How are clockwork prosthetics and necrografts affected by effects that cause magic items to stop working?

Question

Clockwork prosthetics and necrograft arms and legs are the rare examples of magic items to fully replace humanoid limbs, and unless they have a special ruleset on the matter they are as susceptible to antimagic fields or disjunction spells as any other magic item.

For any other magic item, it's easy to predict what happens when they get affected by an effect that suppresses their magic : magic weapons revert to mundane masterwork weapons and other magic items stop having any effect and are totally useless. However, there are no rules about losing limbs except for some rules added by 3rd party publishers (that I tend to avoid except for a few rare exceptions) or I probably missed them, and the rules on prosthetics don't explain what happens either.

If a magic prosthesis gets its magic suppressed does it :

• totally stop working altogether and become inert (and apart from obvious penalties like not being able to wield weapons, how does it affect the wearer ?) ?

• stop giving its specific benefit and still do its job as a limb replacement, imposing no additional penalty to the wearer ?

Answer 1

Clockwork prosthetics should be affected by magic suppression the same way constructs are, and necrograft arms and legs should be affected by magic suppression the same way undead are. Which is to say,

[Antimagic field] has no effect on golems and other constructs that are imbued with magic during their creation process and are thereafter self-supporting (unless they have been summoned, in which case they are treated like any other summoned creatures). Elementals, undead, and outsider are likewise unaffected unless summoned. These creatures’ spell-like or supernatural abilities may be temporarily nullified by the field.

^{(emphasis mine)}

So the graft itself is not affected; a clockwork or necrograft arm continues to function as an arm, at the very least.

As for their special abilities, if those are magical they would be suppressed by antimagic field or dispel magic the same way the spell-like or supernatural abilities of constructs or undead would be. However, most of them seem very much physical functions of the graft. Clockwork arms and legs allow you to lift more, because they are stronger. Undead flesh is often tougher and doesn’t tire, hence the advantages of the arms, legs, and sallowflesh. The strangler’s tongue comes from a mohrg, whose paralysis ability is probably Extraordinary (though it does not actually say, supernatural paralysis is usually explicitly marked as Su; see the lich’s paralyzing touch for example). Even the enhancement bonuses provided by several of the necrografts seem to me to be non-magical in nature: nothing about enhancement bonuses says they must be magical (though they usually are), and the explanation for why they impart these bonuses are all very physical.

Really, the only two I find questionable here are the ghoulgut and gravegland necrografts. These provide more active effects, which could conceivably be separate magic effects suppressed by antimagic field or dispel magic. The ghoulgut still seems pretty physical to me, but I can buy it being magical. The gravegland is even more apparently magical; I could accept an undead organ having non-magical access to negative energy, but it is a stretch. I’d probably allow it if I were GM, but wouldn’t expect others to.

Finally, I would point out that these grafts’ antecedents in 3.5 were more detailed. Grafts appeared first in Fiend Folio, and were also found in Libris Mortis, Lords of Madness, Races of the Dragon, Faiths of Eberron, and Magic of Eberron. These have many more rules, as well as many more grafts, which may be useful to port to these Pathfinder options. In fact, these books actually present two different types of graft: the “old” style in Fiend Folio, Libris Mortis, and Lords of Madness, and the “new” style in Races of the Dragon and Eberron. These differ in a variety of ways, so I leave investigating how or whether you want to use one or both in Pathfinder as an exercise to the reader, but of relevance to this question, both styles explicitly state that the graft, once applied, functions in its entirety even without magic.

Answer 2

Clockwork creatures are usually treated as constructs, which are a type of animated object. If we take the rules for Building and Modifying constructs into consideration, we have the following quote:

Animated Objects

Not all constructs are built with the Craft Construct feat. Spells like animate objects allow a caster to temporarily animate an existing object. These constructs are in many ways weaker than manufactured constructs, as they are susceptible to dispelling and antimagic.

A caster can use the animate objects spell to instantly create a temporary construct. A permanency spell cast upon an Animated Object makes the construct permanent; however, it can still be dispelled or suppressed by antimagic. Craft Construct creates permanent animated objects not susceptible to dispelling and antimagic.

This last line makes golems and clockwork creatures immune to dispell magic and antimagic zones. Even if they lose some of their magical abilities while in there, they will not stop working. This is probably due to the fact that, though animated by magic, they have some sort of self-propelling effect, like how a golem has a small elemental soul inhabiting their body.

This is confirmed again in the spell text of Antimagic Field:

The spell has no effect on golems and other constructs that are imbued with magic during their creation process and are thereafter self-supporting (unless they have been summoned, in which case they are treated like any other summoned creatures).

For Necrograft, I would say that it's the negative energy that empowers the body part, while the magical effects grants the extra benefits, similarly to an animated zombie or skeleton still walking inside an antimagic field because they are permanent creations.

I would go with they remain working for clockworks but you lose out any of the special magical effects granted by the item, as they are self-propelling mechanisms that only need winding and the magic was required for the initial jumpstart and for the magical effects applied on it. While for necrografts, they remain working as a regular limb, but you lose the benefits and retain the penalties for wearing a partial undead body attached to yours.