                  FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

MATTEL, INC., a Delaware               
corporation,
      Defendant-counter-claimant-
                           Appellee,
                  v.
MGA ENTERTAINMENT, INC.; MGA
ENTERTAINMENT (HK) LIMITED, a
Hong Kong Special Administrative
Region business entity; ISAAC
LARIAN, an individual,                      No. 09-55673
    Counter-defendants-Appellants,
CARTER BRYANT, an individual,                D.C. No.
                                           2:04-cv-09049-
        Plaintiff-counter-defendant,         SGL-RNB
CARLOS GUSTAVO MACHADO
GOMEZ, an individual; MGAE DE
MEXICO, S.R.L. DE C.V., a Mexico
business entity,
                 Counter-defendants,
ANNE WANG,
             Third-party-defendant,
OMNI 808 INVESTORS LLC,
                            Movant.
                                       




                            10523
10524          MATTEL v. MGA ENTERTAINMENT



CARTER BRYANT, an individual,          
       Plaintiff-counter-defendant-
                          Appellee,
MGA ENTERTAINMENT, INC.; MGA
ENTERTAINMENT (HK) LIMITED, a
Hong Kong Special Administrative
Region business entity; ISAAC
                                              No. 09-55812
LARIAN, an individual,
    Counter-defendants-Appellees,                D.C. No.
                 v.                       2:04-cv-09049-SGL-
                                                  RNB
MATTEL, INC., a Delaware
corporation,
                                               OPINION
      Defendant-counter-claimant-
                          Appellant,
CARLOS GUSTAVO MACHADO
GOMEZ, an individual; MGAE DE
MEXICO, S.R.L. DE C.V., a Mexico
business entity,
                 Counter-defendants.
                                       
        Appeal from the United States District Court
            for the Central District of California
        Stephen G. Larson, District Judge, Presiding

                 Argued and Submitted
          December 9, 2009—Pasadena, California

                     Filed July 22, 2010

 Before: Alex Kozinski, Chief Judge, Stephen S. Trott and
          Kim McLane Wardlaw, Circuit Judges.

             Opinion by Chief Judge Kozinski
10528         MATTEL v. MGA ENTERTAINMENT




                       COUNSEL

E. Joshua Rosenkranz (argued) and Lisa T. Simpson, Orrick,
Herrington & Sutcliffe LLP, New York, New York; Annette
L. Hurst and Warrington S. Parker III, Orrick, Herrington &
Sutcliffe LLP, San Francisco, California; and Thomas J.
Nolan and Jason D. Russell, Skadden, Arps, Slate, Meagher
& Flom LLP, Los Angeles, California, for the appellants.
               MATTEL v. MGA ENTERTAINMENT              10529
Daniel P. Collins (argued), Kelly M. Klaus, Aimee Feinberg
and Mark Yohalem, Munger, Tolles & Olson LLP, Los Ange-
les, California; and John B. Quinn, Susan R. Estrich, Michael
T. Zeller and B. Dylan Proctor, Quinn Emanuel Urquhart Oli-
ver & Hedges, LLP, Los Angeles, California, for the appellee.

Simon J. Frankel, Margaret D. Wilkinson and Steven D. Sas-
saman, Covington & Burling LLP, San Francisco, California;
Steven M. Freeman and Steven C. Sheinberg, Anti-
Defamation League, New York, New York; and Michelle N.
Deutchman, Anti-Defamation League, Los Angeles, Califor-
nia, for amici Anti-Defamation League et al.


                         OPINION

KOZINSKI, Chief Judge:

  Who owns Bratz?

                              I

   Barbie was the unrivaled queen of the fashion-doll market
throughout the latter half of the 20th Century. But 2001 saw
the introduction of Bratz, “The Girls With a Passion for Fash-
ion!” Unlike the relatively demure Barbie, the urban, multi-
ethnic and trendy Bratz dolls have attitude. This spunk struck
a chord, and Bratz became an overnight success. Mattel,
which produces Barbie, didn’t relish the competition. And it
was particularly unhappy when it learned that the man behind
Bratz was its own former employee, Carter Bryant.

   Bryant worked in the “Barbie Collectibles” department,
where he designed fashion and hair styles for high-end Barbie
dolls intended more for accumulation than for play. In August
2000, while he was still employed by Mattel, Bryant pitched
his idea for the Bratz line of dolls to two employees of MGA
10530             MATTEL v. MGA ENTERTAINMENT
Entertainment, one of Mattel’s competitors. Bryant was soon
called back to see Isaac Larian, the CEO of MGA. Bryant
brought some preliminary sketches, as well as a crude dummy
constructed out of a doll head from a Mattel bin, a Barbie
body and Ken (Barbie’s ex) boots. The Zoe, Lupe, Hallidae
and Jade dolls in Bryant’s drawings eventually made it to
market as Cloe, Yasmin, Sasha and Jade, the first generation
of Bratz dolls.

