concealment vs AC which is better and why?

[Masakan]

Basically what it says above, I hear people saying that concealment is better later game than ac but is it really and if so what are some of the best ways to get it?

[Pinkie Pyro]

25 AC: enemy needs +15 to hit to hit 50% of the time

50% concealment miss chance: enemy misses 50% of the time, even with +infinity to hit

concealment is better, because it's harder to counter.

[sleepyphoenixx]

On the other hand quite a few enemies at higher levels ignore concealment, so you want at least enough AC to avoid being autohit if you expect to spend any time in melee at all (or other layered defenses, if you're a spellcaster).

[eggynack]

On the other hand quite a few enemies at higher levels ignore concealment, so you want at least enough AC to avoid being autohit if you expect to spend any time in melee at all (or other layered defenses, if you're a spellcaster).
On the other other hand, quite a few enemies, particularly ones using (ranged) touch attacks, ignore most AC boosts, and are still blocked by concealment. In any case, I think that the general assertion is less that concealment is superior, but that miss chance in general is superior, even if both may be accurate. Something like blink or mirror image will block an even wider range of attacks. That, beyond its somewhat all or nothing nature (though power attack mitigates that somewhat (and shock trooper un-mitigates it)), is really the issue with AC.

[Snowbluff]

I say use both. Depending on your build, you can get high AC very easily. Then you add concealment on top of that.

The easiest concealment is the Minor Cloak of Displacement for 20. After that is the Ring of Blink.

[sleepyphoenixx]

I'm not saying you shouldn't get concealment. I just think you should also get something that isn't defeated by True Seeing (which quite a few mid-high level enemies have permanent). What that something is depends on your build and available resources.

If you invest in AC at least make it touch AC. If you cast spells, memorize a copy of Friendly Fire. Get some immediate action teleports.

Anything is better than facing something with constant True Seeing and only having AC 10 and nothing else because you depended on Displacement.

[Zaydos]

It depends upon expense.

You can get 20% concealment with an armor enhancement costing a +3 equivalent bonus, this is cheap if you have otherwise cheap armor, but if you want to use your armor to get immunity to death effects then it gets pretty expensive. Of course there's a +1 weapon enhancement which can, but I think that's 3.0. A cloak can give 20% continuously for 24k GP or 50% for 15 rounds for 50k.

AC's cost varies by level. 130k can give you +16 before armor bonus, and you can shave off 16k if you can find a Lv 20 cleric willing to cast Magic Vestment on you for a Lv 3 pearl of power. 178k gives you 37 AC, 35 if you're a raging barbarian, 37 for 142k if you are a whirling frenzy barbarian, (and you can get higher) which gives you a 30-40% miss chance from a pit fiend*, 25-95% from a balor*. Dragons get around your AC, though, with +42 to hit on a black wyrm and +36 to hit on an old red, but both are likely to have Power Attack so your AC ends up being virtual DR.

*Note all of the above also have Power Attack meaning even AC that isn't "useful" ends up equaling DR.

Of these creatures only Balor naturally ignores blur effects (the cloak and the armor), although a dragon might but a dragon has options to ignore armor (Wraithstrike) and if the dragon is built to get around your defenses they will.

Armor gets better against mooks (lower attack bonus) but worst against boss-type foes. Even with Displacement effects you want to invest in armor to at least some extent because of True Seeing, Blindsight (a bigger deal actually as it's more common), and Power Attack.

So get blurring, but don't completely neglect AC.

[Red Fel]

First off, both are valuable, but miss chance is more valuable. Why? Because AC does not scale well with level. At higher levels, if an enemy can hit, chances are they will, which means that there is a threshold above which more AC is a waste. Further, there are ways to bypass AC, either by bypassing dodge AC (flat-footed), or going after touch AC, or any number of other methods. By contrast, concealment is a flat miss chance on top of your AC; it's a chance that they'll simply not connect. There are ways to augment BAB to overcome AC; but absent things that specifically pierce concealment, there is no way to increase your "roll to not miss".

