Using RAW, can the Polymorph Any Object spell allow a Simulacrum to gain in power?

Question

I was unable to delete this and post the revised question. I apologize to those who have invested time in answering, but I feel that this is now more evidence based than presentation based and better suited for the medium on which it is hosted.

Does this evidence prove that a simulacrum can be healed and gain in power and ability?

1. Does WOTC (as described in this article: Rules of the Game: Constructs) see a Simulacrum as having the construct traits of an artificial being, and that it is regarded not as an object but as a creature of the same type from which it was duplicated, having both awareness and perception?

A construct is a kind of creature.

A creature has both a Charisma score, which gives it self-awareness, and a Wisdom score, which gives it perception.

Construct Traits : Artificial Beings: An object animated with the animate objectspell is a construct. So are most creatures that are built through some artificial means rather than bred, cloned, sprouted, or created through any natural process.

The simulacrum spell creates a duplicate of some other creature and the duplicate has the same creature type as the original.

2. Does a polymorphed subject loses the qualities of its previous form?

Alter self: You keep all extraordinary special attacks and qualities derived from class levels, but you lose any from your normal form that are not derived from class levels.

3. Is it true that characteristics of a being are classified as either normal or special, with special being categorized as either an attack or a quality?

4. Is it true that special abilities/qualities are categorized as either being natural, extraordinary, spell-like, or supernatural?

The terms Ability and Quality are synonymous in their descriptions.

Natural Abilities: This category includes abilities a creature has because of its physical nature. Natural abilities are those not otherwise designated as extraordinary, supernatural, or spell-like.

From the Monster Manual glossary:

Extraordinary abilities are nonmagical, don’t become ineffective in an antimagic field, and are not subject to any effect that disrupts magic. Using an extraordinary ability is a free action unless otherwise noted.

Spell-like abilities are magical and work just like spells (though they are not spells and so have no verbal, somatic, material, focus, or XP components). They go away in an antimagic field and are subject to spell resistance if the spell the ability resembles or duplicates would be subject to spell resistance..

Supernatural abilities are magical and go away in an antimagic field but are not subject to spell resistance.

5. Does the simulacrum inability to gain in power go away in an anti-magic field? If it does not, then is it safe to say that a simulacrum's inability to heal or gain in power is not a spell-like or supernatural quality?

If it is not spell-like or supernatural, is it safe to assume that a simulacrum's inability to heal or gain in power is either a natural quality or extraordinary quality?

6. Assuming the WOTC are the authority on the matter and a simulacrum is an artificial construct, which is a construct trait, is it reasonable to say that the traits of a simulacrum would be categorized as a special quality?

7. Does the spell simulacrum describe the inability to gain in power or ability in a way that suggests it is not a trait inherent to its being a simulacrum?

A simulacrum has no ability to become more powerful. It cannot increase its level or abilities.

8. Are the traits (normal or extraordinary) of a simulacrum defined in the description of the spell that created it and the creature type that the simulacrum was duplicated from?

I believe this is what using RAW looks like. Without conjecture or "leading the witness" to the best of my ability. I have numbered the points of evidence for your convenience to relay how you would answer/approach the questions.

Following that, using polymorph any object, does a simulacrum become a human in every regard (since a human has no extraordinary, supernatural, or spell-like qualities to speak of) and lose the traits of its former form?

Please support your arguments with RAW and an explanation, as per the title.

Answer 1

3rd Edition Polymorph doesn't work like that.

The line of Polymorph spells in 3rd Edition were built to be very selective in how they transform a creature from one thing into another. The result is an ugly patchwork of rulings, and a lot of cross referencing.

When it comes to special traits and abilities, you have to look all the way back to Alter Self. Here's what it says about gaining/losing abilities:

You retain all supernatural and spell-like special attacks and qualities of your normal form, except for those requiring a body part that the new form does not have (such as a mouth for a breath weapon or eyes for a gaze attack).

You keep all extraordinary special attacks and qualities derived from class levels, but you lose any from your normal form that are not derived from class levels.

