis someone did below takes out a lot of outliers, but the fact is those outliers do exist. Even using stock monsters, if you have 30 AC because the average monster has a +20 to hit, there is a very real possibility of a monster coming along with a +30 to hit, and rendering all your investment in AC completely useless as you get pummeled anyway. Even if rather than the norm, this is something that happens only once or twice a level, it's enough to discourage you from investing in AC because you'll remember that time that despite all your investment, you still got hit on a 2 that time.

The only way this would be fixed is by normalizing the RNG. That means normalizing attack bonuses and defense values of creatures to some degree. That means that a monster with 2-3x more hit dice than CR probably needs to be heavily modified to bring it's BAB in line. It also means monsters with 10-20 more strength/agi than is normal, or attainable by PCs, would also need to be brought in line. It also means that PC AC needs to scale automatically, increasing enough to be relevant against some attacks without any extraordinary investment.

You can have some variation among monster to-hit bonuses, but it should be in the range of about 5 points, not 10 to 20. You can have a range of ACs, but it should be on a similar scale. The best attacker might hit the weakest defense on a 2, but for the most part you should have people somewhere in the middle. Until this is done, there will always be complaints about AC, and people will eschew it in favor of more reliable protections like miss chances.

24. ## Re: AC: is it worthless?

Originally Posted by Malachei
IMO, AC is extremely useful at very low levels (1-5), and then has diminishing returns.

Going full defense via Combat Expertise probably has saved more low-level characters in my games than anything else -- because it is marginal value that counts: If you are a 2nd level PC, and you have a standard AC of 19 (Breastplate, Large Shield, +1 Dex, +1 other), then a level-appropriate monster will hit you 30% of the time (using IML's CR x ~2 = Attack ratio finding). Using Combat Expertise to full effect will make your AC 24, and you get hit 5% of the time, i.e. only 1/6th of the time.
How are you using Combat Expertise for +5 at level 2? It's capped by BAB just like power attack is.

25. ## Re: AC: is it worthless?

Originally Posted by ILM
ECL 20, you're now king of the hill. With 253k to spend on armor, you can go all out except you're running out of options. A +5 animated tower shield, +5 breastplate, +5 ring, +5 amulet only get you to spend 189k gp, and your AC tops at 45, 46.
Mithral Fullplate instead of Breastplate (+3_
Defending Armor Spikes (+1 - +5)
Defending Shield Spikes (+1 - +5)
Dusty Rose Ioun Stone (+1) <- for 5k gp, this is cheaper than upgrading a Ring of Protection from +1 to +2.
Skin of the Defender (+4; stacks with Ammy of NA since it's not an enhancement bonus)

That should be more than enough to keep you golden for quite some time. And that's without dipping outside the SRD. Seriously, I think the lack of education on how to manage AC is behind most of the criticism it gets.

Originally Posted by Acanous
For the same price as pumping your AC into the 50's, you can get your saves easilly to the same number with a lesser cloak of displacement on top.
....how? After Cloak of Resistance and Item of Ability Boost +6, where are you getting more than the occasional pocketchange?

Most combats only last 2-3 rounds, and at any level over 4, the thing that ends the combat is likely to be a spell. Most of those spells target a save. If you begin combat invisible, etherial, flying and displaced, your opponent needs at least two magic effects in order to be able to target your AC at all. Probably three, depending on the monster's natural abilities. By level 15, you can be all of those things all day long without significant impact to your WBL.

AC, however, is GOING to eat your WBL. So why take AC, when you can be flying, invisible, displaced and etherial with unbeatable saves instead?
...we get it. Wizards rule, everyone else drools. Except sometimes people want to play some of the other 71 classes in the game. Every once in a while. Y'know?

Originally Posted by Saph
A sidenote that some of you guys might find interesting: When I ran Red Hand Of Doom a few years back, I did a breakdown of the total PC death count once the campaign journal was wrapped up. The campaign ran from level 5 to level 10, and there were a total of 30 PC deaths. (It was one of my higher-lethality games.) For the curious, the causes of death were as follows:

Natural Causes: 1
Being Played As An NPC: 1
Failed Will Saves: 1
Failed Fortitude Saves: 2
Failed Reflex Saves: 9
Direct Attacks: 16

Boosting your AC didn't guarantee your survival in that campaign, but it got you a lot further than boosting your Fort/Will.
Thank you for that! I remembered seeing something like that, but wasn't sure where. It bears out my own play experience too. A single failed Will or Fort save might be the end of someone's career, but most DMs don't throw around Dominates and Fingers of Death like candy. Almost all low level monsters, and the majority of mid level monsters, are making direct attacks against AC. Even among high-level monsters, melee threats are fairly common, although they'll usually be packing a few SLAs too.

26. ## Re: AC: is it worthless?

Originally Posted by ILM

CR 5 enemies from the SRD have an average of 56 hp, +10 attack bonus, and 17 AC.
CR 10 enemies have an average 137 hp, +19 bonus, 23 AC
CR 14-16: 213, +27, 29 AC
CR 19-21: 386, +39, 37 AC (and I should point out that it goes from +29 for a Behemoth to +57 for a Tarrasque - lot of variance in there)

At ECL 5, you've got 9,000 gp. Assuming you're playing a character that expects to go into melee and take his chances getting hit, you'll be sporting some kind of medium armor or better (let's go with a breastplate, they're cool). Let's assume a third of your WBL goes into armor (weapons cost twice as much for equal enchantment numbers, and there's the rest of your gear - in my experience it's actually been way less). You have 3,000 to spend. That's +1 armor with a ring +1. Your AC is 10 +6 (+1 breastplate) +1 (ring) +3 (dex) +1 (let's say you've got a feat or class ability there) = 21. So far, so good.