   Bryant signed a consulting agreement with MGA on Octo-
ber 4, 2000, though it was dated September 18. Bryant gave
Mattel two weeks’ notice on October 4 and continued work-
ing there until October 19. During this period, Bryant was
also working with MGA to develop Bratz, even creating a
preliminary Bratz sculpt.1 A sculpt is a mannequin-like plastic
doll body without skin coloring, face paint, hair or clothing.

   MGA kept Bryant’s involvement with the Bratz project
secret, but Mattel eventually found out. This led to a flurry of
lawsuits, which were consolidated in federal district court.
Proceedings below were divided into two phases. Phase 1
dealt with claims relating to the ownership of Bratz; Phase 2
is pending and will deal with the remaining claims. This is an
interlocutory appeal from the equitable orders entered at the
conclusion of Phase 1.

   During Phase 1, Mattel argued that Bryant violated his
employment agreement by going to MGA with his Bratz idea
instead of disclosing and assigning it to Mattel. Mattel
claimed it was the rightful owner of Bryant’s preliminary
sketches and sculpt, which it argued MGA’s subsequent Bratz
dolls infringed. And it asserted that MGA wrongfully
acquired the ideas for the names “Bratz” and “Jade,” so the
Bratz trademarks should be transferred from MGA to Mattel.
  1
   The sculpt was actually crafted by a freelance sculptor with input from
Bryant. The parties disputed below whether Bryant “created” it, and the
jury found that Bryant did. This finding is not challenged on appeal.
                  MATTEL v. MGA ENTERTAINMENT                      10531
   Mattel won virtually every point below. The jury found that
Bryant thought of the “Bratz” and “Jade” names, and created
the preliminary sketches and sculpt, while he was employed
by Mattel. It found that MGA committed three state-law vio-
lations relating to Bryant’s involvement with Bratz. And it
issued a general verdict finding MGA liable for infringing
Mattel’s copyrights in Bryant’s preliminary Bratz works. Mat-
tel sought more than $1 billion in copyright damages but the
jury awarded Mattel only $10 million, or about 1% of that
amount, perhaps because it found only a small portion of the
Bratz dolls infringing. See p.10537 infra.

   The district court entered equitable relief based on the
jury’s findings. As to the state-law violations, the district
court imposed a constructive trust over all trademarks includ-
ing the terms “Bratz” and “Jade,” essentially transferring the
Bratz trademark portfolio to Mattel.2 The transfer prohibited
MGA from marketing any Bratz-branded product, such as
Bratz dolls (Bratz, Bratz Boyz, Lil’ Bratz, Bratz Lil’ Angelz,
Bratz Petz, Bratz Babyz, Itsy Bitsy Bratz, etc.), doll accesso-
ries (Bratz World House, Bratz Cowgirlz Stable, Bratz Spring
Break Pool, Bratz Babyz Ponyz Buggy Blitz, etc.), video
games (“Bratz: Girlz Really Rock,” “Bratz: Forever Dia-
mondz,” “Bratz: Rock Angelz,” etc.) and Bratz the movie.

   As to the copyright claim, the district court issued an
injunction prohibiting MGA from producing or marketing vir-
tually every Bratz female fashion doll, as well as any future
dolls substantially similar to Mattel’s copyrighted Bratz
works. The injunction covered not just the original four dolls,
but also subsequent generations (e.g., “Bratz Slumber Party
Sasha” and “Bratz Girlfriendz Nite Out Cloe”) and other doll
  2
   Based on the finding that MGA wrongfully acquired the ideas for the
names “Bratz” and “Jade,” the district court also entered a UCL injunction
and a declaratory judgment concerning MGA’s right to the Bratz trade-
marks. For simplicity, we will refer only to the constructive trust to
describe all equitable relief.
10532           MATTEL v. MGA ENTERTAINMENT
characters (e.g., “Bratz Play Sportz Lilee” and “Bratz Twins
Phoebe and Roxxi”).

  In effect, Barbie captured the Bratz. The Bratz appeal.

                               II

    [1] A constructive trust is an equitable remedy that com-
pels the transfer of wrongfully held property to its rightful
owner. Communist Party of U.S. v. 522 Valencia, Inc., 41 Cal.
Rptr. 2d 618, 623 (Cal. Ct. App. 1995); see also Cal. Civ.
Code § 2223 (“One who wrongfully detains a thing is an
involuntary trustee thereof, for the benefit of the owner.”). A
plaintiff seeking imposition of a constructive trust must show:
(1) the existence of a res (property or some interest in prop-
erty); (2) the right to that res; and (3) the wrongful acquisition
or detention of the res by another party who is not entitled to
it. Communist Party, 41 Cal. Rptr. 2d at 623-24.

   Prior to trial, the district court held that Bryant’s employ-
ment agreement assigned his ideas to Mattel, and so instructed
the jury. What was left for the jury to decide was which ideas
Bryant came up with during his time with Mattel. It found that
Bryant thought of the names “Bratz” and “Jade” while he was
employed by Mattel, and that MGA committed several state-
law violations by interfering with Bryant’s agreement as well
as aiding and abetting its breach. After trial, the district court
imposed a constructive trust over all Bratz-related trademarks.
We review that decision for abuse of discretion. See GHK
Assocs. v. Mayer Group, Inc., 274 Cal. Rptr. 168, 182 (Cal.
Ct. App. 1990).

