Total AC when under Beast Shape X spell

[Aziraya Zhwan]

Sorry to have yet another Polymorphed AC question posted, but every single one I've come across focuses on different aspects than what I'm unclear on. I'll keep this as specific and to the point as possible.

My dex in my normal form is 10. I'm using Beast Shape I to transform into a medium-sized wolf. I don't have any other effects going on that would increase or decrease my AC.

Do I get the +2 natural armor from the wolf's stat block as well as the +2 natural armor explicitly listed from the spell, giving me an AC of 14? Or do I only get the +2 listed in the spell, meaning my AC is 12?

[Diego Rossi]

Only the +2 listed by the spell.

[Aziraya Zhwan]

Thank you for the quick answer!

[thorin001]

To answer your overall question, there are a few things that alter your AC when polymorphed.
1) you lose all armor and shield bonuses. (Aside from a few exceptions.)
2) You lose all natural armor bonuses from your form (such as being a nagaji.)
3) You replace the size bonus of your old form with that of your new form.
4) You adjust your Dex as specified in the spell description.
5) You get the higher of natural armor granted by the spell or class ability. Thus a high level draconic sorcerer would keep his +4 natural armor bonus when turning into a wolf, but have the +6 from the spell if he turned into a triceratops.
6) You should keep most other bonuses to AC such as deflection, insight, and dodge. Though you might lose access to the dodge bonuses provided by some feats (like dodge) if your dex drops too low.

[Diego Rossi]

thorin001 wrote:

5) You get the higher of natural armor granted by the spell or class ability. Thus a high level draconic sorcerer would keep his +4 natural armor bonus when turning into a wolf, but have the +6 from the spell if he turned into a triceratops.

Source?

AoN wrote:

You also lose any class features that depend upon form, but those that allow you to add features (such as sorcerers that can grow claws) still function.

Assuming that you are speaking of a Sorcerer with a Draconic bloodline, Dragon Resistances add FEruew that isn't dependant from your form:

AoN wrote:

Dragon Resistances (Ex): At 3rd level, you gain resist 5 against your energy type and a +1 natural armor bonus. At 9th level, your energy resistance increases to 10 and natural armor bonus increases to +2. At 15th level, your natural armor bonus increases to +4.

It adds to your new form's natural armor bonus; it doesn't overlap it.

[Lelomenia]

‘Bonuses of the same type don’t stack’ etc

You keep your class feature armor bonus, but that doesn’t change stacking rules.

[Azothath]

Bonus:
→Magic Rules, Bonus Types {subset of CRB Magic Rules below}
→Bonus Types (from Designing Spells) {a convenient list of Bonus types}

Bonus: Bonuses are numerical values that are added to checks and statistical scores. Most bonuses have a type, and as a general rule, bonuses of the same type are not cumulative (do not “stack”)—only the greater bonus granted applies. from Common Terms.

Bonus Types: Usually, a bonus has a type that indicates how the spell grants the bonus. The important aspect of bonus types is that two bonuses of the same type don’t generally stack. With the exception of dodge bonuses, most circumstance bonuses, and racial bonuses, only the better bonus of a given type works (see Combining Magical Effects). The same principle applies to penalties—a character taking two or more penalties of the same type applies only the worst one, although most penalties have no type and thus always stack. Bonuses without a type always stack, unless they are from the same source. from CRB Magic Rules(link above & below), Special Spell Effects. See also Combining Magical Effects (scroll down).

Comment: often there's a maximum of +/- 5 on bonuses/penalties.

Polymorph:
The rest depends on Polymorphing Rules.
→CRB Magic Rules which contains Spell Descriptions, School (Subschool) {contains description of the arcane schools}, Transmutation, Polymorph.

Form means creature/monster type or Race. This means ongoing spells that affect creatures (rather than humanoids) will continue to function if your new 'magical disguise'/polymorph is non-humanoid.
While under the effects of a polymorph spell, you lose all extraordinary and supernatural abilities that depend on your original form (such as keen senses, scent, and darkvision), as well as any natural attacks and movement types possessed by your original form. You also lose any class features that depend upon form, but those that allow you to add features (such as sorcerers that can grow claws) still function. While most of these should be obvious, the GM is the final arbiter of what abilities depend on form and are lost when a new form is assumed. Your new form might restore a number of these abilities if they are possessed by the new form. from Polymorph School

Melding gear: this got clarified with →Magic Item Body Slots(MIBS). PFS has a slightly different list →Org Play MIBS due to Cassians and odd Familiars...

I'll add the very good but incomplete guide Polymorphamory - The Love of Changing Form also on PF1 Guides at ZG

[Diego Rossi]

I was convinced the sorcerer's natural armor was a "natural armor increase", like it is for the Dracon disciple, but it says that the sorcerer's "natural armor bonus increases to +2" (etc.).
It effectively gives a fixed value.