[3.5] Fixing the AC System?

[Timeless Error]

I've never played in an adventure past level two (yeah, I'm pretty inexperienced), so I haven't noticed any problems myself, but I've heard tell of the Armor Class system deteriorating towards the higher levels. I like the idea of AC, and it becoming obsolete at high-level play is something that I dread, so I'd like to ask the Playground: how could I go about correcting this while still maintaining game balance?

Thanks very much in advance!

EDIT to give an example: I flipped to a random monster in the recent Pathfinder Bestiary 2 (the banshee), and it had an AC of 26 and an attack of +26. The monster would only miss itself on a natural 1.

[ericgrau]

Hmm 1st play before you start fixing. Second read up and find some actual numbers before you believe what you hear. People do pretty crazy stuff when they don't do those first. Average monster AB goes up by 25 over 20 levels. +5 armor AC, +5 shield AC, +5 ring of protection AC, +5 amulet of natural armor AC, +5 misc. like haste, mithril, dusty rose prism ioun stone, etc. There, 25. Without a shield you can still get dodge half the primary attacks and most of the secondaries. With one it averages to 3/4 the primaries and almost all the secondaries. On average. Both vary by monster though. Problem comes from PCs/DMs who don't know how to spread out their AC among all 4-5 sources to get more for less money.

[Shpadoinkle]

First idea that comes to mind: Give everything an unnamed bonus to AC, which is based on what their BAB is.

If this number is the same as their BAB, then you have full-BAB classes who are only able to be hit by other full-BAB classes, meaning rogues are pretty much totally screwed against them unless they have some magic gadget that raises their BAB to compensate. This will pretty much lead to spells like Scorching Ray and whatever else requires an attack roll never being cast, unless the AC bonus doesn't apply to touch attacks, which seems to me to kind of defeat the purpose.

So, personally I'd start off with the AC bonus being equal to half your BAB, which seems kind of low, but you can always raise it later if it doesn't bring things up to where you want them (and players are less likely to complain about it if it's too low at first, then raised, than they are if you set it too high at first, then lower it.)

Another option would be to simply make Combat Expertise not require a feat to use, but if you DO take the feat, you gain AC at a 1-to-2 ratio (i.e. each point of BAB you sacrifice gives you +2 to your AC instead of +1.) When your BAB reaches a certain point, say +9 or so, the ratio becomes 1-to-3.

These are just off the top of my head, I've never playtested them or anything.

[RaggedAngel]

You don't need to worry about AC deterioration; it's only really a problem if the DM allows too much homebrew and too many third-party sources.

The one other thing you have to consider is that while a character's AC can be very high, it's much harder to increase a charater's saves. So, while a typical attack with a longsword will miss at level 17, an opponent's Wail of the Banshee can kill the character, even if their AC is over 9000.

[ForzaFiori]

The problem with AC, from what I've seen, isn't that the monsters that try to smack you around can easily beat it. It's that in the higher levels, there are MUCH more monsters and classes capable of simply ignoring armor, rendering it useless. At that point, when crazy powerful touch spells, and save-or-die/suck spells are being hurled around, your +5 fullplate isn't really gonna do much.

[wayfare]

I've instituted class based AC bonuses in my games, which make certain things easier, but overall wizards are still blowing folks up with touch attacks.

AC isn't so much broken, as there are easy ways for non-combat classes to buff it, ignore damage, or simply avoid conflict with melee characters while still blowing those characters up.

[Soren Hero]

i'm of the school of thought that miss chance>AC at mid to high levels (around 12)...monsters at that level tend to have ridiculous attack numbers..take an Elder Earth Elemental for instance...a slam attack at +27, and a +37 grapple modifier...if ur AC is 25, the monster hits u on everything but a natural 1...but with miss chance, its much harder to hit u...take mirror image for example...it grants u between 1-8 images which gives u at worst a 50% miss chance and at best a 89% miss chance. even though the AC for the images is low (10+your dex mod+size mod), you have a better chance at avoiding attacks from the Elemental than relying solely on your armor bonus. a +5 adamantine fullplate costs over 40K and it gives u +13 AC...whereas a wand of mirror image at CL 6, costs 9000, and gives a 50-86% miss chance.

[Zeta Kai]

Hmm 1st play before you start fixing. Second read up and find some actual numbers before you believe what you hear. People do pretty crazy stuff when they don't do those first. Average monster AB goes up by 25 over 20 levels. +5 armor AC, +5 shield AC, +5 ring of protection AC, +5 amulet of natural armor AC, +5 misc. like haste, mithril, dusty rose prism ioun stone, etc. There, 25. Without a shield you can still get dodge half the primary attacks and most of the secondaries. With one it averages to 3/4 the primaries and almost all the secondaries. On average. Both vary by monster though. Problem comes from PCs/DMs who don't know how to spread out their AC among all 4-5 sources to get more for less money.

You forgot about improvements to Dexterity, but other than that, I agree wholeheartedly.

Also, if you haven't played D&D 3E past level two, then you haven't really played it at all. You've gone through CharGen, had a 4-session trial run, & that's it. You've barely scratched the surface of what the game's all about.

[Timeless Error]

Thanks everyone for the replies!


Hmm 1st play before you start fixing. Second read up and find some actual numbers before you believe what you hear. People do pretty crazy stuff when they don't do those first. Average monster AB goes up by 25 over 20 levels. +5 armor AC, +5 shield AC, +5 ring of protection AC, +5 amulet of natural armor AC, +5 misc. like haste, mithril, dusty rose prism ioun stone, etc. There, 25. Without a shield you can still get dodge half the primary attacks and most of the secondaries. With one it averages to 3/4 the primaries and almost all the secondaries. On average. Both vary by monster though. Problem comes from PCs/DMs who don't know how to spread out their AC among all 4-5 sources to get more for less money.

