Enhancement Bonus To AC?

Looking at the 'Armor Special Abilities' section of Ultimate Equipment on the PRD, the idea of an armor or a shield providing an "enhancement bonus to ac" is mentioned several times:

Shields:

'A shield could be built that also acted as a magic weapon, but the cost of the enhancement bonus on attack rolls would need to be added into the cost of the shield and its enhancement bonus to AC.'

Defiant:

'...Against the designated foe, the item's enhancement bonus to AC is +2 better than its actual bonus...'

Ramming:

'...the shield's enhancement bonus to Armor Class applies to the attack and damage rolls...'

...as far as I am aware, there is no such thing as an armor or a shield providing an enhancement bonus to AC... a numeric bonus on armor provides an enhancement bonus to the armor's armor bonus to AC, and a numeric bonus on a shield provides an enhancement bonus to the shield's shield bonus to AC.

What is going on with this section? How to interpret these abilities?

You're overthinking it. It's pretty straight forward. Yes, the enhancement bonus indirectly rather than directly changes your AC because it modifies the equipment, but it doesn't really change how you interpret it at all.

A +1 defiant shield functions as a +3 shield against the designated for. A +2 Ramming shield adds +2 to attack and damage rolls.
And so on.

Thanks for the reply.

I'm not sure if I am overthinking here... The specifics are actually really important in my view.

If a numeric bonus on armor provides an enhancement bonus to AC (rather than improving the armor's armor bonus to AC), then it stacks with Mage Armor which provides an Armor bonus to AC, and with similar effects.

Also remember that the only reason a numeric bonus on a shield stacks with a numeric bonus on armor is the fact that they are NOT both enhancement bonuses to AC, which would not stack.

A numeric bonus on armor provides an enhancement bonus to the armor's armor bonus to AC.

The the armor's bonus does not stack with Mage Armor. But special abilities of the worn armor will still apply even if the worn armor's armor bonus is overwritten by the +4 from Mage Armor.

So a character with a +2 Leather equipped (2+2 Armor) with Mage Armor cast upon him would have an armor bonus of 4, not 4+2.

An enhancement bonus on a shield enhances that shield's shield bonus.
An enhancement bonus on armor enhances that armor's armor bonus.
The (enhanced) shield bonus adds to the character's AC (except when it doesn't).
The (enhanced) armor bonus adds to the character's AC (except when it doesn't).

There is no enhancement bonus directly to AC, there are only enhancement bonuses to one of the components of AC, such as natural armor, although sometimes an item might provide a typed or untyped bonus directly to AC that may or may not stack depending on type.

Well yes, I agree, which brings me back to my original question: what does that section mean when it talks about an armor/shield's enhancement bonus to AC, given that such a thing doesn't exist?

It's talking about an enhancement bonus to the armor or shield bonus granted by the item. A heavy shield grants a +2 shield bonus. A +1 heavy shield grants a +3 shield bonus, +2 from the shield, and +1 from the enhancement bonus to the shield.

I agree that was the intent. So are we agreed the text is in error when it talks about enhancement bonus to AC, which would be an entirely different thing? This has thrown several of my players (well, three have asked me the question, so I suppose that's 'several', lol).

For bonus points, given that we all *know* that a numeric bonus on armor/shield is an enhancement bonus to the armor/shield bonus to AC provided by that item, can anyone actually find me a PF rules quote that states this? I know it existed in 3.5, but can't for the life of me find it in PF. Don't get me wrong, I am sure that is the rule, but it's killing me that I can't actually find it!

It isn't exactly an "error", since they probably wrote 'to AC' because of the word count.

'...Against the designated foe, the item's enhancement bonus to Armor Bonus/Shield bonus to AC is +2 better than its actual bonus...'

'...Against the designated foe, the item's enhancement bonus to AC is +2 better than its actual bonus...'

It may cause some confusion, but I prefer this alternative to the books being twice as thick.