Now, how to get concealment? I'll quote the Lists of Necessary Magic Items (http://www.giantitp.com/forums/showthread.php?187851-3-5-Lists-of-Necessary-Magic-Items) on that one:
Miss chances

Why you need it: Some things you fight have attack bonuses that are too high to be effectively mitigated by AC. Miss chances are flat percentage rolls, and care not how good your opponent is. In addition, miss chances resulting from Concealment mean you can not be Sneak Attacked. Beware, though - relying on miss chances alone to keep you alive means you'll be toast if your opponent has a way of countering them (usually True Seeing, see above).
Cheap:

Shadowy Diadem (DMagic). 4400GP, head slot. Grants concealment for one minute as a swift action, and immunity to energy drain to boot. It doesn't like being caught in high level light spells, but that's not exactly an everyday occurrence.
Smoking weapon enhancement (LoD). +1 weapon enhancement cost. This 3.0 enhancement grants you concealment, with some limitations. Usually considered woefully underpriced.
Shadow Sibling (MoE). 8000GP, symbiont. 50% concealment as an immediate action, constitution modifier times per day. It's as awesome as it sounds, only problem is that it requires sharing your body with some kind of usually-lawful-evil incorporeal aberration thing. May not be available at the local Magic Mart.
Shadow Cloak (DotU). 5500GP, shoulders slot. Grants concealment for 1 round as an immediate action three times per day, along with (good) secondary benefits.
Torc of Displacement (MIC). 2000GP, throat slot. As an immediate action, spend charges to gain varying degrees of concealment for one round.
Blurring armor enhancement (MIC). +1 armor enhancement cost. Three times per day, blur effect (as the spell) for 5 rounds. Swift action activation.
Displacement armor enhancement (MIC). +1 armor enhancement. Once per day, displacement effect (as the spell) for 5 rounds. Swift action activation.
Mithralmist Shirt (MIC). 3400GP, body slot. Gain concealment as a swift action seven times per day, but it is due to a cloud that doesn't follow you if you move.
Eversmoking Bottle (http://www.d20srd.org/srd/magicItems/wondrousItems.htm#eversmokingBottle) (DMG). 5400GP, slotless. Creates a huge cloud of nasty fog without daily limits. This hampers vision (creates total concealment) for everyone involved, but the clever player can work around that.

Standard:

Minor Cloak of Displacement (http://www.d20srd.org/srd/magicItems/wondrousItems.htm#cloakofDisplacementMinor) (DMG). 24000GP, shoulders slot. Continuous 20% miss chance, thank you, come again.
Ring of Blinking (DMG). 27000GP, ring slot. Blinking at will, which is handy for more reasons than the (rather involved) miss chance it grants. An often-overlooked problem with this ring is that being at will is not the same as being continuous - you're going to be spending one standard action out of seven reactivating your Blink if you want it on all the time.
Greater Blurring armor enhancement (MIC). +3 total armor enhancement cost. Blur effect (as the spell) for 10 minutes per activation, and there is no limit on the number of activations per day. The same "problem" as the Ring of Blinking has in not being truly continuous, but with a duration this long, I can't imagine it becoming an issue. If you don't have any other enhancements on your armor, this is cheaper than the minor cloak of displacement.
Gleaming (http://www.d20srd.org/srd/psionic/items/armorAndShields.htm#gleaming) armor enhancement (XPH). +3 armor enhancement cost. Continuous concealment. Very similar to Greater Blurring (above), but can not be bought in steps, and does crazy flashes, which a DM might rule to interfere with your hide checks.
Burnoose of Moonless Nights (Sand). 33000GP, body slot?. Standard action activation, grants total concealment for 10 rounds. It's slightly better than the Greater Cloak of Displacement, as it grants real total concealment. Only works in dark or shadowy conditions.
Obi of Protection (DComp). 48000GP, waist slot. Continuous 20% miss chance if you have the Improved Unarmed Strike feat (or the unarmed strike ability). The only reason this item is worth mentioning despite the price tag is that this is a true miss chance - True Seeing or anything that helps see through concealment doesn't help.

Not recommended:

Blinking armor enhancement (MIC), Shroud of Night (ToM), Continuous custom item of Veil of Shadow (SpC), Major Cloak of Displacement (http://www.d20srd.org/srd/magicItems/wondrousItems.htm#cloakofDisplacementMajor) (DMG).

[Psyren]

It's simple cost-benefit analysis. Look at your available resources, how much AC you can buy with that (including touch), make an educated guess as to how much effective concealment that equates to, then see how much concealment you can buy and compare the two. Do the same for spells and abilities you may have as well. (e.g. compare Fellmist Robe to Incarnate Avatar, or Blur to Mage Armor.)

If you're relying on found gear rather than having access to magic mart then the difference is largely academic - stack whichever one your DM lets you get.