It's a little unclear, because the Simulacrum doesn't have a stat block, but you'd have to make the claim that the "cannot spend XP" is an extraordinary quality, which is tricky because those are described like this:

Extraordinary abilities are nonmagical, though they may break the laws of physics.

If it is a quality, it's likely to be a natural ability, which is maintained by polymorph, etc.

A more likely interpretation is that this restriction is simply a spell effect, which polymorph doesn't touch at all.

This is not to say that this couldn't be something you and your DM agree to, though! It sounds reasonably well thought out in that regard.

Baleful Polymorph

An interesting quirk is that this might work with Baleful Polymorph. That spell has the following text:

The subject takes on all the statistics and special abilities of an average member of the new form in place of its own except as follows

Your DM would need to rule that the spending XP restriction is part of the Simulacrum's statistics, and not a spell effect placed upon it. You'd also have to be okay with spending the XP as a toad.

Imperfect Polymorphs

A troll's regeneration IS an extraordinary ability. A troll polymorphed into a rock loses it, and a human into a troll gains it. It seems to me that whatever the subject was before polymorph, it is no more, and it is in fact, turned from one creature into another. Not just the form, not just the type, completely. ?

This is incorrect. A troll polymorphed into a human would, indeed, lose its regeneration because:

You keep all extraordinary special attacks and qualities derived from class levels, but you lose any from your normal form that are not derived from class levels.

But a human polymorphed into a troll wouldn't gain regeneration, because:

You do not gain any extraordinary special attacks or special qualities not noted above under physical qualities, such as darkvision, low-light vision, blindsense, blindsight, fast healing, regeneration, scent, and so forth.

In other words, a human polymorphed into a troll is fundamentally different than an actual troll.

For another example, look at a Wraith. It has this supernatural ability:

Create Spawn (Su)
Any humanoid slain by a wraith becomes a wraith in 1d4 rounds. Its body remains intact and inanimate, but its spirit is torn free from its corpse and transformed. Spawn are under the command of the wraith that created them and remain enslaved until its death. They do not possess any of the abilities they had in life.

If you polymorph a wraith into a human, and that "human" kills someone, the victim will still rise as a wraith in 1d4 rounds. Because

You retain all supernatural and spell-like special attacks and qualities of your normal form, except for those requiring a body part that the new form does not have (such as a mouth for a breath weapon or eyes for a gaze attack).

If you polymorphed a human into a wraith, and that human kills someone, the victim will not rise as a wraith. Because

You do not gain any supernatural special attacks, special qualities, or spell-like abilities of the new form. Your creature type and subtype (if any) remain the same regardless of your new form. You cannot take the form of any creature with a template, even if that template doesn’t change the creature type or subtype.

Again, a wraith polymorphed as a human is not actually a human. A human polymorphed into a wraith isn't actually a wraith.

Ability Types

So what type of ability is "the simulacrum can't gain XP?" There's really only five options:

• Extraordinary Ability
• Spell-like Ability
• Supernatural Ability
• The effect of a spell
• Natural Ability (None of the above; it's just an ability)

The only option above that polymorph can remove is an extraordinary ability. Which seems the least fitting for a magical restriction on a magical snow person.

You could make the argument. "Due to the nature of it's neurons, the snow brain is unable to learn new skills." But getting there requires you to pass over several better options (I'd rank them: it's a spell effect, it's a natural ability, it's a supernatural ability, it's an extraordinary ability) and add quite a bit of interpretation of your own. At that point you might as well just say it's a DM's call.

By the Numbers

1. Does WOTC see a Simulacrum as having the construct traits of an artifical being.

   No. A simulacrum is not a construct. The only mention of it in the linked article is a sentence stating that it's not an example of the construct type:

   Not all artificial creatures are constructs. Spells such as animate dead and create undead produce undead creatures, not constructs. The simulacrum spell creates a duplicate of some other creature and the duplicate has the same creature type as the original. In general, a construct is a unique kind of creature, not a previously existing creature brought back from death or an attempt to copy another creature. A construct also usually is built up, piece by piece (except in the case of an animated object) from inert materials.

   and that it is regarded not as an object but as a creature of the same type from which it was duplicated

   Yes, a Simulacrum is a creature, with a creature type matching the creature from which it was duplicated. Per the spell, and the text in the linked article.

