AC types and stacking


Rules Questions


I want to make sure I have this correct:

There are different types of AC bonuses: Force, Deflection, Armor, Shield, Dodge, Deflection, Natural Armor, Enchantment, Luck, etc.

Bonuses of different types do indeed stack, but bonuses of the same type do not stack (with the rare exception).

According to the spell description, Mage Armor is a Force bonus.
So, would Mage Armor stack with the AC bonus granted from normal armor or a Ring of Protection (deflection bonus)?

Since Mage Armor is Force, it would NOT be stackable with Bracers of Armor or the Shield spell, which are also Force.

So, wearing Bracers of Armor +2 would grant me a continuous +2 Force bonus to AC. But if I were to cast Mage Armor (which grants a +4 Force Bonus), the bonuses would not stack and I would have to take the larger of the two bonuses.

Do I understand this correctly?


No... the force effect of Mage armor or Bracers of Armor is a armor bonus. They do, however, overlap for the purposes of being struck by an incorporeal attack.


Not quite. "Force" is not one of the types of AC bonuses, but a quality of other AC bonuses that allows it to effect etherial creatures.

Mage Armor is an Armor bonus, so it doesn't stack with Bracers of AC or regular armor, which are also armor bonuses. Bracers of AC and Mage Armor are force effects, so they effect etherial creatures, while regular armor does not, even though both produce an armor bonus.

Shield spell produces a force effect that grants a shield bonus.

So bracers of AC +2 would not stack with mage armor but would stack with the sheild spell.


Alright, let's try this again:

Anything with the word "armor" in the description provides an armor bonus (Ex: Full Plate ARMOR, Mage ARMOR, Bracers of ARMOR, etc) and they do not stack.

And anything with the word "shield" in the description provides a shield bonus (Ex: Heavy Steel SHIELD, SHIELD Spell, etc) and they do not stack.

FORCE is just a type of armor bonus that also provides protection against incorporeal attacks.

Pathos wrote:
...the force effect of Mage armor or Bracers of Armor...overlap for the purposes of being struck by an incorporeal attack.

What do you mean overlap? Force bonuses stack against incorporeal attacks?

So a good defensive combination for a spellcaster would be: Ring of Protection, Mage Armor spell, Shield spell and the Dodge feat. Are there any other items that would increase AC and stack?

Can spells like Mage Armor and Shield become permanent with the Permanency spell?

If you cast Mage Armor on yourself, could you also benefit from Bracers of Armor that are enchanted with Light Fortification and Invulnerability?
Must Bracers of Armor be +1 before they can be imbued with other enchantments?


Shadow13.com wrote:

What do you mean overlap? Force bonuses stack against incorporeal attacks?

Actually, both mage armor and bracers of armor are force effects, so you don't get the benefit of both against incorporeal attacks, only the AC bonus of whatever is stronger.

Shadow13.com wrote:


So a good defensive combination for a spellcaster would be: Ring of Protection, Mage Armor spell, Shield spell and the Dodge feat. Are there any other items that would increase AC and stack?

Amulet of natural armor (grants a natural armor bonus, not to be confused with an armor bonus) and there's an ioun stone that grants an insight bonus. A higher Dexterity score always helps too.

Shadow13.com wrote:


Can spells like Mage Armor and Shield become permanent with the Permanency spell?

Under the rules as written, no. You'd need a magic item to give you the continual benefits of these spells. There's a thread or two around covering the shield spell IIRC.

Shadow13.com wrote:


If you cast Mage Armor on yourself, could you also benefit from Bracers of Armor that are enchanted with Light Fortification and Invulnerability?

Yes, you get the light fortification and invulnerability. You'd get the better AC bonus of the mage armor and bracers too.

Shadow13.com wrote:


Must Bracers of Armor be +1 before they can be imbued with other enchantments?

Yes.


Shadow13.com wrote:

Alright, let's try this again:

Anything with the word "armor" in the description provides an armor bonus (Ex: Full Plate ARMOR, Mage ARMOR, Bracers of ARMOR, etc) and they do not stack.