Thanks for the advice and the numbers. This is probably a question that I should have waited on until later into the campaign that I am about to run.


First idea that comes to mind: Give everything an unnamed bonus to AC, which is based on what their BAB is.

If this number is the same as their BAB, then you have full-BAB classes who are only able to be hit by other full-BAB classes, meaning rogues are pretty much totally screwed against them unless they have some magic gadget that raises their BAB to compensate. This will pretty much lead to spells like Scorching Ray and whatever else requires an attack roll never being cast, unless the AC bonus doesn't apply to touch attacks, which seems to me to kind of defeat the purpose.

So, personally I'd start off with the AC bonus being equal to half your BAB, which seems kind of low, but you can always raise it later if it doesn't bring things up to where you want them (and players are less likely to complain about it if it's too low at first, then raised, than they are if you set it too high at first, then lower it.)

Another option would be to simply make Combat Expertise not require a feat to use, but if you DO take the feat, you gain AC at a 1-to-2 ratio (i.e. each point of BAB you sacrifice gives you +2 to your AC instead of +1.) When your BAB reaches a certain point, say +9 or so, the ratio becomes 1-to-3.

These are just off the top of my head, I've never playtested them or anything.

Wow, lots of good ideas! I think I'll settle for the second one (AC bonus = half BAB).


You don't need to worry about AC deterioration; it's only really a problem if the DM allows too much homebrew and too many third-party sources.

The one other thing you have to consider is that while a character's AC can be very high, it's much harder to increase a charater's saves. So, while a typical attack with a longsword will miss at level 17, an opponent's Wail of the Banshee can kill the character, even if their AC is over 9000.

OK, I'm beginning to realize that the AC problem isn't as bad as it sounds. As to save-or-dies, they annoy me as a DM (both when my players use them to end encounters instantaneously as they did repeatedly in the last adventure I DM'ed) and when I kill a player with them (which seems unfair and fun-ruining), so I'm not as worried about that.


The problem with AC, from what I've seen, isn't that the monsters that try to smack you around can easily beat it. It's that in the higher levels, there are MUCH more monsters and classes capable of simply ignoring armor, rendering it useless. At that point, when crazy powerful touch spells, and save-or-die/suck spells are being hurled around, your +5 fullplate isn't really gonna do much.

As I mentioned earlier in my post, I don't throw around save-or-dies lightly. Concerning touch spells, would not that be fixed by the untyped AC bonus equal to half BAB (as suggested by Shpadoinkle)?


I've instituted class based AC bonuses in my games, which make certain things easier, but overall wizards are still blowing folks up with touch attacks.

AC isn't so much broken, as there are easy ways for non-combat classes to buff it, ignore damage, or simply avoid conflict with melee characters while still blowing those characters up.

Hm...so in your first sentence, you say that no matter how much you boost AC, you're still quite vulnerable (especially to touch spells), and in your second sentence, you say that AC isn't actually broken. Am I misinterpreting your post, or are you contradicting yourself?


i'm of the school of thought that miss chance>AC at mid to high levels (around 12)...monsters at that level tend to have ridiculous attack numbers..take an Elder Earth Elemental for instance...a slam attack at +27, and a +37 grapple modifier...if ur AC is 25, the monster hits u on everything but a natural 1...but with miss chance, its much harder to hit u...take mirror image for example...it grants u between 1-8 images which gives u at worst a 50% miss chance and at best a 89% miss chance. even though the AC for the images is low (10+your dex mod+size mod), you have a better chance at avoiding attacks from the Elemental than relying solely on your armor bonus. a +5 adamantine fullplate costs over 40K and it gives u +13 AC...whereas a wand of mirror image at CL 6, costs 9000, and gives a 50-86% miss chance.

Hm, that opens some interesting options...maybe all classes could gain a small miss chance that scales with level? That might work. What do you think?


You forgot about improvements to Dexterity, but other than that, I agree wholeheartedly.

Also, if you haven't played D&D 3E past level two, then you haven't really played it at all. You've gone through CharGen, had a 4-session trial run, & that's it. You've barely scratched the surface of what the game's all about.

Well, to be honest, I've done a lot more than that. I've created dozens and dozens of characters of various levels and perused many important D&D-related threads, such as the tier system. I've also homebrewedBut you're right that I don't have much experience in actual play. What do you think "the game's all about"? From what I can gather, it's more complicated than that, and the purpose of the game differs from person to person.

--

Thanks once again for all the replies so far!

[Ziegander]

To reiterate what has been said, getting AC that can reliably turn away monster's attacks isn't that difficult (though it might be argued that it costs too much gold). The real problem, as has been said, is that at mid to high levels you either have Brutes with higher than average attack bonuses that plow through your armor, or you have every other monster that targets the party with save or dies/sucks and blankets the surrounding area with battlefield control.

So to "fix" the AC system you'd probably have to find a way to make Armor Class help to protect against the spells and supernatural abilities enemies throw around in the level 10ish to 20 range.

One thing that I like is the idea that Shields add to touch AC and to Reflex saves against Reflex halves effects. Armor could do something against certain Fortitude saves. Will saves is obviously the outlier, maybe deflection bonuses to AC could apply to Will saves. Shrug.