2. Does a polymorphed subject loses the qualities of its previous form?

   Speaking strictly: No. A polymorphed creature does lose some qualities of its previous form (e.g. extraordinary special attacks and qualities not derived from class levels in your quote), but it does not lose "qualities" in general.

3. Is it true that characteristics of a being are classified as either normal or special, with special being categorized as either an attack or a quality?

   Yes, when referring to abilities that are written in a character's stat block. However, other effects may modify a creature (even permanently). E.g. the effects of Feeblemind would not be classified as a special quality.

4. Is it true that special abilities/qualities are categorized as either being natural, extraordinary, spell-like, or supernatural?

   Mostly yes. Special abilities technically don't include natural abilities.

5. Does the simulacrum inability to gain in power go away in an anti-magic field? If it does not, then is it safe to say that a simulacrum's inability to heal or gain in power is not a spell-like or supernatural quality?

   An interesting question, useful if you want to argue that the XP restriction is a supernatural ability, but difficult to answer. The Simulacrum itself, as something that is "partially real[, created from] extradimensional energy" (per the Shadow keyword) probably doesn't exist within an anti-magic field.

   If it is not spell-like or supernatural, is it safe to assume that a simulacrum's inability to heal or gain in power is either a natural quality or extraordinary quality?

   There are two interpretations here. The first is the most literal: Simulacrum creates a creature whose stat block is the same as the target creature, and then applies a spell effect to that stat block granting control, limiting healing, and adding the XP restriction. In that case, the answer is no.

   The other interpretation is that the spell creates a creature whose stat block is the same as the target creature, with the addition of the control, healing, and XP restrictions as an additional quality on that creature. In that case it would have to be natural, extraordinary, spell-like, or supernatural. So the answer is still no, but a more qualified no.

6. Assuming the WOTC are the authority on the matter and a simulacrum is an artificial construct, which is a construct trait, is it reasonable to say that the traits of a simulacrum would be categorized as a special quality?

   Your given assumptions are invalid. The Simulacrum is not a construct (in game terms), and has no traits of the construct type.

7. Does the spell simulacrum describe the inability to gain in power or ability in a way that suggests it is not a trait inherent to its being a simulacrum?

   No. See the answer to question 5, above.

8. Are the traits (normal or extraordinary) of a simulacrum defined in the description of the spell that created it and the creature type that the simulacrum was duplicated from?

   The traits of the original target remain qualities of the Simulacrum. The additional traits provided by the Simulacrum spell may be qualities of the Simulacrum, but may also be a spell effect imposed on the Simulacrum.

Answer 2

There is no simulacrum type

Simulacra are, according to the Rules of the Game by Skip Williams, the same type as their "original":

The simulacrum spell creates a duplicate of some other creature and the duplicate has the same creature type as the original.

So changing the type of a simulacrum will not remove restrictions innate to simulacra. In particular, it will never become able to become more powerful, because it is a simulacrum, and simulacra don't have the ability to become more powerful:

A simulacrum has no ability to become more powerful. It cannot increase its level or abilities.

You can increase its Intelligence by Polymorph Any Object it into you, since there is nothing preventing YOU from making it more powerful. However, it still cannot level up nor increase in power without external manipulation.

The simulacrum CAN gain XP, without any Polymorph shenanigans, it just cannot spend them.

Answer 3

TL;DR The simulacrum spell creates game elements that aren't called abilities therefore have no designations. The DM determines how the simulacrum spell's game elements interact with the wider game (see #5).

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I've done my best to preserve the words if not the spirit of the original propositions made over the course of the asker's extended argument. If I have misrepresented something, that misrepresentation is accidental not malicious. And if I have rephrased something, that rephrasing was to increase mechanical accuracy or (I hope!) clarity not to dismiss or to obfuscate. Just a head's up: This runs about 2,700 words. Grab a drink.

