Mithral and Masterwork reducing ACP

[Gignere]

When you are adjusting the ACP for armors made of mithral, does the ACP adjustment for masterwork and mithril stack?

So for a mithral heavy armor is the ACP reduced by 3 or 4, since all mithral armor are also masterwork?

[Malfus]

I am also curious of this, though I always assumed it was 4 since it specifically mentions that the cost of MW is included but doesn't mention that the benefits of MW are included as well.

[LazarX]

Mithral subsumes masterwork as all mithral armors are masterwork. You just use the factors for mithral alone.

[Mergy]

LazarX is correct. A mithral breastplate for example has an AC penalty of -1, while mithral full plate's AC penalty is reduced to -3.

[Quatar]

It's included, so you get a -3 total.

Elven Chain (aka mithral Chainmail) has -2 ACP, normal chainmail has -5
Mithral Full Plate of Speed has -3 ACP, normal FP has -6

[Jiggy]

Quatar wrote:

Elven Chain (aka mithral Chainmail)

Note: Elven Chain and ordinary mithral chainmail are not quite the same thing.

Being mithral doesn't change proficiency requirements, so mithral chainmail still requires medium armor proficiency.

Elven chain, however, only requires light proficiency.

[Gignere]

Thanks for the quick response and the examples.

[Quatar]

Jiggy wrote:

Quatar wrote:

Elven Chain (aka mithral Chainmail)

Note: Elven Chain and ordinary mithral chainmail are not quite the same thing.

Being mithral doesn't change proficiency requirements, so mithral chainmail still requires medium armor proficiency.

Elven chain, however, only requires light proficiency.

Fair enough, however in all other aspects it's Mithral Chainmail. It's also about 1000 gp more expensive than Mithral Chainmail would be, paying for the proficiency.

However since proficiency has nothing to do with ACP it still works as a demonstration that mithral reduces it by -3.

The full plate example i gave is a plain mithral FP though, and -3 there as well.