                               A.

   [2] A constructive trust would be appropriate only if Bry-
ant assigned his ideas for “Bratz” and “Jade” to Mattel in the
first place. Whether he did turns on the interpretation of Bry-
ant’s 1999 employment agreement, which provides: “I agree
                 MATTEL v. MGA ENTERTAINMENT                   10533
to communicate to the Company as promptly and fully as
practicable all inventions (as defined below) conceived or
reduced to practice by me (alone or jointly by others) at any
time during my employment by the Company. I hereby assign
to the Company . . . all my right, title and interest in such
inventions, and all my right, title and interest in any patents,
copyrights, patent applications or copyright applications
based thereon.” (Emphasis added.) The contract specifies that
“the term ‘inventions’ includes, but is not limited to, all dis-
coveries, improvements, processes, developments, designs,
know-how, data computer programs and formulae, whether
patentable or unpatentable.” The district court held that the
agreement assigned Bryant’s ideas to Mattel, even though
ideas weren’t included on that list or mentioned anywhere
else in the contract.3 We review the district court’s construc-
tion of the agreement de novo. See L.K. Comstock & Co. v.
United Eng’rs & Constructors Inc., 880 F.2d 219, 221 (9th
Cir. 1989).

   Mattel points out that the list of examples of what consti-
tutes an invention is illustrative rather than exclusive. Ideas,
however, are markedly different from most of the listed exam-
ples. Cf. People ex rel. Lungren v. Superior Ct., 926 P.2d
1042, 1057 (Cal. 1996) (courts avoid constructions that would
make “a particular item in a series . . . markedly dissimilar to
other items on the same list”). Designs, processes, computer
programs and formulae are concrete, unlike ideas, which are
ephemeral and often reflect bursts of inspiration that exist
only in the mind. On the other hand, the agreement also lists
less tangible inventions such as “know-how” and “discover-
ies.” And Bryant may have conveyed rights in innovations
that were not embodied in a tangible form by assigning inven-
tions he “conceived” as well as those he reduced to practice.
  3
    Contrary to Mattel’s argument, MGA adequately preserved its objec-
tions to this ruling.
10534           MATTEL v. MGA ENTERTAINMENT
   [3] We conclude that the agreement could be interpreted to
cover ideas, but the text doesn’t compel that reading. The dis-
trict court thus erred in holding that the agreement, by its
terms, clearly covered ideas. Had the district court recognized
the ambiguity, it might have evaluated whether it could be
resolved by extrinsic evidence. See Wolf v. Superior Court, 8
Cal. Rptr. 3d 649, 655-56 (Cal. Ct. App. 2004). At various
stages of litigation, the parties introduced such evidence sup-
porting their respective interpretations of “inventions.” Con-
tracts Mattel drafted for other employees, for example,
expressly assigned their “ideas” as well as their “inventions.”
This tends to show that the term “inventions” alone doesn’t
include ideas. On the other hand, a Mattel executive claimed
during her deposition that it was common knowledge in the
design industry that terms like “invention” and “design” did
include employee ideas. Because the district court concluded
that the language of the contract was clear, it didn’t consider
the extrinsic evidence the parties presented. Even if it had, it
may not have been able to resolve the meaning of “inven-
tions.” If the meaning turns in part on the credibility of con-
flicting extrinsic evidence, a properly instructed jury should
have decided the issue. See Morey v. Vannucci, 75 Cal. Rptr.
2d 573, 579 (Cal. Ct. App. 1998). Because we must vacate the
constructive trust in any event, for reasons explained below,
this is a matter the district court can take up on remand.

                              B.

  The very broad constructive trust the district court imposed
must be vacated regardless of whether Bryant’s employment
agreement assigned his ideas to Mattel. Even assuming that it
did, and that MGA therefore misappropriated the names
“Bratz” and “Jade,” the value of the trademarks the company
eventually acquired for the entire Bratz line was significantly
greater because of MGA’s own development efforts, market-
ing and investment. The district court nonetheless transferred
MGA’s entire Bratz trademark portfolio to Mattel on the
ground that the “enhancement of value [of the property held
                MATTEL v. MGA ENTERTAINMENT                10535
in trust] is given to the beneficiary of the constructive trust.”
As a result, Mattel acquired the fruit of MGA’s hard work,
and not just the appreciation in value of the ideas Mattel
claims it owns.

   [4] In general, “[t]he beneficiary of the constructive trust
is entitled to enhancement in value of the trust property.”
Haskel Eng’g & Supply Co. v. Hartford Accident & Indem.
Co., 144 Cal. Rptr. 189, 193 (Cal. Ct. App. 1978). This is so
“not because [the beneficiary] has a substantive right to [the
enhancement] but rather to prevent unjust enrichment of the
wrongdoer-constructive trustee.” Id. Thus, a person who
fraudulently acquired a house worth $100,000 in 2000 that
appreciates to $200,000 by 2010 because of a strong real
estate market can’t complain when the rightful owner takes
the benefit of the $100,000 increase. “[I]t is simple equity that
a wrongdoer should disgorge his fraudulent enrichment.”
Janigan v. Taylor, 344 F.2d 781, 786 (1st Cir. 1965).