Lol fair enough. My own stance is that surely all fluff text and images should be cut before we even consider cutting words that add to rules clarity, but point taken. I'm not trying to be anal for the sake of it btw, this kind of thing really slows down play for debates IMHO, when a few extra words could make everything clear.

It's also pretty clear when consider feats like Shield Master:

Add your shield’s enhancement bonus to attack and damage rolls made with the shield as if it were a weapon enhancement bonus.

Well yep that's is clear enough, because your 'shield's enhancement bonus' means 'your shield's enhancement bonus to it's shield bonus to AC'. However, 'your shield's enhancement bonus to AC' has no meaning, so we have to guess the RAI.

Anyway, I'm going to bow out because it's entirely possible I'm just an overly pedantic person. Call it a side effect of being a programmer. In my mind, I'm being precise and logical, but at some point I have to accept the consensus, it's only a matter of time before someone says 'the rules aren't written in legalese'.

On the other hand, I seriously would love a reply to:

'For bonus points, given that we all *know* that a numeric bonus on armor/shield is an enhancement bonus to the armor/shield bonus to AC provided by that item, can anyone actually find me a PF rules quote that states this? I know it existed in 3.5, but can't for the life of me find it in PF. Don't get me wrong, I am sure that is the rule, but it's killing me that I can't actually find it!'

...though, been driving me mad!

Enhancement Bonuses: Enhancement bonuses apply to your armor to increase the armor bonus it provides.]

That should do it.

Thank you!!!! :D

Thank you all in fact. I don't like saying to players "in an ideal world the text should actually say...." unless I am really sure, but now I feel comfortable saying that in this case.

Well yep that's is clear enough, because your 'shield's enhancement bonus' means 'your shield's enhancement bonus to it's shield bonus to AC'. However, 'your shield's enhancement bonus to AC' has no meaning, so we have to guess the RAI.

It can have meaning.

Let me quote from the equipment chapter: "An enhancement bonus on a shield does not improve the effectiveness of a shield bash made with it, but the shield can be made into a magic weapon in its own right."

Some shields will have 2 separate enhancement bonuses, only one of which will be to the armor bonus it provides, the other to the attack and damage bonuses when using it as a weapon.

So, it is sensible to mention which of the shield's magical bonuses apply to which situation, as seen in the examples you yourself quote in the first post. It's not unnecessary, just described a little clumsily.

It's a good point that the shield's enhancement bonus as a weapon does need to be differentiated from its enhancement bonus as a shield to its shield bonus to AC, but I would still suggest that its "enhancement bonus to AC" (never mentioned in the feat, only in the section of UC I pointed to as far as I know) has no meaning, since such a thing never exists.

I would also point out that your point actually means the Shield Master feat text is unclear... when it says "your Shield's enhancement bonus", does it mean as a weapon or as a shield? With a little RAI, we can assume shield, otherwise that part of the feat would be pointless, but it never actually says that. You say "it is sensible to mention which of the shield's magical bonuses apply to which situation", and the feat, erm, doesn't....

Let's also bear in mind here we are talking about the feat that famously by RAW means you can ignore ANY penalties to hit, including those imposed by Power Attack and the like. Not a great example.

Wait, apologies, you weren't necessarily speaking in context of the feat that my post which you quoted was about.

Still, a shield's "enhancement bonus to AC" still has no meaning. A shield's "enhancement bonus to its shield bonus to AC", or a shield's "enhancement bonus as a shield as opposed to as a weapon" has meaning, but they are not the same thing.

I need to clarify my own post, heh.

You said: "...because your 'shield's enhancement bonus' means 'your shield's enhancement bonus to it's shield bonus to AC'..."

I opened with "It can have meaning" while what I meant to say was "It can have a different meaning"

And ironically, I end my post by calling someone else's language clumsy. I hang my head in shame.

My language is very often clumsy! I get what you meant. Right, I really am going to bow out now, I have done this add infininitum far too often :)

If a numeric bonus on armor provides an enhancement bonus to AC (rather than improving the armor's armor bonus to AC).

It improves the armor's armor bonus to AC. You are overthinking it.