At ECL 10, you have 49,000, a 16,000 budget (I'm rounding). The same breastplate is now mithril, +3 with a +1 ring and +1 amulet. Your AC is 10 +8 (+3 breastplate) +1 (ring) +1 (amulet) +5 (dex, yay mithril) +2 (you got another class ability, go you!) = 27. Already a tiny bit behind the curve.

ECL 15, you have 66,000 to spend. 16k go into an animated +1 tower shield and the 50 remaining go to a +5 breastplate, +3 ring and +2 amulet. AC is now 37-ish. Still playing catch-up for such an investment.
I think you're being a little bit unfair here. First off, anyone who would wade into melee expecting to be attacked would try to wear full plate if at all possible. So this increases the AC in their first example by 3. They could also easily use a shield, anything from a +1 tower to a +1 buckler. So this adds in another 2-5 AC, for a *very* competitive ac at level 5. The conclusion that should be reached here is that for roughly half your WBL (it will admittedly cost more than you listed) you can be nigh-unhittable to cr-appropriate monsters.

By level 10 I find it harder to disagree with you (I might go for mithral fullplate, especially if I wanted to optimize strength over dex, but this could admittedly be cost prohibitive). However if you were trying to optimize AC you could easily spend the extra money for an ioun stone of +1 insight bonus. You could also spring for the early animated tower shield or a buckler with improved buckler defense or some such. Let's say you just go with the ioun stone of insight bonus and the +2 buckler -- you've just spend 9000 more (25,000 total) but you've got +3 AC. Enemies are missing you more than 50% of the time. Iterative attacks are missing you 75% of the time or more. You still have enough for a +2 weapon, two +2 stat items, and a cloak of resist +2 at the very least. This isn't even taking into account that by level 10 you probably have some spellcaster friends who could spare spellslots to greater magic vestment your stuff, barkskin you, haste you etc, to significantly increase your AC.

By level 15 your access to AC-increasing spells should be easy as pie. 3rd level pearls of power are cheap for you. Buy your casters some. Magic vestment everything for 15 hours/day to save enchanting that breastplate. Buy them another rod of lesser metamagic extend for 3k so it lasts 30 hours just to be sure. The tower shield could be +5 too that way and you'd still save money overall. Most melee classes would either almost always be hasted (if they had an arcane caster) by this point or have boots of speed. Another +1. You'd *definitely* have the ioun stone by now. +1. I've just created a scenario where your AC is 6 higher than you listed in a fairly similar price range, and this is just assuming you have a cleric in your party using one 3rd level spell slot on you. Other casters could achieve similar or better results. With an AC of 43 the cr-appropriate monsters you listed would need an average of 16 or better to hit you. That's not bad.

I know relying on buffs isn't necessarily appropriate for lots of reasons (the enemies can buff too, dispel magic woes, you may not have allies that will buff you or allies at all, etc). Nevertheless, D&D isn't played in a vacuum -- you generally have allies and they can often cast spells. Smart spellcasters buff their allies. Smarter allies buy items to let those spellcasters buff more often or for longer. I don't think it's that unreasonable to expect it.

27. ## Re: AC: is it worthless?

Originally Posted by Seerow
How are you using Combat Expertise for +5 at level 2? It's capped by BAB just like power attack is.
Thanks. I should not post while tired. I mean level 5, and at the really low levels they are using total defense if they have to (which can be a good trade-off if the action-economy ticks for you).

28. ## Re: AC: is it worthless?

Originally Posted by Malachei
Thanks. I should not post while tired. I mean level 5, and at the really low levels they are using total defense if they have to (which can be a good trade-off if the action-economy ticks for you).
I once handedly won a lvl 3 arena match against a Wilder using Psionic Shot and Empower Power with Wild Surge to deal ridiculous damage in a single shot. I won it by waiting until he got just about ready to alpha-strike me into oblivion, and then taking total defensive (+6 AC, standard action, readied) while dropping prone (+4 AC vs ranged, free action, part of the readied action), behind cover (+4 AC). Halfway through manifesting the power, instead of aiming for 14 touch AC, he was looking at 28 touch AC... and it was too late for him to abort.

I think that was my proudest single action of my gaming career.

29. ## Re: AC: is it worthless?

I see AC just like I see saves and other forms of defense: a rock paper scissors scenario. I also think a DM should throw of mix of those threats at the PCs. If one of my PCs went for a tanking/extreme AC boost Build I wouldn't make him feel worthless by constantly hitting him every battle, be it by spells or very high attack rolls.

I think AC is practical for a lot of characters. Maybe over-rated, but I am skeptical that people would play a character with a lousy 14 AC the whole game, dealing with almost every melee attack hitting after 10th level or so.

30. ## Re: AC: is it worthless?

Originally Posted by Saph
The campaign ran from level 5 to level 10, and there were a total of 30 PC deaths. (It was one of my higher-lethality games.) For the curious, the causes of death were as follows:

Natural Causes: 1
Being Played As An NPC: 1
Failed Will Saves: 1
Failed Fortitude Saves: 2
Failed Reflex Saves: 9
Direct Attacks: 16

Boosting your AC didn't guarantee your survival in that campaign, but it got you a lot further than boosting your Fort/Will.
How exactly did you count these? Consider for example a Crusader (no ranged weapon prof) that fails his reflex save vs. Entangle and then gets shot to death by some archers he can't reach or retaliate against. Would that count as death by damage or death by failed reflex save?

Asking because in the level range we're talking about (5-10) many spells don't kill, but incapacitate the enemy to such extent as to make actually killing them trivial.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•