And anything with the word "shield" in the description provides a shield bonus (Ex: Heavy Steel SHIELD, SHIELD Spell, etc) and they do not stack.

FORCE is just a type of armor bonus that also provides protection against incorporeal attacks.

Pathos wrote:
...the force effect of Mage armor or Bracers of Armor...overlap for the purposes of being struck by an incorporeal attack.

What do you mean overlap? Force bonuses stack against incorporeal attacks?

So a good defensive combination for a spellcaster would be: Ring of Protection, Mage Armor spell, Shield spell and the Dodge feat. Are there any other items that would increase AC and stack?

Can spells like Mage Armor and Shield become permanent with the Permanency spell?

If you cast Mage Armor on yourself, could you also benefit from Bracers of Armor that are enchanted with Light Fortification and Invulnerability?
Must Bracers of Armor be +1 before they can be imbued with other enchantments?

Dodge bonuses always stack, so things that grant them will stack with dodge feat.

Not everything with "armor" is mutually exclusive. You can have "Natural Armor" (usually an amulet) that stacks. The amulet grants an enhancement bonus to the Natural Armor you already have, (0 unless you have something that grants it or are a weird race.)

If you read the descriptions of mage armor or shield, they say what type of bonus they grant.
Mage Armor: "+4 armor bonus to AC"
Shield (spell): "+4 shield bonus to AC"
Amulet of natural Armor: "enhancement bonus to natural armor"
Barkskin (druid spell): "enhancement bonus to natural armor" - does not stack with the amulet
Ioun stone (Dusty Rose): "+1 insight bonus to AC"
Ring of Protection: "deflection bonus to AC"

And if you have Barcers of Armor with light fortification and Mage Armor spell, , you must choose 1 to apply. You do not get +4 from mage armor and light fortification. The Bracers description specifically states they do not stack.


Lathiira wrote:

Actually, both mage armor and bracers of armor are force effects, so you don't get the benefit of both against incorporeal attacks, only the AC bonus of whatever is stronger.

Gotcha.

Thanks for answering all my questions.

I'm playing in a campaign where people hate magic and they immediately target the spellcaster in battle, so I have a feeling that AC is going to be important!


Shadow13.com wrote:
Lathiira wrote:

Actually, both mage armor and bracers of armor are force effects, so you don't get the benefit of both against incorporeal attacks, only the AC bonus of whatever is stronger.

Gotcha.

Thanks for answering all my questions.

I'm playing in a campaign where people hate magic and they immediately target the spellcaster in battle, so I have a feeling that AC is going to be important!

@Caineach. Good catch, it's what I get for working from memory regarding special qualities in bracers.

Shadow13: One recommendation. Don't rely on armor exclusively. Armor won't save you from fireball spells. Or from enervation spells. At higher levels, opponents will hit you pretty easily even with the best gear described in the core rules. Higher-level spellcasters need to also rely on having people run interference while they use their reality-bending powers. That's why you have fighters. Or you can summon monsters to keep enemies away. Also, if you're having problems staying away from opponents, use magic to give yourself new mobility options such as flight. Finally, cloaks of displacement, blur spells, and displacement spells give opponents a flat chance to miss you regardless of how good they are at hitting. This trumps AC for protection from enemy attacks.

RPG Superstar 2013 Top 32

Caineach wrote:


And if you have Barcers of Armor with light fortification and Mage Armor spell, , you must choose 1 to apply. You do not get +4 from mage armor and light fortification. The Bracers description specifically states they do not stack.

Actually, you don't get to choose, you must use the item with the higher armor bonus. You can't turn on your +3 bracers of light fortification over your existing Mage Armor spell. The Mage Armor AUTOMATICALLY turns off the bracers AND their extra effect.

It doesn't say what happens if both armor modifiers are the same value, but I'd imagine the extra effect would stay on because the total effective + of the item is higher.

So, if you're fighting someone who's wearing +3 bracers of armor with the Invulnerability effect, and you don't have a magic weapon to overcome the DR, cast mage armor on your enemy.


Caineach wrote:

If you read the descriptions of mage armor or shield, they say what type of bonus they grant.