   [5] This principle has the greatest force where the appreci-
ation of the property is due to external factors rather than the
efforts of the wrongful acquisitor. Id. at 787. “When the
defendant profits from the wrong, it is necessary to identify
the profits and to recapture them without capturing the fruits
of the defendant’s own labors or legitimate efforts.” Dan B.
Dobbs, Dobbs Law of Remedies: Damages-Equity-Restitution
§ 6.6(3) (2d ed. 1993). This is because “the aim of restitution
has been to avoid taking the defendant’s blood along with the
pound of flesh.” Id. § 6.6(3) n.4. A constructive trust is there-
fore “not appropriate to every case because it can overdo the
job.” Id. § 4.3(2).

   [6] When the value of the property held in trust increases
significantly because of a defendant’s efforts, a constructive
trust that passes on the profit of the defendant’s labor to the
plaintiff usually goes too far. For example, “[i]f an artist
acquired paints by fraud and used them in producing a valu-
able portrait we would not suggest that the defrauded party
10536           MATTEL v. MGA ENTERTAINMENT
would be entitled to the portrait, or to the proceeds of its
sale.” Janigan, 344 F.2d at 787. Even assuming that MGA
took some ideas wrongfully, it added tremendous value by
turning the ideas into products and, eventually, a popular and
highly profitable brand. The value added by MGA’s hard
work and creativity dwarfs the value of the original ideas Bry-
ant brought with him, even recognizing the significance of
those ideas. We infer that the jury made much the same judg-
ment when it awarded Mattel only a small fraction of the
more than $1 billion in interest-adjusted profit MGA made
from the brand.

   From the ideas for the names “Bratz” and “Jade,” MGA
created not only the first generation of Bratz dolls (Cloe,
Yasmin, Sasha and Jade), but also many other Bratz charac-
ters (Ciara, Dana, Diona, Felicia, Fianna and so on), as well
as subsequent generations of the original four dolls (“Bratz
Flower Girlz Cloe,” “Bratz on Ice Doll Yasmin,” etc.). MGA
also generated other doll lines, such as the Bratz Boyz, Bratz
Petz and Bratz Babyz. And it made a variety of Bratz doll
accessories, along with several Bratz video games and a
movie. These efforts significantly raised the profile of the
Bratz brand and increased the value of the Bratz trademarks.

   [7] It is not equitable to transfer this billion dollar brand—
the value of which is overwhelmingly the result of MGA’s
legitimate efforts—because it may have started with two mis-
appropriated names. The district court’s imposition of a con-
structive trust forcing MGA to hand over its sweat equity was
an abuse of discretion and must be vacated.

                              III

  [8] Mattel also claimed ownership of Bryant’s preliminary
Bratz drawings and sculpt under Bryant’s employment agree-
ment, and that MGA’s subsequent Bratz dolls infringed its
copyrights in those works. The drawings and sculpt clearly
were “inventions” as that term is defined in Bryant’s employ-
                  MATTEL v. MGA ENTERTAINMENT                     10537
ment agreement with Mattel. However, MGA argued that the
employment agreement didn’t assign the items because Bry-
ant created them outside the scope of his employment at Mat-
tel, on his own time. At summary judgment, the district court
held that the agreement assigned inventions even if they were
not made during working hours, so long as they were created
during the time period Bryant was employed by Mattel. So
instructed, the jury found that Bryant made the drawings and
sculpt while he was employed by Mattel, and the agreement
therefore assigned them to Mattel.4 The jury was not asked to
find whether Bryant made the drawings and sculpt during
Mattel work hours, and it’s unclear whether the record con-
tained any evidence on this point.

   Once Mattel established ownership of Bryant’s preliminary
sketches and sculpt, it pursued a copyright claim against
MGA. The district court instructed the jury that any “substan-
tially similar” Bratz doll infringed Mattel’s copyrights in the
sketches and sculpt. During deliberations, the jury sent the
judge a note asking if it could find infringement as to the first
generation of Bratz dolls and no others. The judge said it
could. The jury returned a general verdict finding MGA liable
for copyright infringement, but awarded Mattel only $10 mil-
lion in damages, a tiny fraction of the more than $1 billion to
which Mattel claimed it was entitled. The district court
thought it unclear which Bratz dolls, or how many dolls, the
jury thought infringing, so it made its own infringement find-
ings in determining whether Mattel was entitled to equitable
relief. The district court found the vast majority of Bratz dolls
infringing and enjoined MGA from producing them or any
other substantially similar dolls.
  4
    The jury also found that Bryant created the dummy doll, see p.10530
supra, while he was at Mattel. The dummy was thrown away long before
this litigation ensued, and was so crude that no copyright claim is based
on it.
10538              MATTEL v. MGA ENTERTAINMENT
                                     A.