1. Mostly no

The article does not say to add traits from the construct type to a simulacrum

The Wizards of the Coast Rules of the Game Web column "All About Constructs (Part One)" by Monster Manual author Skip Williams on Artificial Beings, in part, says

An object animated with the animate object spell is a construct. So are most creatures that are built through some artificial means rather than bred, cloned, sprouted, or created through any natural process.

Not all artificial creatures are constructs. Spells such as animate dead and create undead produce undead creatures, not constructs. The simulacrum spell creates a duplicate of some other creature and the duplicate has the same creature type as the original. In general, a construct is a unique kind of creature, not a previously existing creature brought back from death or an attempt to copy another creature. A construct also usually is built up, piece by piece (except in the case of an animated object) from inert materials.

In a paragraph that begins by saying that not all artificial creatures possess the type construct (Monster Manual 307), the article says that a simulacrum's creature type is the same as the original's creature type. The article does not otherwise mention simulacra. (And parts two and three don't mention simulacra at all.) There is also no mention in the article of artificial life generally gaining one or more traits of the construct type—or gaining the construct type proper—due to the creature's status as artificial life. Artificial life includes creatures that possess the construct type, but that's not all that artificial life includes. The article says so. In fairness to the remainder of the proposition, a simulacrum is not an object, a simulacrum is a creature, and the typical simulacrum possesses awareness and perception.

2. Mostly no

The subject of a polymorph spell may retain and may lose some of its extraordinary, supernatural, and spell-like abilities

In context, the alter self spell says

You retain all supernatural and spell-like special attacks and qualities of your normal form, except for those requiring a body part that the new form does not have (such as a mouth for a breath weapon or eyes for a gaze attack). You keep all extraordinary special attacks and qualities derived from class levels (such as a barbarian’s rage ability), but you lose any from your normal form that are not derived from class levels (such as a dragon’s frightful presence ability).

In the first sentence, supernatural and spell-like modify both special attacks and qualities, and special modifies both attacks and qualities. In the second sentence, extraordinary modifies both special attacks and qualities, and special modifies both attacks and qualities. The sentence's adjectives are coordinating with the nouns, not isolating the word qualities. To be extra clear, the first sentence discusses supernatural special attacks, supernatural special qualities, spell-like special attacks, and spell-like special qualities, and the second sentence discusses extraordinary special attacks and extraordinary special qualities.

This is not to say that there's no ambiguity here (cf. here). Yes, instead of writing, "You must wear black shoes and socks," a writer should write, "You must wear black shoes and black socks," if the writer wants the reader to wear black shoes and black socks, but the writer doesn't have to. I mean, if it's a solemn occasion, then the reader can infer that the writer is mandating black socks instead of allowing the reader to wear his snazzy neon unicorn socks.^1,2

Inferring from the alter self spell's context is also possible. Reading the boldfaced sentences above as isolating the words qualities from their adjectives means that the reader must bring meaning to the term quality—and the game doesn't define the standalone term quality or use it in any consistent way. Thus, when the spell is used, the game halts until the DM decrees what, in that DM's opinion, constitutes a quality. On the other hand, if read the way that I suggest, the sentences marshal defined game terms, a player can largely adjust his affected PC's character sheet without DM input at all, and play can continue. Legalistically, the sentences can be read as isolating qualities, but, practically, reading them that way creates new problems in sentences that are about solving problems. (By the way, I'd agree totally that qualities is standalone if it were to have come first—for example, "You retain all qualities and supernatural and spell-like special attacks of your normal form…"—, but that's not what it says.)

3. Half no

There are only attack options (né special attacks) and special qualities

The game puts in a creature's stat block pretty much everything mechanical about a creature into the stat block's entries Special Attacks and Special Qualities (see Monster Manual 6) until Complete Psionic (Apr. 2006) when creature stat blocks see the Special Attacks entry replaced by the entry Attack Options.^3,4 (All of these, by the way, are under the umbrella of what the game calls special abilities (see PH 80, DMG 289, and MM 315). I'll be using the term special abilities later instead of a more complicated one.)

