Question: I played a D&D 3.5 campaign years ago, and one PC was a druid. The player did a pretty awesome job as a spy thanks to the multiple divination spells, Wild Shape and especially A Thousand Faces:

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> [**A Thousand Faces (Su)**](http://www.d20srd.org/srd/classes/druid.htm#aThousandFaces)  
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>  At 13th level, a druid gains the ability to change her appearance at will, as if using the [*disguise self*](http://www.d20srd.org/srd/spells/disguiseSelf.htm) spell, but only while in her normal form. This affects the druid’s body but not her possessions. It is not an illusory effect, but a minor physical alteration of the druid’s appearance, within the limits described for the spell.
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I'm now planning to run a Pathfinder campaign (albeit with a custom world) with a lot of druids and I just don't understand how Thousand Faces fits for a "protector of the wild, lover of Nature" kind of guy (and I've never seen this ability used since this spy-druid), so I'm considering dropping A Thousand Faces.

Did you ever read something justifying this ability, in D&D or Pathfinder material or anywhere else, even real stories on druids?

**EDIT :** What bugs me is that I can't see proper use of this ability besides deception, and deception doesn't feel too "natural".

Answer: 
According to *Unearthed Arcana* (1985) for *Advanced Dungeons and Dragons*, “For druids of 16th level and above [… r]ather than spells, spell-like powers are acquired [including] the ability to alter his appearance at will. Appearance alteration is accomplished in 1 segment, with height and weight decrease/increase of 50% possible, apparent age from child to very old, and body and facial features of any human or humanoid sort. This alteration is non-magical, so it cannot be detected short of true seeing and the like” (17).

So in *Dungeons and Dragons 3.X* (and, subsequently, *Pathfinder*), this ability exists as a legacy of AD&D (and, probably, although I can't speak to it, 2nd Edition D&D). That answers why it exists *now*.

As to why it's existed for nearly 30 years, I vaguely remembered but couldn't find proof anywhere that Gygax believed Merlin was best represented by the druid class, and Merlin, according to sources as wide-ranging as Robert de Boron and Disney's *Sword and the Stone*, just changes shape a lot.

Theoretically, it's the idea that a lot of folks are much more willing to take advice from strangers than they are from folks they know (c.f. consultants), and such an ability makes the druid the ultimate advisor. If the only thing that penetrates his actually-physically-altered disguise is an AD&D *true seeing* spell, the druid can totally walk into the king's court in disguise, spout some "ancient prophecy" that says that the king shouldn't raise taxes or go to war or whatever, and depart, Batman-style, when he's finished, with none at court knowing that it was really the king's druid who delivered the message.

If you don't like the at-will *alter self* superpower, it should be replaced with something of equal utility. I suggest at-will *locate object* or *misdirection* or *augury* 3/day ('cause at-will *augury* is stupid), with this last possibly serving the same function as *alter self* in the theory detailed above.
This is not going to be a very detailed answer, but here are ideas.

It could allow you to visit cities without revealing your identity (with some different clothing if needed). This could be used to get a sense of people's behavior, especially if you're a well known druid in the region, in a prince-disguised-as-beggar-trick way.

It could also serve as a defense mechanism pretty much anywhere, again possibly complemented by a change of clothes. It's hard to look for or follow someone who changes appearance. 

In a sense, the above abilities are usually seen in fiction with a magic user (not just druids I think) turning into animals to observe discreetly or hide. Doing the same with humanoids seems just as valid.

And if you're the kind of druid actively protecting a natural location, you could turn into someone else to test the value of someone trespassing. The classic "will you help this old crone?" test.