Like armor and weapons, if so where can I find it in the rules?
It doesn't, generally, but there are some monsters with special abilities attached to their acid attacks. Some of those abilities specifically target metal armor/weapons.
Also note that different energy types work better/worse against an item's hardness.
No acid that I am deals MORE damage against metal (i.e., I have not seen rules written in that way).
If you are talking about Acid Flask splash weapons, I don't believe they do anything special to metal (my assumption that since the rules for the item say nothing about this, that they do nothing extra). They will do hit point damage (but see below), and if the hit point damage does not exceed the item's hardness, then it does not affect the item. Acid Flasks I believe generally contain a relatively mild acid (as you can put the acid in a normal flask, etc.) so it makes sense it may not affect very hard items.
As Are said, various monsters and attacks have acids that may destroy metal, but this is described specifically in the creature's description (also note that there are some acids that say, work on stone but not metal, and vice versa, etc.).
The rules for item hardness and hit points, etc. are under "Additional Rules."
The note in this section about energy attacks reads,
Energy Attacks: Energy attacks deal half damage to most objects. Divide the damage by 2 before applying the object's hardness. Some energy types might be particularly effective against certain objects, subject to GM discretion. For example, fire might do full damage against parchment, cloth, and other objects that burn easily. Sonic might do full damage against glass and crystal objects.
So, the most annoying (but most correct) answer of all: ask your GM.
As a (ex-)student Chemical Engineering, I can assure everyone that most acids do not affect most metals more than they would affect any other (organic) material.
There are, of course, metals and acids that DO react violently. But those are not the kind of metals you would work into armor or shields.
If there was an acid that would deal extra damage to metals, it would also deal extra damage to wood and flesh. Thus, the 'extra damage' to metals is already worked into the base damage of the acid.
Thanks for the feedback guys. I was just wondering because I'm about to start a home-brewed game with all home-brewed races and 1 of them has breath weapon that deals acid damage and 1 of the characters was wondering if he could melt locks and things like that with his breath weapon. Since it's somewhat up to my discretion, as DeathQuaker pointed out, I may let it deal full damage to certain things like smaller metal objects, parchment, wool, etc. I don't know for sure though.
i thought acid ignores the hardness of metal objects?
i thought acid ignores the hardness of metal objects?
I honestly thought the same thing, I think that's a 3.0/3.5 rule though, but I think I'm going to use it, as well as the Master's Forge stuff from Dragon #358.
EDIT: On a side note would someone need to make a sunder check with a breath weapon if they wanted to destroy a weapon or something with it?
The "rules" for this are discussed under Damaging Objects - it's a DM decision (like fire fully affecting parchment, etc.)
I wouldn't make a broad rule on this.
The rules say energy attacks (most common being acid, cold, electricty, fire and sonic I believe) deal half damage and to divide the damage in two before applying hardness. A DM may decide that a type of energy is more effective against an object. And of course certain attacks might be more effective (IE the rules text of the attack specifically contradict the general rule - Like the spell shatter IIRC). Pages 173-174 in the PFRPG book.
The rules for acid bypassing hardness was from 3.5 where they outlined each of the typical energy attacks and special rules for them, at least I think.
The rules for acid bypassing hardness was from 3.5 where they outlined each of the typical energy attacks and special rules for them, at least I think.
I think that's what I'm thinking of.