I can imagine a reader wanting to read the terms special attacks and special qualities as implying that there are nonspecial attacks and nonspecial qualities. That's actually pretty reasonable. However, I would urge that reader revisit #2 (above) and realize that if qualities is not a standalone term then the reader can modify his affected PC according to the alter self spell (and subsequent spells) without knowing a creature's nonspecial qualities at all. In other words, if you agree with #2 then this proposition moot, and if you don't agree with #2, you'll probably think the rest of this answer is nonsense…

4. All yes

A special ability is either a natural ability, an extraordinary ability, a spell-like ability, or a supernatural ability

…Except maybe this part. At least we agree on this. Thank heavens.

5. I'd say no, but another might say yes

I'd not expect a simulacrum's differences from the original to be suppressed in areas of antimagic

Beyond a simulacrum having "only one-half of the real creature’s levels or Hit Dice (and the appropriate hit points, feats, skill ranks, and special abilities for a creature of that level or HD)," the 7th-level Sor/Wiz spell simulacrum [trans] (Player's Handbook 279–80) creates a duplicate that exists under the following game elements:

• "You [the caster] must make a Disguise check when you cast the spell to determine how good the [simulacrum's] likeness is [to the original]. A creature familiar with the original might detect the ruse with a successful Spot check (opposed by the caster’s Disguise check) or a DC 20 Sense Motive check.
• "At all times the simulacrum remains under your [i.e. the caster's] absolute [but nontelepathic] command.
• "A simulacrum has no ability to become more powerful. It cannot increase its level or abilities.
• "If reduced to 0 hit points or otherwise destroyed, it [the simulacrum] reverts to snow and melts instantly into nothingness.
• "A complex process requiring at least 24 hours, 100 gp per hit point, and a fully equipped magical laboratory can repair damage to a simulacrum."

The game doesn't classify these game elements. This is the crux of the argument. There are at least three choices:

• The game elements are imposed upon the simulacrum instantaneously by the simulacrum spell. They are not special abilities. They are beyond them but predicated on the simulacrum being a simulacrum. Since the simulacrum spell's game elements are not otherwise addressed by the game, the DM determines how other game elements interact with them.

  In this way, a DM could rule (possibly whimsically and in a way that could make me leave that DM's campaign) that one or more of these game elements are suppressed in areas of antimagic. Likewise, a DM could rule that one or more of these game elements are affected by form-changing effects like the polymorph any object spell. It's possible—and totally okay—to agree with the rest of this answer, end up here, and do whatever you want anyway. Just puttin' that out there.

• The game elements are part of the simulacrum spell. They are not special abilities. Changing these game elements requires some way (probably original spell research) of changing the simulacrum spell or some way (probably an adventure) of changing the underlying fundamental laws that govern the whole of Simulacrum Club.⁵

• The game elements become one or more of the resultant simulacrum's special abilities. They aren't classified by the simulacrum spell as natural abilities, extraordinary abilities, spell-like abilities, or supernatural abilities, though, so that makes them, by default, natural abilities: "Natural abilities are those not otherwise designated as extraordinary, supernatural, or spell-like" (PH 180). To be clear, natural abilities are unaffected by areas of antimagic, and natural abilities are unmentioned by (therefore, unless the DM rules otherwise, unaffected by and not lost to) the alter self spell, the polymorph spell, the polymorph any object spell, and even the shapechange spell.

Undoubtedly, there are other alternatives, too. Personally, though, I lean toward the last as I've found that the most playable. (I group the simulacrum spell's game elements into one special ability, name the natural ability simulacrum, add that special ability to the simulacrum's Special Qualities entry in its stat block, and call it good enough. That's worked for me, and I've had no complaints, but I've also never had a PC try to remove that special ability—the natural ability simulacrum—from a simulacrum.)

Until writing this answer, though, I hadn't realized there were alternatives to the way I've always done it. I now think that such alternatives are possible—even if I disagree with them, don't like them, and won't be using them.