[Snowbluff]

There are ways to augment BAB to overcome AC; but absent things that specifically pierce concealment, there is no way to increase your "roll to not miss".
Factually untrue.

Dispelling, True Strike, Seeking, ignore it, but then you have Blind-Fight (including spells that grant it).

[Red Fel]

Factually untrue.

Dispelling, True Strike, Seeking, ignore it, but then you have Blind-Fight (including spells that grant it).

I chose my language specifically. In fact, in the language you quoted, I acknowledged that certain effects bypass concealment. However, those do not influence the concealment roll; they offer you a way to avoid it completely. That's the part with which you take issue, and clearly I didn't communicate it well.

So let me be clear. Assuming an attack does not bypass concealment, there is very little opportunity to augment the roll itself. For example, if you have 25% concealment, and the enemy doesn't bypass it altogether, it is extremely difficult to augment the roll to decrease their miss chance. (On reflection, there are certain PrCs, such as Deepwood Sniper or Cyre Scout, that can reduce miss chance. But that's an uncommon ability.)

So, technically, my language was correct, if a bit misleading.

[VoxRationis]

Which is better, I think we can all agree, therefore depends heavily upon context. It's possible to stack your armor class bonuses so high that there is only a 5% chance that you will be hit by an enemy (this is particularly true at low levels), thus making it better in those contexts than concealment. But in many campaigns against many monsters, concealment will offer more protection, because higher-level monsters have so many HD that their attack bonus blows away pretty much all armor classes accessible to players.

[Snowbluff]

I don't know about that. My 10 +1 Defending Poison Rings and Greater Magic Weapon seem to disagree.



So, technically, my language was correct, if a bit misleading.
And, depending on the source of the concealment, Energy Drain. :smalltongue:

[GoodbyeSoberDay]

If you want concealment, get the best kind. Greater Concealing Amorpha (http://www.d20srd.org/srd/psionic/powers/concealingAmorphaGreater.htm) grants total concealment and it beats True Seeing and Dispelling.

There are ways to get very high AC, touch or otherwise, mostly by delving through the X stat to Y bonus stuff (http://www.minmaxboards.com/index.php?topic=4369.0) and finding synergistic classes that add to AC. You may end up sacrificing too much offense for your liking, though.

[Snowbluff]

What about beats dispelling?

[GoodbyeSoberDay]

Total concealment means you can't be targeted (unless they beat concealment some other way). And there are ways to laugh at area dispels, namely hiring someone to cast a high CL arcane mark on you a bunch of times.

[Azraile]

do consealment miss and distortion miss affect seporatly?

As to isay....

if you were hidding and got a 50% consealment, and had a spell affect that blured and spread out your image making it look like there was many of you giving you 25% miss change....

would they have to get past the 50% and then the 25% too?

[GoodbyeSoberDay]

In general, miss chances don't stack.

[LordBlades]

Miss chance is certainly more cost effective than AC in the long run. 20 or 50% miss chance has a constant price, while every additional point of AC has an ever increasing price.

[Rubik]

In general, miss chances don't stack.Miss chances due to concealment don't stack. There's no way that the miss chance from Displacement (which throws the image of your body a few feet to the side) doesn't stack with, say, the miss chance for Blink (which is from being on an entirely different plane altogether). They're two entirely different circumstances, and aren't even similar in function. And they all definitely stack with Mirror Image, which isn't technically a miss chance, but it comes to the same thing.

[GoodbyeSoberDay]

Rules Compendium, pg. 32:
If a creature receives miss chances from multiple sources, such as from being incorporeal and having concealment, only the highest miss chance applies.I agree that mirror image isn't a miss chance though.

[Rubik]

Rules Compendium, pg. 32: I agree that mirror image isn't a miss chance though.Yeah, no. That ruling is stupid. And since there have been additional printings of the Core Rulebooks since then, that text is, happily, overruled.

Not to mention that the Rules Compendium is a shifty bit of non-errata to begin with, since not everyone has it, and you don't have to pay for actual errata.

[Azraile]

lol

50/50 to hit me

i hit

ok 50/50 to hit the real me....

o.o... ok i hit.

ok 50/50 not to be conused at the one your hitting is the one you want to hit or not....

GAHHH!!!!

lol that or you could try and say do something rediculous like try and wish for a nexus dragon scale for a shield o.o lol yah 50~92% miss chance sounds nice.