Mage Armor: "+4 armor bonus to AC"
Shield (spell): "+4 shield bonus to AC"

Aha! I see that now.

I was focusing so much on the "Force" effect that I was overlooking that crucial piece of text.
Thanks for pointing that out.

Caineach wrote:


And if you have Barcers of Armor with light fortification and Mage Armor spell, , you must choose 1 to apply. You do not get +4 from mage armor and light fortification. The Bracers description specifically states they do not stack.

I understand that the AC bonuses do not stack.

If I am wearing +3 Bracers of AC and I cast Mage Armor, I would use the +4 bonus granted by Mage Armor because that is the higher of the two bonuses.
I got that.

Here's the part I don't get:

Why wouldn't the Bracers' other enchantments, like Light Fortication, also apply? I know that AC bonuses do not stack, but these enchantments are not AC bonuses, so therefore they should also apply even if I cast Mage Armor.


Shadow13.com wrote:

Alright, let's try this again:

Anything with the word "armor" in the description provides an armor bonus (Ex: Full Plate ARMOR, Mage ARMOR, Bracers of ARMOR, etc) and they do not stack.

And anything with the word "shield" in the description provides a shield bonus (Ex: Heavy Steel SHIELD, SHIELD Spell, etc) and they do not stack.

FORCE is just a type of armor bonus that also provides protection against incorporeal attacks.

Closer... although not all things with the word ARMOR in the description provide an armor bonus, Amulet of Natural Armor spring to mind which provides a "Natural Armor" bonus (Yes I think it is kind of dumb to use two such close terms), nor does everything that says SHIELD preovide a shield bonus (The shield of faith spell provides a deflection bonus for example). but you essentially have the correct idea. every item or effect that provides an AC bonus should tell you someplace in the description (not always in the name) what type of bonus it provides. Force is not a type of armor bonus, it is a descriptor that can be added to several different bonus types, for example shield is a force effect that provides a shield bonus, in all cases force effects are fully functional against incorporeal creatures.

Shadow13.com wrote:


Pathos wrote:
...the force effect of Mage armor or Bracers of Armor...overlap for the purposes of being struck by an incorporeal attack.
What do you mean overlap? Force bonuses stack against incorporeal attacks?

What he means is that if you have mage armor active (+4 armor bonus), and are wearing Chain mail (+6 armor bonus) you only get the +6 to your AC under normal circumstances, however if you are attacked by an incorporeal creature, which normally ignores armor bonuses to your AC unless they come from force effects, you still get the +4 from the mage armor spell because it is a force effect.

In other words a person (assuming dex 10 and no other defensive items or effects) in chain mail is ac 16, against incorporeal attackers (like a ghost or shadow) he is ac 10

The same person with chainmail and mage armor is still AC 16, but against the ghost or shadow his AC would be 14.

Shadow13.com wrote:
So a good defensive combination for a spellcaster would be: Ring of Protection, Mage Armor spell, Shield spell and the Dodge feat. Are there any other items that would increase AC and stack?

amulet of natural armor (providing a natural armor bonus), staff of power (provides a luck bonus to AC).

Shadow13.com wrote:
Can spells like Mage Armor and Shield become permanent with the Permanency spell?

They are not on the list of spells under the Permanency spell description, but the list ends with the quote that "The GM may allow other spells to be made permanent." So it is really up to your Game Master. in my 3.5 game in the past I have allowed mage armor (but not shield) to be made permanent with the permanency spell.

Shadow13.com wrote:
If you cast Mage Armor on yourself, could you also benefit from Bracers of Armor that are enchanted with Light Fortification and Invulnerability?

Yes, use the mage armor armor bonus, or the armor bonus granted by the bracers which ever is higher, the special abilities applied to the bracers will work only of the armor bonus provided by the bracers is higher then that of the mage armor.

Shadow13.com wrote:
Must Bracers of Armor be +1 before they can be imbued with other enchantments?

Yes, the bracers must have at least a +1 armor bonus before special abilities can be applied to them.

Hope that helps.

RPG Superstar 2013 Top 32

Lathiira wrote:


Shadow13: One recommendation. Don't rely on armor exclusively.