   Bryant’s 1999 employment agreement assigns to Mattel
inventions created “at any time during my employment by the
Company.”5 MGA argues that “at any time during my
employment” covers only works created within the scope of
Bryant’s employment, not those created on his own time and
outside of his duties at Mattel. Bryant wasn’t tasked with cre-
ating new doll lines there; he designed fashions and hair styles
for Barbie Collectibles. MGA thus argues that Bryant created
the Bratz designs and came up with the names “Bratz” and
“Jade” outside the scope of his employment, and that he
therefore owns the work.6

   The district court disagreed, holding at summary judgment
that the agreement assigned to Mattel “any doll or doll fash-
ions [Bryant] designed during the period of his employment
with Mattel.” It was therefore irrelevant “whether Bryant
worked on [Bratz] on his own time [or] during his working
hours at Mattel.” We again review the district court’s con-
struction of the contract de novo. See L.K. Comstock, 880
F.2d at 221.

  [9] The phrase “at any time during my employment” is
ambiguous. It could easily refer to the entire calendar period
Bryant worked for Mattel, including nights and weekends.
  5
     The agreement excepts inventions that “qualif[y] under the provision
of Section 2870 of the California Labor Code[, which] provides that the
requirement to assign ‘shall not apply to an invention that the employee
developed entirely on his or her own time without using the employer’s
equipment, supplies, facilities or trade secret information except for those
inventions that either (1) relate at the time of conception or reduction to
practice of the invention to the employer’s business . . . or (2) result from
any work performed by the employee for the employer.’ ”
   6
     It won’t matter whether Bryant came up with the ideas in the course
of employment if the district court or a properly instructed jury determines
that the agreement didn’t assign ideas in the first place. See Part II.A
supra.
                  MATTEL v. MGA ENTERTAINMENT                   10539
But it can also be read more narrowly to encompass only
those inventions created during work hours (“during my
employment”), possibly including lunch and coffee breaks
(“at any time”).7 Extrinsic evidence doesn’t resolve the
ambiguity. For example, an employee testified that it was
“common knowledge that a lot of people were moonlighting
and doing other work,” which wasn’t a problem so long as it
was done on “their own time,” and at “their own house.” She
agreed when asked, “Was it your understanding that if you
designed dolls when you were at home at night that you
owned them?” However, another employee testified, “Every-
thing I did for Mattel belonged to Mattel. Actually, everything
I did while I was working for Mattel belonged to Mattel.”

   [10] Because the agreement’s language is ambiguous and
some extrinsic evidence supports each party’s reading, the
district court erred by granting summary judgment to Mattel
on this issue and holding that the agreement clearly assigned
works made outside the scope of Bryant’s employment. See
City of Hope Nat’l Med. Ctr., 181 P.3d at 156. The issue
should have been submitted to the jury, which could then
have been instructed to determine (1) whether Bryant’s agree-
ment assigned works created outside the scope of his employ-
ment at Mattel, and (2) whether Bryant’s creation of the Bratz
sketches and sculpt was outside the scope of his employment.

                                  B.

  The district court’s error in construing the employment
agreement is sufficient to vacate the copyright injunction. On
  7
   Mattel argues that because employers are already considered the
authors of works made for hire under the Copyright Act, 17 U.S.C.
§ 201(b), the agreement must cover works made outside the scope of
employment. Otherwise, employees would be assigning to Mattel works
the company already owns. But the contract provides Mattel additional
rights by covering more than just copyrightable works. The contract can
also be enforced in state court, whereas Copyright Act claims must be
heard in federal court.
10540           MATTEL v. MGA ENTERTAINMENT
remand, Mattel might well convince a properly instructed jury
that the agreement assigns works created outside the scope of
employment, or that Bryant’s preliminary Bratz sketches and
sculpt were created within the scope of his employment at
Mattel. The district court would then once again have to
decide whether to grant a copyright injunction. We therefore
believe it prudent to address MGA’s appeal of the district
court’s copyright rulings.

   [11] Mattel argued that MGA’s Bratz dolls infringed its
copyrights in the sketches and sculpt. To win its copyright
claim, Mattel had to establish three things. First, Mattel had
to prove that it owned copyrights in the sketches and sculpt
(it did). Second, it had to show that MGA had access to the
sketches and sculpt (obviously). Third, it had to establish that
MGA’s dolls infringe the sketches and sculpt (the kicker). See
Aliotti v. R. Dakin & Co., 831 F.2d 898, 900 (9th Cir. 1987).

   [12] Assuming that Mattel owns Bryant’s preliminary
drawings and sculpt, its copyrights in the works would cover
only its particular expression of the bratty-doll idea, not the
idea itself. See Herbert Rosenthal Jewelry Corp. v. Kal-
pakian, 446 F.2d 738, 742 (9th Cir. 1971). Otherwise, the first
person to express any idea would have a monopoly over it.
Degas can’t prohibit other artists from painting ballerinas, and
Charlaine Harris can’t stop Stephenie Meyer from publishing
Twilight just because Sookie came first. Similarly, MGA was
free to look at Bryant’s sketches and say, “Good idea! We
want to create bratty dolls too.”