[sleepyphoenixx]

Blindsight defeats both concealment and Mirror Image. Blink is a bit harder since few enemies come with Ghost Strike out of the book, though there's a few who get innate force effects. It also makes you miss, too, unless you use Greater/Improved Blink or use an Ethereal Reaver (CPsi).
There's also the Obi of the White Lotus Master (DrC) which is expensive but only negated when you're denied your Dex to AC.

Spellcasters won't really have a problem getting both at higher levels when you have more spell slots. Mundanes will have to rely on their party or spend money, where miss chance will win because AC is much too expensive to keep effective as a main defense.

[Snowbluff]

Total concealment means you can't be targeted (unless they beat concealment some other way). And there are ways to laugh at area dispels, namely hiring someone to cast a high CL arcane mark on you a bunch of times.

People keep telling me that psionics has been well developed and balanced, but all I see is justification for Mordekain's Disjunction and infinite range Mindsight.

EDIT: Or if the guy was some kind of crazy Arcane Archer with Seeking Arrows.

[DeltaEmil]

Yeah, no. That ruling is stupid. And since there have been additional printings of the Core Rulebooks since then, that text is, happily, overruled.

Not to mention that the Rules Compendium is a shifty bit of non-errata to begin with, since not everyone has it, and you don't have to pay for actual errata.Sounds like a good ruling to reduce book keeping and keeping things in line to a certain degree. It's tedious enough to have to make an attack roll and then a miss chance roll to see if the attack hits in the first place. It would be very annoying to have to make an attack roll and then make three or more miss chance rolls just because the target is invisible and blinking and incorporeal and some more.

[Zirconia]

And there are ways to laugh at area dispels, namely hiring someone to cast a high CL arcane mark on you a bunch of times.

Doesn't Arcane Mark in the PHB say "The mark cannot be dispelled, but it can be removed by the caster or by an erase spell."?


It's tedious enough to have to make an attack roll and then a miss chance roll to see if the attack hits in the first place. It would be very annoying to have to make an attack roll and then make three or more miss chance rolls just because the target is invisible and blinking and incorporeal and some more.

Mid to high level combat tends, in my experience, to be over fairly quickly in terms of rounds, but take awhile in terms of adjuticating all the effects which take place. There tends to be a lot of unusual attacks thrown against layered defenses, and multiple buffs going on both sides. As the player, I am perfectly willing to make the DM roll three times to hit me with the BBEG's no-save death effect, and when possible I'll even throw in a few "please reroll that die, I didn't like the result" type spells. . . :)

[Psyren]

Yeah, no. That ruling is stupid. And since there have been additional printings of the Core Rulebooks since then, that text is, happily, overruled.

Overruled by what? Is there text in the new PHBs (which don't actually contain anything new) that addresses layered miss chances?

[GoodbyeSoberDay]

Doesn't Arcane Mark in the PHB say "The mark cannot be dispelled, but it can be removed by the caster or by an erase spell."? Good point. Magic mouth it is. A little more costly, unfortunately, but it'll do the trick.

[Piggy Knowles]

Concealment is way easier to bypass than high AC, but you'll want concealment anyhow, as it prevents precision damage and most charges and ranged attacks (although the latter only occurs if you have TOTAL concealment). If I could only have one, in general I'd choose concealment unless I was both melee-focused and had another way of avoiding or negating precision damage.

[Rubik]

Concealment is way easier to bypass than high AC, but you'll want concealment anyhow, as it prevents precision damage and most charges and ranged attacks (although the latter only occurs if you have TOTAL concealment). If I could only have one, in general I'd choose concealment unless I was both melee-focused and had another way of avoiding or negating precision damage.Full concealment also prevents any kind of direct targeting, including things like Implosion and Dominate. It also prevents AoOs against you.

[sleepyphoenixx]

Full concealment also prevents any kind of direct targeting, including things like Implosion and Dominate. It also prevents AoOs against you.

Note that Displacement, which is the most common effect used to get total concealment, does not do this. You can get total concealment otherwise but it's generally more expensive, either in gold or other build resources.

[Rubik]

Note that Displacement, which is the most common effect used to get total concealment, does not do this. You can get total concealment otherwise but it's generally more expensive, either in gold or other build resources.I like Greater Concealing Amorpha better anyway.

[Rijan_Sai]

Sounds like a good ruling to reduce book keeping and keeping things in line to a certain degree. It's tedious enough to have to make an attack roll and then a miss chance roll to see if the attack hits in the first place. It would be very annoying to have to make an attack roll and then make three or more miss chance rolls just because the target is invisible and blinking and incorporeal and some more.
I'd like to try and give a reason why these three should have more then one miss-chance roll: you are targeting three different things.