I'd go one further and say don't rely on armor AT ALL for your enemy casters.

If you bump their AC up to a level where they're going to be able to avoid getting hit by the main fighter, they're STILL probably going to lose the fight, and all you've done is handed your players a massively overpowered defensive magic item for them to use.

Lathiira's tactics are ESSENTIAL for an NPC caster. Make your caster hard to reach, whether by terrain or obstacles, and if they insist in rushing past everything to get to the caster, then make the party pay heavily for ignoring the obstacles. That's how casters survive. If it gets to a contest between the fighter's attack bonus and the caster's AC, you've already lost.

RPG Superstar 2013 Top 32

Shadow13.com wrote:


Why wouldn't the Bracers' other enchantments, like Light Fortication, also apply? I know that AC bonuses do not stack, but these enchantments are not AC bonuses, so therefore they should also apply even if I cast Mage Armor.

Because it says so in the Bracers' item description. If you're the DM, you have the option to ignore that. I think it's probably there for game balance. Buy cheap +1 bracers and pump them up with +9 of extra effects... sounds too easy.


Shadow13.com wrote:

Here's the part I don't get:

Why wouldn't the Bracers' other enchantments, like Light Fortication, also apply? I know that AC bonuses do not stack, but these enchantments are not AC bonuses, so therefore they should also apply even if I cast Mage Armor.

By specific rule.

From D20PFSRD - Bracers of Armor:
If a creature receives a larger armor bonus from another source, the bracers of armor cease functioning and do not grant their armor bonus or their armor special abilities. If the bracers of armor grant a larger armor bonus, the other source of armor ceases functioning.


Shadow13.com wrote:
Lathiira wrote:

Actually, both mage armor and bracers of armor are force effects, so you don't get the benefit of both against incorporeal attacks, only the AC bonus of whatever is stronger.

Gotcha.

Thanks for answering all my questions.

I'm playing in a campaign where people hate magic and they immediately target the spellcaster in battle, so I have a feeling that AC is going to be important!

How about disguise...so you don't appear to be a spell caster? Have some clothes cut to look like leather armor. Obviously spell casters don't wear armor, so you can't be one, especially since you carry that long scabbard on your hip...

in addition, get a mithral or darkwood buckler. No Armor penalty, and spell failure is reduced to 0, so it's free AC, even without Shield proficiency.


Shadow13.com wrote:
Why wouldn't the Bracers' other enchantments, like Light Fortication, also apply? I know that AC bonuses do not stack, but these enchantments are not AC bonuses, so therefore they should also apply even if I cast Mage Armor.

it is a game balance issue, to prevent somebody from putting on +5 heavy fortification full plate, and then also getting the effects of invulnerability and spell resistance (17) by simply adding them to a set of bracers of armor +1 and wearing them too.


Shadow13.com wrote:


Here's the part I don't get:
Why wouldn't the Bracers' other enchantments, like Light Fortication, also apply? I know that AC bonuses do not stack, but these enchantments are not AC bonuses, so therefore they should also apply even if I cast Mage Armor.

Ah. I missed a bit of information in the descriptive text for the Bracers of AC:

If a creature receives a larger armor bonus from another source, the bracers of armor cease functioning and do not grant their armor bonus or their armor special abilities.

So, if you get a higher AC from another source, the Bracers' feelings get hurt and they completely shut down, leaving you SOoL.
Those are clearly the most sensitive bracers in the world.

Liberty's Edge

Robert Young wrote:


By specific rule.

From D20PFSRD - Bracers of Armor:
If a creature receives a larger armor bonus from another source, the bracers of armor cease functioning and do not grant their armor bonus or their armor special abilities. If the bracers of armor grant a larger armor bonus, the other source of armor ceases functioning.

Interestingly enough the rule says nothing about them being equal in power. Small loophole. I'm not fond of this rule anyways, probably why I noticed the minor point.


graywulfe wrote:
Robert Young wrote:


By specific rule.

From D20PFSRD - Bracers of Armor:
If a creature receives a larger armor bonus from another source, the bracers of armor cease functioning and do not grant their armor bonus or their armor special abilities. If the bracers of armor grant a larger armor bonus, the other source of armor ceases functioning.