   [13] Mattel, of course, argues that MGA went beyond this
by copying Bryant’s unique expression of bratty dolls, not just
the idea. To distinguish between permissible lifting of ideas
and impermissible copying of expression, we have developed
a two-part “extrinsic/intrinsic” test. See Apple Computer, Inc.
v. Microsoft Corp., 35 F.3d 1435, 1442 (9th Cir. 1994). At the
initial “extrinsic” stage, we examine the similarities between
the copyrighted and challenged works and then determine
                MATTEL v. MGA ENTERTAINMENT                10541
whether the similar elements are protectable or unprotectable.
See id. at 1442-43. For example, ideas, scenes a faire (stan-
dard features) and unoriginal components aren’t protectable.
Id. at 1143-45. When the unprotectable elements are “filtered”
out, what’s left is an author’s particular expression of an idea,
which most definitely is protectable. Id.

   [14] Given that others may freely copy a work’s ideas (and
other unprotectable elements), we start by determining the
breadth of the possible expression of those ideas. If there’s a
wide range of expression (for example, there are gazillions of
ways to make an aliens-attack movie), then copyright protec-
tion is “broad” and a work will infringe if it’s “substantially
similar” to the copyrighted work. See id. at 1439, 1146-47. If
there’s only a narrow range of expression (for example, there
are only so many ways to paint a red bouncy ball on blank
canvas), then copyright protection is “thin” and a work must
be “virtually identical” to infringe. See id.; Satava v. Lowry,
323 F.3d 805, 812 (9th Cir. 2003) (glass-in-glass jellyfish
sculpture only entitled to thin protection against virtually
identical copying due to the narrow range of expression).

   The standard for infringement—substantially similar or vir-
tually identical—determined at the “extrinsic” stage is applied
at the “intrinsic” stage. See Apple Computer, 35 F.3d at 1443.
There we ask, most often of juries, whether an ordinary rea-
sonable observer would consider the copyrighted and chal-
lenged works substantially similar (or virtually identical). See
id. at 1442. If the answer is yes, then the challenged work is
infringing.

  The district court conducted an extrinsic analysis and deter-
mined that the following elements of Bryant’s sketches and
sculpt were non-protectable:

    1.   The resemblance or similarity to human form
         and human physiology.
10542           MATTEL v. MGA ENTERTAINMENT
    2.   The mere presence of hair, heads, two eyes, eye-
         brows, lips, nose, chin, mouth, and other fea-
         tures that track human anatomy and physiology.

    3.   Human clothes, shoes, and accessories.

    4.   Age, race, ethnicity, and “urban” or “rural”
         appearances.

    5.   Common or standard anatomical features rela-
         tive to others (doll nose and relatively thin,
         small bodies).

    6.   Scenes a faire, or common or standard treat-
         ments of the subject matter.

It found that the following elements were protectable:

    1.   Particularized, synergistic compilation and
         expression of the human form and anatomy that
         expresses a unique style and conveys a distinct
         look or attitude.

    2.   Particularized expression of the doll’s head, lips,
         eyes, eyebrows, eye features, nose, chin, hair
         style and breasts, including the accentuation or
         exaggeration of certain anatomical features rela-
         tive to others (doll lips, eyes, eyebrows, and eye
         features) and de-emphasis of certain anatomical
         features relative to others (doll nose and thin,
         small doll bodies).

    3.   Particularized, non-functional doll clothes, doll
         shoes, and doll accessories that express aggres-
         sive, contemporary, youthful style.

Based on this determination, the district court decided that
“substantial similarity” is the appropriate test for infringe-
                   MATTEL v. MGA ENTERTAINMENT                      10543
ment. And, in determining whether Mattel was entitled to
equitable relief, it found that the two Bratz sculpts and the
overwhelming majority of the Bratz female fashion dolls were
substantially similar to Mattel’s copyrighted works. The dis-
trict court therefore entered an injunction prohibiting MGA
from producing the infringing dolls or any future substantially
similar dolls. We review de novo the district court’s determi-
nation as to the scope of copyright protection. See Ets-Hokin
v. Skyy Spirits, Inc., 225 F.3d 1068, 1073 (9th Cir. 2000).

   1. Doll Sculpt. The district court enjoined MGA from mar-
keting or producing any doll that incorporates the “core Bratz
fashion doll production sculpt” or the “Bratz Movie sculpt”
because it held they were substantially similar to Bryant’s
preliminary sculpt.8 By adopting the “substantially similar”
standard, the district court afforded Bryant’s sculpt broad
copyright protection. See pp.10540-41 supra. MGA argues
that the district court should have given Bryant’s preliminary
sculpt only thin protection against virtually identical works.