1)Invisibility: Assuming you are aiming at the correct square to begin with, invisibility means that you have a 50% chance that the target is not where you are swinging.

2)Incorporeal: If (1) hits, there is still a 50% chance that (if you are attacking with a non-ghost-touch, non-force magic weapon,) your attack still passes right through the target.

3)Blink: (sill affected by force, not sure about ghost-touch right off hand) Now, if you've hit the correct space on the correct square (1), and your attack didn't just pass right through (2), there is still a chance (20%? I think?) that the target is going to be on another plane of existance right as your attack hits.

[DeltaEmil]

I'd like to try and give a reason why these three should have more then one miss-chance roll: you are targeting three different things.

1)Invisibility: Assuming you are aiming at the correct square to begin with, invisibility means that you have a 50% chance that the target is not where you are swinging.

2)Incorporeal: If (1) hits, there is still a 50% chance that (if you are attacking with a non-ghost-touch, non-force magic weapon,) your attack still passes right through the target.

3)Blink: (sill affected by force, not sure about ghost-touch right off hand) Now, if you've hit the correct space on the correct square (1), and your attack didn't just pass right through (2), there is still a chance (20%? I think?) that the target is going to be on another plane of existance right as your attack hits.I know, but it's still two additional rolls (or more, if there is somehow more miss effects being passed around). D&D 3.5 is already rife with dozens of rolls at the higher level just for one character.

[Rijan_Sai]

I know, but it's still two additional rolls (or more, if there is somehow more miss effects being passed around). D&D 3.5 is already rife with dozens of rolls at the higher level just for one character.

Use several different colored percentile dice and roll them all at once with the attack roll? If one misses, they all miss.

I use this for my BSF with the Murky-Eyed (http://www.d20srd.org/srd/variant/buildingCharacters/characterFlaws.htm#murkyEyed) flaw.

[DeltaEmil]

Use several different colored percentile dice and roll them all at once with the attack roll? If one misses, they all miss.

I use this for my BSF with the Murky-Eyed (http://www.d20srd.org/srd/variant/buildingCharacters/characterFlaws.htm#murkyEyed) flaw.Not all miss chances are necessarily equal.

[Elkad]

A big portion of the problem is sticking to WBL (and magic marts). Much of the other for melee types is the new (3.0?) armor restrictions on Dex, and the relative cheapness of miss chance vs armor enchantments.

If you go AD&D, you still got full dex bonus in plate, miss chance items were rarer, and stacking a bunch of rider effects on armor instead of straight bonuses was harder to do.


In an odd twist of the rules, shooting a guy behind a curtain is often harder than shooting the same guy when he has near total cover from an arrow slit.

I prefer using what is basically the AD&D cover and concealment rules, where it just grants an attack penalty (now an AC bonus)
Something like this.



Target is
Covered
Concealed



25%
+2AC
+1AC


50%
+4AC
+2AC


75%
+7AC
+3AC


90%
+10AC
+4AC


100%
can't attack
+5AC



Then you just have to stick in various effects. Blur (20% miss) becomes 50% concealment. Invisibility is 100%.
A bag of flour on an invisible guy reduces concealment 2 levels.
Faerie Fire reduces it by 3.
Precise Shot and Improved Precise Shot reduce it by 2 levels each.

I haven't used it, but it would make some kind of sense to consider partially corporeal as having some level of cover instead of miss chance as well.

[Rijan_Sai]

Not all miss chances are necessarily equal.

I'm...not really sure what you mean?

Some forms of miss chance are subsumed or made irrelevant by others (blur is essentially subsumed by displacement, while both are fairly useless under invisibility)

That doesn't change what I said about reducing the number of rolls by rolling all the dice at once. Just assign each form of miss chance to a different color, either before you roll, (or even better, before the game starts and use the same color each time you face that form of MC.)
I could be wrong, but I don't think that there are that many different forms of MC that you could't ( potentially) get enough D10s for.

Other than that, I'm just not sure what you are talking about...

