Does the Heart of the Metal spell work on natural attacks?

Question

I have a wildshape focused level 12 druid who's main wildshape form is a huge giant octopus, which gets lots of attacks with reach. The main issue I am finding is things with DR. I do have planar wildshape so I can bypass the alignment DR of one enemy/day with smite (provided the alignment is evil/good), but have no way of getting through material DR (until I can afford a natural amulet +3 which. I would love a spell that would treat my natural attacks as cold iron or silver if needed. A wizard is joining the party and I saw this spell: heart of the metal.

I am not sure if this works on my tentacles/bite or not. Do they count as weapons for purpose of the spell?

All over the Pazio forums and elsewhere on the internet I read conflicting information on if natural attacks count as weapons for something like this. I am inclined to believe they do, because it doesn't specify it doesn't, where spells like magic weapon and align weapon specifically say they don't work on natural attacks. Thematically it also makes sense because it specifies it can work on non-metal weapons, and if you can turn a club or bone spear, or whatever else into something that magically counts as metal, why couldn't you do the same for a claw or tooth or tentacle?

On the other hand, I see a lot of forums say that most spells that say "weapon" are using it as shorthand for "manufactured weapon" and therefore natural attacks don't count. One particularly loud member of the group is insisting that spells like magic weapon are specifying it to remind people of the general rule instead of as an exception to it. Was there ever any official ruling on this, or evidence from the books that would suggest one way or another?

I don't think the GM has ruled on this yet. I am of the opinion this should work, based on other spells specifically saying when they don't, but there is that pushy rules-lawyery player in my party that is also GMing a separate instance of the same adventure path for another group, who thinks he knows everything and is louder than everyone, who keeps insisting it doesn't. I need hard evidence one way or another.

Examples of discussions I see online about this:

• https://paizo.com/threads/rzs2umvn?Heart-of-the-Metal-and-Rays

• Is there any spell, feat, or class ability that allows natural attacks to bypass DR/Cold Iron?

https://www.reddit.com/r/Pathfinder_RPG/comments/3q2i1j/is_a_natural_attack_considered_a_weapon/

There were more but I'm having a hard time finding the specific ones at the moment. None of them seemed to have conclusive evidence one way or another, and the other one on stack exchange even lists the spell as a way to have natural attacks go though DR in the accepted answer, but no proof of why this works is given

Answer 1

What is a Weapon

This question really boils down to this: Are Natural Attacks considered Weapons?

Technically there is no official rules text stating that natural attacks are or aren't weapons, but fortunately we have this FAQ from the Pathfinder design team:

Natural attacks are light weapons (though they are never expressly defined as such in the rules).

So yes, natural attacks are weapons of the light category.

Heart of The Metal

So on to your actual question. The Targets property of the spell designates "one weapon per level". In the text of the spell, it specifically states "This is able to affect nonmetal weapons." Thus, the spell is able to target any weapon.

Natural attacks are weapons, and Heart of The Metal can target any weapon, so yes, you can target your natural attacks with this spell. Just make sure you have the material component on hand!

Answer 2

The wording is obnoxiously ambiguous. Natural weapons are weapons, except sometimes “weapon” means “manufactured weapon” and not just any “weapon” and so excludes natural weapons. Maybe. The wording on magic weapon says an unarmed strike is a natural weapon (err...) and not a weapon (uh...), both of which read like nonsense since unarmed strikes are listed on the weapons table, and not the natural weapons table, and follow all the rules for “manufactured” weapons, except this one. There are other, similar exceptions like this, apparently following the (flawed) precedent set by magic weapon.

Even the FAQ gets in on this, in one answer stating that “weapon” covers anything remotely weaponlike (including spells and magic abilities that use touch attacks), and in another answer stating that “weapon” specifically means “manufactured weapon,” and covers nothing but things someone actually built (and maybe, sometimes, unarmed strikes). A third FAQ expressly states that natural weapons are “light weapons,” as baphomet notes in their answer.

Anyway, my read is that magic weapon says “You can’t cast this spell on natural weapons,” and that is what prevents it from being cast on natural weapons. If it didn’t have that line, it could—which is to say, the “Target Weapon touched” bit would otherwise work fine on a natural weapon.

Since heart of the metal uses the same “Weapon” targeting, but does not say “You can’t cast this spell on natural weapons,” you can.

I think the FAQ, confused and confusing as it is, backs this up. The answer claiming “weapon” is shorthand for “manufactured weapon” is talking about not-at-all-weapon-like magic like fireball—the same answer says things like rays and flame blade are sufficiently weapon-like to work with these spells. If heart of the metal can apply to flame blade, it should definitely apply to a tentacle attack.