Interestingly enough the rule says nothing about them being equal in power. Small loophole. I'm not fond of this rule anyways, probably why I noticed the minor point.

+1 Chain shirt with a +1 bonus ability and +5 bracers with a +1 bonus ability, both functioning don't really provide any more power than a +1 X with +2 ability is why the loophole isn't much of a loophole, since it's most likely cheaper to have the second option.


Shadow13.com wrote:


There are different types of AC bonuses: Force, Deflection, Armor, Shield, Dodge, Deflection, Natural Armor, Enchantment, Luck, etc.

If you're looking for another bonus to AC for a wizard, Reduce Person gets you +2 dex (+1 dodge AC) and +1 size AC. (As well as bonuses to hide among other things)


Shadow13.com wrote:
Lathiira wrote:

Actually, both mage armor and bracers of armor are force effects, so you don't get the benefit of both against incorporeal attacks, only the AC bonus of whatever is stronger.

Gotcha.

Thanks for answering all my questions.

I'm playing in a campaign where people hate magic and they immediately target the spellcaster in battle, so I have a feeling that AC is going to be important!

Obscuring mist, Displacement, blur, mirror image, and invisibility are your friends. You wont be able to easily get your AC up into the range of full BAB missing your regularly, but thins that provide miss chance are your friends. A high enough AC that itterative attacks miss is useful, though not necessary.


Caineach wrote:
You wont be able to easily get your AC up into the range of full BAB missing your regularly, but thins that provide miss chance are your friends. A high enough AC that itterative attacks miss is useful, though not necessary.

+1.

Minor cloaks of displacement are a godsend to any character that really, really doesn't want to get hit.


I'm diggin' these alternatives, especially the cloak of displacement. Too bad it's $24,000. :(

The spells are a great idea, but they take so much time to cast. If I anticipate getting into a battle, I could cast some spells ahead of time. But if I get thrown into an impromptu battle, it would take several rounds of buffing before I could even go on the offensive. Are there better ways around that?


Shadow13.com wrote:

I'm diggin' these alternatives, especially the cloak of displacement. Too bad it's $24,000. :(

The spells are a great idea, but they take so much time to cast. If I anticipate getting into a battle, I could cast some spells ahead of time. But if I get thrown into an impromptu battle, it would take several rounds of buffing before I could even go on the offensive. Are there better ways around that?

Think of that 24K price tag as an investment, in exchange 20% of the attacks you suffer in life are negated. Not so expensive now eh?

Extend Spell is a metamagic feat, also available in rod form, that might let you cast some of these spells and make them stick around longer. Good scouting (by the rogue, an arcane eye spell, however you like) reduces the odds of impromptu battles occurring. Also, if your party is doing its job, you won't need defense on the first round necessarily-fighters, rogues, and others will provide some of that. And when all else fails, remember this: "the best defense is a good offense".


what class and level is your character? Perhaps that would help us tailor our advice to you better....


cwslyclgh wrote:
what class and level is your character? Perhaps that would help us tailor our advice to you better....

My character is a Sorcerer 6.

The other players are Fighter 6 and Rogue 6.

Dex = 16
Defensive Feats: Dodge, Mobility
Defensive Equipment: +2 Ring of Protection, Healing Belt (from the 3.5 Magic Item Compendium).
Survival strategy:
Cast Mage Armor and Shield before battle, hide behind the fighter and rogue, use Mobility to escape if an enemy catches me.

I don't have any Summon Monster spells, but I do have Reduce Person.


Shadow13.com wrote:
cwslyclgh wrote:
what class and level is your character? Perhaps that would help us tailor our advice to you better....

My character is a Sorcerer 6.

The other players are Fighter 6 and Rogue 6.

Dex = 16
Defensive Feats: Dodge, Mobility
Defensive Equipment: +2 Ring of Protection, Healing Belt (from the 3.5 Magic Item Compendium).
Survival strategy:
Cast Mage Armor and Shield before battle, hide behind the fighter and rogue, use Mobility to escape if an enemy catches me.