[ericgrau]

Which is longer? A rope or a chain? You might think one tends to be longer but that's not a very good answer and discussing it in general is pretty pointless. Compare the cost of each vs. the benefit. Until about level 15 in core AC tends to be a better deal for the money. It's rare for attack bonus to get that ~+10 to needed to exceed AC until very high level, so each +1 helps. Compare 4 +1s to a 24,000 gp cloak of minor displacement with 20% miss chance. But there are some items outside of core that are unusually cheap for both AC and miss chance. So you need to look at each item and compare to each other one. Even past level 15 you still get some AC because the first +1 is much cheaper than later ones. And note that mathematically AC & miss chance don't stack very well, so since you're getting AC first (at minimum a handful of cheap +1s or +2s), so that makes adding on miss chance less worthwhile. For example stopping 50% of blows from each adds up to 75% not 100% hit prevention. So adding on a second form of evasion becomes half as effective as adding more of the same form of evasion and so you gotta wait even longer for that cloak to be cheaper for the same amount of hit prevention. But, again, splatbooks give better deals for both AC & miss chance so that adds confusion. You gotta ask yourself how much of each do you get for how much cost, rather than throwing around hypotheticals like infinity bonuses.

Concealment in particular is nice for stopping random issues like sneak attack. But those are pretty rare among monsters so for that I'd put an obscuring mist on a cheap scroll and forget about it until 4 months later when you have a fight where it applies.

[DeltaEmil]

I'm...not really sure what you mean?

Some forms of miss chance are subsumed or made irrelevant by others (blur is essentially subsumed by displacement, while both are fairly useless under invisibility)

That doesn't change what I said about reducing the number of rolls by rolling all the dice at once. Just assign each form of miss chance to a different color, either before you roll, (or even better, before the game starts and use the same color each time you face that form of MC.)
I could be wrong, but I don't think that there are that many different forms of MC that you could't ( potentially) get enough D10s for.

Other than that, I'm just not sure what you are talking about...Some miss chance numbers aren't equal. If you have concealment, are blinking, and have a windwall spell active, you have miss chance numbers of 20%, 50%, and 30%.

In the end, the problem remains that there are far too many rolls for a single action involved.

[Rijan_Sai]

Some miss chance numbers aren't equal. If you have concealment, are blinking, and have a windwall spell active, you have miss chance numbers of 20%, 50%, and 30%.

In the end, the problem remains that there are far too many rolls for a single action involved.

Okay, so that's why you use some quick, easy referrence for your rolls (like color-coded dice).
*ARBITRAY COLORS - ACTUALL ROLLED NUMBERS INCOMING*
For example, I'm attacking your well-defended character there with a javelin (to go through the Wind Wall). Along with my D20 roll (16+attack mods) I roll my black percentile (for "concealment," let's say: Child of Shadow stance) - 28 + 32 (for Murky-Eyed); my red dice for blink - 56; and my blue dice for Wind Wall - 78.

Depending on how you roll for % (I tend to use high-rolls = good, low = not-so-good), all three of those got through your defenses, and I hit you (also depended on AC, but using the BSF I mentioned earlier, it's probably a good bet that I hit.) All on one flick of the wrist. (If you had been invisible as well/instead of CoS, I would have missed due to the 50% concealment vs 20%.)

I understand it does add an extra layer of complication to an otherwise already complicated system, but it's not that bad of a thing...that's really all I'm trying to say...

[GoodbyeSoberDay]

That's all well and good, but as Psyren pointed out, nothing in the PHB (newly printed or otherwise) contradicts the RC's ruling*. So, I guess when we're looking at whether or not to house-rule away the rules stated in the RC, we consider the following:

Pros: Is consistent with what is being represented in the world. Trying to hit an invisible blinking person should be harder than trying to hit a blinking person, all else equal.
Cons: Slows down gameplay at least a little bit. Decreases balance, as casters are the ones likely to stack miss chances, and they're also better at negating miss chances.

IMO the cons outweigh the pros.

*I should also point out that D&D isn't the best at publishing free errata, but the worst culprit I've seen is Shadowrun. Certain roles, like rigging in 4e (and, it appears, 5e) don't even have functioning rules until you pick up the relevant splatbook.

[Firechanter]

Note that AC does not need to be meaningless either. If your DM agrees that AC should remain relevant, you can go nuts with various sets of Defending Spikes fixed to your armour and animated shield. And maybe even Boot Blades or whatever those shenanigans are called. That way you can improve your regular AC by +10 to +20 points, and a total of ~60 is certainly not an Auto-Hit for anything.

(Of course, to keep the costs manageable, you'll want to have them buffed daily by your resident spellcaster with a Chained GMW.)

Note that I personally prefer all things in moderation, but a set of Defending Armor Spikes is certainly fair game.