6. Yes and no

A simulacrum is artificial but not a construct due to the simulacrum spell alone

The game is the authority on simulacra (although the spell that makes them could certainly be more detailed). Also, a simulacrum is artificial. A simulacrum is not necessarily a construct, though, because, as per the article, a simulacrum "has the same creature type as the original."⁶ For emphasis: A simulacrum does not possess the construct type because it is artificial life. (#1, above, addresses this.) Further, while each creature that possesses the construct type "is an animated object or artificially constructed creature," not all animated objects and artificially constructed creatures must possess the type construct. "Not all artificial creatures are constructs," says the article.

7. Irrelevant

One reader may infer from the description of an unclassified game element that a game element is a special ability, but another reader can disagree

The proposition is this: "Does the spell simulacrum describe the [simulacrum's] inability to gain in power or ability in a way that suggests it [the inability] is not a trait inherent to its [the simulacrum] being a simulacrum?" This is kind of the wrong question. It makes no difference how the simulacrum spell describes the inability to become more powerful; what matters is that the game simply doesn't say what kind of game element that inability to become more powerful is.

Also, traits in this context typically means game elements derived from a creature's race, type, or subtypes (q.v. MM 5 and 296). The simulacrum spell does not say that the spell gives the resultant simulacrum traits (as per #1, above). (If the simulacrum spell did say that it granted traits but nothing else, then those traits would be undesignated special abilities therefore natural abilities; see #5, above.)

8. Mostly yes

A simulacrum's special abilities are determined by modifying the original creature according to the simulacrum spell, but game elements due solely to the simulacrum spell must be further adjudicated by the DM

The argument's proposition is this: "Are the traits (normal or extraordinary) of a simulacrum defined in the description of the spell that created it and the creature type that the simulacrum was duplicated from?" As previously stated, there are no other kinds of special abilities beyond natural abilities, extraordinary abilities, spell-like abilities, and supernatural abilities (see #4, above); there are no normal qualities to contrast with special qualities (see #3, above). And, again, the simulacrum spell itself adds no further traits to the resultant simulacrum (see #1, above).

That said, this proposition leads back to the DM determining what kind of game elements the simulacrum spell creates (see #5). In sum, does the spell create those game elements for the cosmos, or individually for each separate simulacrum? If the latter, then are the game elements special abilities? If they aren't, then the DM rules how the simulacrum spell's game elements interact with other game elements.

"So about the polymorph any object spell…"

To be super-extra clear, a simulacrum doesn't gain extra traits due to the simulacrum spell (see #7); a simulacrum possesses the traits of the original because it's largely a duplicate of the original with the original's type (see #1—and, wow, was that, like, a week ago?). Also, the 8th-level Sor/Wiz spell polymorph any object [trans] (PH 262) inherits many limits from the 4th-level Sor/Wiz spell polymorph [trans] (PH 262) therefore the 2nd-level Sor/Wiz spell alter self [trans] (PH 197), so the polymorph any object spell has very little extra oomph in this particular regard over the lower-level polymorph spell (q.v. here).

With that in mind, whether a simulacrum of a creature can be changed by a polymorph spell et al. into the same or a different creature yet not beholden to the simulacrum spell's game elements depends on the DM's adjudication the simulacrum spell's game elements (as per #5, and I told you it was the crux of the argument).

In my campaigns, were a wizard to cast a polymorph any object spell on a human commoner 1 simulacrum in an effort to change it into a human commoner 1 that's not beholden to the game elements of the simulacrum spell, the polymorph any object spell would fail (as per Spell Failure (PH 171)) because the desired result is impossible: natural abilities are unaffected by the polymorph any object spell (see #5, above). In my campaigns, the polymorph any object spell just can't do that any more than a summon monster spell can crush an orc with an orca. But maybe in yours it can.