   [15] In order to determine the scope of protection for the
sculpt, we must first filter out any unprotectable elements.
Producing small plastic dolls that resemble young females is
a staple of the fashion doll market. To this basic concept, the
Bratz dolls add exaggerated features, such as an oversized
head and feet. But many fashion dolls have exaggerated
features—take the oversized heads of the Blythe dolls and My
Scene Barbies as examples. Moreover, women have often
been depicted with exaggerated proportions similar to those of
the Bratz dolls—from Betty Boop to characters in Japanese
anime and Steve Madden ads. The concept of depicting a
young, fashion-forward female with exaggerated features,
  8
    The district court’s analysis was brief, so we must infer this finding.
It’s possible that the district court also thought MGA’s two sculpts were
substantially similar to some of Bryant’s sketches of doll bodies. Even if
this were so, it wouldn’t change our analysis because the sketches of doll
bodies would be entitled to no more protection here than Bryant’s sculpt.
10544           MATTEL v. MGA ENTERTAINMENT
including an oversized head and feet, is therefore unoriginal
as well as an unprotectable idea. Cf. Herbert Rosenthal, 446
F.2d at 742 (“We think the production of jeweled bee pins is
a larger private preserve than Congress intended to be set
aside . . . . A jeweled bee pin is therefore an ‘idea’ that defen-
dants were free to copy.”).

   Mattel argues that the sculpt was entitled to broad protec-
tion because there are many ways one can depict an exagger-
ated human figure. It’s true that there’s a broad range of
expression for bodies with exaggerated features: One could
make a fashion doll with a large nose instead of a small one,
or a potbelly instead of a narrow waist. But there’s not a big
market for fashion dolls that look like Patty and Selma Bou-
vier. Little girls buy fashion dolls with idealized proportions
—which means slightly larger heads, eyes and lips; slightly
smaller noses and waists; and slightly longer limbs than those
that appear routinely in nature. But these features can be
exaggerated only so much: Make the head too large or the
waist too small and the doll becomes freakish, not idealized.

   [16] The expression of an attractive young, female fashion
doll with exaggerated proportions is thus highly constrained.
Cf. Data East USA, Inc. v. EPYX, Inc., 862 F.2d 204, 209 (9th
Cir. 1988) (“Because of these constraints, karate is not sus-
ceptible of a wholly fanciful presentation.”). Because of the
narrow range of expression, the preliminary sculpt is entitled
to only thin copyright protection against virtually identical
copying. Cf. Ets-Hokin v. Skyy Spirits Inc., 323 F.3d 763, 766
(9th Cir. 2003) (photo of vodka bottle merits only thin protec-
tion because of limited range of expression); Satava, 323 F.3d
at 812 (similar). The district court erred in affording broad
protection against works substantially similar to the sculpt.

   2. Bratz Sketches. The district court also enjoined MGA
from marketing or producing nearly every Bratz female fash-
ion doll—not just the first generation of dolls, but also subse-
quent dolls like “Bratz Nighty-Nite Yasmin” and “Bratz
                   MATTEL v. MGA ENTERTAINMENT                        10545
Campfire Felicia”—because it held they were substantially
similar to Bryant’s preliminary sketches.9 MGA argues that
the district court erred in failing to filter out the unprotectable
elements of the dolls and by applying the substantial similar-
ity standard.10

   [17] Unlike the limited range of expression for the sculpt,
there’s a wide range of expression for complete young, hip
female fashion dolls with exaggerated features. Designers
may vary the face paint, hair color and style, and the clothing
and accessories, on top of making minor variations to the
sculpt. One doll might have brown eyes with bronze
eyeshadow, wavy auburn hair, leather boots, a blue plaid mini
matched with a black button-down, silver knot earrings and a
barrel bag. Another might have green eyes with pink
eyeshadow, brown hair in a messy bun, gold wedges, dark
skinny jeans matched with a purple halter, a turquoise cuff
and a clutch, along with a slightly different body and facial struc-
ture.11 See JCW Invs. v. Novelty, Inc., 482 F.3d 910, 917 (7th
  9
    Infringement can occur even though the copyrighted work is done in
a different medium than the challenged work. Meshwerks, Inc. v. Toyota
Motor Sales U.S.A., Inc., 528 F.3d 1258, 1267-68 (10th Cir. 2008); see
Blanch v. Koons, 467 F.3d 244, 252 (2d Cir. 2006).
   10
      Contrary to Mattel’s argument, MGA’s opening brief adequately pre-
served its objections to the district court’s decision.
   11
      MGA argues that doll clothes aren’t entitled to copyright protection.
Copyright law doesn’t protect “useful articles” that have an “intrinsic utili-
tarian function” apart from their expression or appearance. See 17 U.S.C.
§§ 101, 102(a)(5). Human clothing is considered utilitarian and unprotect-
able. See Poe v. Missing Persons, 745 F.2d 1238, 1242 (9th Cir. 1984).
However, articles that are intended only to portray the appearance of
clothing are protectable. Id. Dolls don’t feel cold or worry about modesty.
The fashions they wear have no utilitarian function. Cf. Masquerade Nov-
elty v. Unique Indus., 912 F.2d 663, 670-71 (3d Cir. 1990) (animal nose
masks have no utilitarian function apart from portraying appearance of
animal nose); Gay Toys, Inc. v. Buddy L Corp., 703 F.2d 970, 973 (6th
Cir. 1983) (toy airplane merely portrays appearance of actual airplane and
has no utilitarian function). Even if we were to defer to the letter from the
Copyright Office saying that doll clothing isn’t protected, as MGA argues
we should, the letter’s interpretation is obviously wrong.
10546           MATTEL v. MGA ENTERTAINMENT
Cir. 2007) (“Novelty could have created another plush doll of
a middle-aged farting man that would seem nothing like Fred.
He could, for example, have a blond mullet and wear flannel,
have a nose that is drawn on rather than protruding substan-
tially from the rest of the head, be standing rather than
ensconced in an armchair, and be wearing shorts rather than
blue pants.”). The district court didn’t err in affording the doll
sketches broad copyright protection against substantially simi-
lar works.