I don't have any Summon Monster spells, but I do have Reduce Person.

Your AC right now is not bad for a caster. At 24, a fighter will miss a decent ammount of the time (+4 str, +6 bab, +2 weapon, +1 weapon training = 50%). An Amulet of Natural Armor is really the only other cheap option for your AC. I recomend picking up Combat Casting so you can cast defensively with spells like color spray to make monsters who get too near you sad. A buff or 2 to avoid damage is never bad the first round or 2, and most you can cast on allies. The fighter and rogue will never complain about bonus miss chance from blur or displacement. Haste will boost everyone's AC by 1, as one of its weakest benefits. Terrain control will start coming into effect soon, with wall spells, a decent way to prevent attacks. Illusions are also your friend, major image can create a new combatant on the field to trick opponents.


when you get to 7th level think about taking fly as your 2nd third level spell, it can be very useful for getting out of the way of opponents and giving you a chance to buff your self up (though in clear terrain it is not so helpful against archers).


Unfortunately, Sorcs don't get very many spells, so I guess it's important to find a balance between defensive and offensive spells.

Right now, I've got 4 offensive spells and the rest are all utility spells. I should probably start stocking up on defensive spells.
Illusion and Terrain spells seem to be quite the awesome.


Shadow13.com wrote:

Unfortunately, Sorcs don't get very many spells, so I guess it's important to find a balance between defensive and offensive spells.

Right now, I've got 4 offensive spells and the rest are all utility spells. I should probably start stocking up on defensive spells.
Illusion and Terrain spells seem to be quite the awesome.

You've got some tough choices to make regarding spells. What bloodline did you choose? (I'm hoping Arcane, you get Invisibility as a bonus spell known at 5th level, and at higher levels you get a couple additional spells known that you can choose!).


Robert Young wrote:
Shadow13.com wrote:

Unfortunately, Sorcs don't get very many spells, so I guess it's important to find a balance between defensive and offensive spells.

Right now, I've got 4 offensive spells and the rest are all utility spells. I should probably start stocking up on defensive spells.
Illusion and Terrain spells seem to be quite the awesome.

You've got some tough choices to make regarding spells. What bloodline did you choose? (I'm hoping Arcane, you get Invisibility as a bonus spell known at 5th level, and at higher levels you get a couple additional spells known that you can choose!).

Elemental - Air


Your bloodline is providing you with mostly offensive options at this level.

Suggested spells: 1st level-Protection from Evil, 2nd level-Invisibility, 3rd level-Haste (as mentioned above Fly is also appropriate). All of these spells can also benefit the other members of your party as the situation dictates.

When you get 4th level spells (and above) consider the Summon Monster spells for their versatility.

Unfortunately, your bloodline paints you into a corner somewhat.


Robert Young wrote:

Your bloodline is providing you with mostly offensive options at this level.

Suggested spells: 1st level-Protection from Evil, 2nd level-Invisibility, 3rd level-Haste (as mentioned above Fly is also appropriate). All of these spells can also benefit the other members of your party as the situation dictates.

When you get 4th level spells (and above) consider the Summon Monster spells for their versatility.

Unfortunately, your bloodline paints you into a corner somewhat.

I just hit lv 6, so I can probably swap out one of my offensive spells for a defensive spell.

With some AC enhancing items and a defensive spell or two, I can probably wing it to lv 7, where I can get more defensive spells.

I think I'll hold off on Invisibility and wait for Greater Invisibility.


Shadow13.com wrote:

I just hit lv 6, so I can probably swap out one of my offensive spells for a defensive spell.

With some AC enhancing items and a defensive spell or two, I can probably wing it to lv 7, where I can get more defensive spells.

I think I'll hold off on Invisibility and wait for Greater Invisibility.

Sounds reasonable. Treantmonk's Guide to Wizards is an excellent treatise on spell selection. There will be instances where the Sorcerer benefits more or less from certain spells than the Wizard, but, as an overall guide, it's an outstanding resource with all of the Pathfinder Core spells in one spot. I'm no good with the linky, but a quick search for 'guide to wizards' should do the job.

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