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¹ This inference may not apply in all areas to all solemn occasions. I know. I'm a native Californian.
² "Hey, in that description, are those socks with snazzy neon unicorns on them, snazzy socks with neon unicorns on them, socks in a snazzy neon with unicorns on them, or socks that have on them unicorns that are both snazzy and neon?" Ask the DM.
³ Complete Psionic also kicks puppies. And hates unicorns.
⁴ I'll link to the self-congratulatory Web column justifying the new stat block when I can find it.
⁵ I'm imagining the neutral god of simulacra hatching a plot to change the fundamental laws of simulacra so that simulacra gain souls therefore giving the god more power than any other god due to the god's nigh-infinite horde of mirror mephits. I'd switch to the middle bullet to run that campaign. That sounds pretty spiffy.
⁶ The simulacrum spell's material components include "some piece of the creature to be duplicated (hair, nail, or the like)." Thus it's technically possible to create a simulacrum that duplicates any creature that the caster can get a piece of—including a creature that possesses the construct type. (I'd still ask the DM before I spent my XP, though.) This doesn't change this answer at all. Even a simulacrum of a construct (therefore possessing the construct type) still must reckon with the game elements due to its creation by the simulacrum spell.

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Note: Thank you for posing this question. I hadn't realized before how much of this I'd internalized until I tried to articulate it to someone who viewed it differently. I also appreciate the patience of any reader who made it all the way here.

Answer 4

A quick d20srd search for "Improving Monsters" reveals:

When a monster adds a class level, that level usually represents an increase in experience and learned skills and capabilities.

A DM may adjust the CR of a creature to be higher, essentially adjusting that average grizzly to be a fearsome battle-worn grizzly bearing the scars of a challenging life. It’s a matter of experience, not magically poofing the stats and abilities of encounters. The more experienced the foe, the greater the experience the players gain, the less experienced the foe, the less they gain. Simple.

Gaining experience is a normal, natural quality inherent to all living creatures.

I interpret abilities and qualities to be interchangeable, and special to mean anything that’s particular to that creature’s statistics.

You know what's not normal? Lacking the ability to gaining experience! If it’s not natural, then it’s either extraordinary, supernatural, or spell-like. These categories defined by raw are the only viable categories as they stay within the framework outlined in the core books that anyone can follow.

Natural Abilities

This category includes abilities a creature has because of its physical nature. Natural abilities are those not otherwise designated as extraordinary, supernatural, or spell-like.

That there spells it out for me.

Alter self tells you exactly what it keeps, all of which are a part of a monster’s statistics. Stat block is just another way of saying monster statistics.

You keep your hp’s, your level, class, your ability scores, alignment, base attack bonus and base save bonuses. You keep your supernatural and spell-like special attacks and qualities, and you keep extraordinary special attacks and qualities derived from class levels. You keep your mind, your memories, you know how to communicate, and you keep any spellcasting ability.

That is what you keep. That’s it! Everything else changes.

Spell-like abilities and supernatural abilities are magical in nature, and both disappear in an anti-magic field. Since everyone agrees, myself included, that the simulacrum limitations don’t go away in an anti-magic field, the limitations can’t be a magical property. Players could theorize that the limitation is some persistent spell effect that is neither extraordinary, natural, supernatural, nor spell-like, but that would be purely speculative and outside the framework of the core books. Even then, it still follows that such a magical effect would go away in an anti-magic field just as effectively as every other magic in this universe.

Therefore, to me at least, these simulacrum limitations must be an extraordinary quality. And extraordinary qualities not derived from class levels are lost when under the effects of alter self/polymorph.

"A level 7 simulacrum human fighter." Not being able to be healed by ordinary means, not being able to gain experience, that isn’t a part of the fighter class. So yes, this restriction is lost when the target is under the effects of alter self, polymorph, or polymorph any other.

Dissecting the points of the OP’s argument that isn't covered with my answer above:

The spell simulacrum is the magic that brings forth the simulacrum into being. But what is a simulacrum creature? By the spell’s definition, it’s a partially real duplicate of the original creature. The WOTC article and the respondents so far agree that a simulacrum is of the creature type that it has duplicated. Let’s take it from there.

A human simulacrum will be used as in the OP’s example; it has no supernatural or spell-like qualities to complicate matters. A simulacrum human has all the traits that a human possesses as defined by its race, including all special abilities for a creature of that HD. This includes all natural, extraordinary, supernatural, and spell-like qualities. Had the simulacrum been formed into a dragon, it would have the dragon breath, flight, spell resistance, everything that the dragon race of that HD qualifies for.
It is that creature. Mostly.

But every human can be healed by natural means, and every human can gain experience. If the simulacrum were simply and only its creature type, then it too would benefit from these features! As it doesn’t, it must be something else besides just a human being.
Let’s not neglect the part that says it’s “partially real”. A part of it isn’t real. That’s to say a part of it isn’t human.

This inability to heal by normal means or gain experience must come from this “not real” part. I think this is what the OP was alluding to, and probably could have just come out to say it rather than leaving breadcrumbs and trusting us all to figure it out ourselves.

Here a simulacrum is more than just one thing: what it is, and what it’s made of.

What is it made of, this unreal part? The spell’s school is Illusion (Shadow):

A shadow spell creates something that is partially real from extradimensional energy. Such illusions can have real effects. Damage dealt by a shadow illusion is real.

It’s made from extradimensional energy, but we can’t just take that into consideration and exclude all other definitions in the book. We can say that a human being has the creature type human and close the book there, or we can also observe how it’s an animal, and how it’s also a mammal. We can look at them all and find how they are interlinked:

The OP was likely linking the part that “isn’t real” to the article’s definition of what an artificial being is, that being:

Artificial Beings: An object animated with the animate object spell is a construct. So are most creatures that are built through some artificial means rather than bred, cloned, sprouted, or created through any natural process.

Bred, cloned, sprouted, created through a natural process; all of these imply undergoing a process of being grown or developed. A simulacrum was made. The OP isn’t saying that the simulacrum is a construct or has construct traits, that would contradict the nature of its duplication. She’s saying that a simulacrum is an artificial being regarded as the creature type human.
An animal regarded as the creature type human. See the correlation?
One doesn’t negate the other. Both animals and artificial beings have qualities that classify them as such, as described above, both having a type human.

The source of this creature’s inability to heal normally or gain experience isn’t from the human part, it’s from the artificial part, the shadow part. A simulacrum is a human, in terms of its physical descriptors and capabilities contingent upon its race, but it’s also an artificial being partly made of shadow stuff.

interesting note Using the core books prior to this article, the clarification of artificial being was only made in reference to a construct, and players/dm’s were encouraged to consider any creature not born or hatched to be a “construct type”.

Construct: A construct is an animated object or artificially constructed creature. Constructs have average combat ability and hit points, and very poor saving throws, but they have immunity to many attack forms. Use this type for any creature that was built or made rather than born or hatched.

The spell definition contradicts this definition of determining a monster’s type. For the purposes of determining its stats and qualities necessary for in-game use, use the creature type, consider it that creature, but the simulacrum itself still fits the bill to the Monster Manual's definition of an artificial construct.

In this regard, I don’t think the OP is wrong. What’s wrong is assuming that a simulacrum is merely “the creature type”, end of story.

Let’s examine an extrapolation that I’ve only discovered since deciding to offer my 2cents:

In the article’s expanded explanations, Artificial beings is a subheading listed under “Construct Traits”, and construct traits are listed as Special Qualities in the monster manual. It’s true that a simulacrum is an artificial being but not a construct and does not conform to the listed “construct traits”.
However, Undead are also mentioned as not being constructs, and the “undead traits” are similarly listed under Special Qualities. Whatever qualities a simulacrum possesses that are not derived from the duplicated creature type would sensibly fall into this category of Special Qualities as well. Even though “simulacrum” isn’t a defined type, it’s easy enough to use this precedent to categorize its limitations as a special quality as it's not part of the creatures normal (human) statistics. Special qualities that aren't supernatural or spell-like are lost upon being altered or polymorphed.

Summary: By RAW, and adhering the the precept of this thread, the limitation of a simulacrum is not due to some quality of it's human creature type, the source of this limitation being it's "unreal" part; this limitation is a quality that is neither normal nor magical, it is extraordinary. Extraordinary qualities are removed when a target is changed with alter self or polymorph.

That's still no guarantee that the DM would allow it, even by RAW the rules are mainly regarded as guidelines.

Happy rolling!