   [18] The district court did err, however, in failing to filter
out all the unprotectable elements of Bryant’s sketches. The
only unprotectable elements the district court identified were:
(1) the dolls’ resemblance to humans; (2) the presence of hair,
head, two eyes and other human features; (3) human clothes,
shoes and accessories; (4) age, race, ethnicity and “urban” or
“rural” appearances; (5) standard features relative to others
(like a thin body); and (6) other standard treatments of the
subject matter. And it reasoned that the doll’s
“[p]articularized, synergistic compilation and expression of
the human form and anatomy that expresses a unique style
and conveys a distinct look or attitude” is protectable, along
with the doll fashions that expressed an “aggressive, contem-
porary, youthful style.” But Mattel can’t claim a monopoly
over fashion dolls with a bratty look or attitude, or dolls sport-
ing trendy clothing—these are all unprotectable ideas.

   [19] This error was significant. Although substantial simi-
larity was the appropriate standard, a finding of substantial
similarity between two works can’t be based on similarities in
unprotectable elements. See Data East, 862 F.2d at 209 (clear
error for district court to determine substantial similarity
existed based on unprotectable elements). When works of art
share an idea, they’ll often be “similar” in the layman’s sense
of the term. For example, the stuffed, cuddly dinosaurs at
issue in Aliotti v. R. Dakin & Company, 831 F.2d at 901, were
similar in that they were all stuffed, cuddly dinosaurs—but
that’s not the sort of similarity we look for in copyright law.
                MATTEL v. MGA ENTERTAINMENT               10547
“Substantial similarity” for copyright infringement requires a
similarity of expression, not ideas. See id. The key question
always is: Are the works substantially similar beyond the fact
that they depict the same idea?

   [20] MGA’s Bratz dolls can’t be considered substantially
similar to Bryant’s preliminary sketches simply because the
dolls and sketches depict young, stylish girls with big heads
and an attitude. Yet this appears to be how the district court
reasoned:

    Especially important to the Court’s [substantial simi-
    larity finding] is the consistency of the particularized
    expression of the dolls’ heads, lips, eyes, eyebrows,
    eye features, noses, as well as the particularized
    expression of certain anatomical features relative to
    others . . . and de-emphasis of certain anatomical
    features (most notably the minimalized doll nose and
    thin, small doll bodies). Also important to the Court
    is the particularized, synergistic compilation and
    expression of the human form and anatomy that
    quite clearly expresses a unique style and conveys a
    distinct look or attitude . . . .

It might have been reasonable to hold that some of the Bratz
dolls were substantially similar to Bryant’s sketches, espe-
cially those in the first generation. But we fail to see how the
district court could have found the vast majority of Bratz
dolls, such as “Bratz Funk ‘N’ Glow Jade” or “Bratz Wild
Wild West Fianna,” substantially similar—even though their
fashions and hair styles are nothing like anything Bryant drew
—unless it was relying on similarities in ideas.

                             ***

   Bryant’s employment agreement may not have assigned his
ideas for the names “Bratz” and “Jade” to Mattel at all, and
the district court erred by holding that it did so unambigu-
10548              MATTEL v. MGA ENTERTAINMENT
ously. Even if Bryant did assign his ideas, the district court
abused its discretion in transferring the entire Bratz trademark
portfolio to Mattel. We therefore vacate the constructive trust,
UCL injunction and declaratory judgment concerning Mat-
tel’s rights to the Bratz trademarks. The district court may
impose a narrower constructive trust on remand only if there’s
a proper determination that Mattel owns Bryant’s ideas.

   [21] The district court also erred in holding, at summary
judgment, that the employment agreement assigned works
created outside the scope of Bryant’s employment. We there-
fore vacate the copyright injunction. On remand, Mattel will
have to convince a jury that the agreement assigned Bryant’s
preliminary sketches and sculpt, either because the agreement
assigns works made outside the scope of employment or
because these works weren’t made outside of Bryant’s
employment. And, in order to justify a copyright injunction,
Mattel will have to show that the Bratz sculpts are virtually
identical to Bryant’s preliminary sculpt, or that the Bratz dolls
are substantially similar to Bryant’s sketches disregarding
similarities in unprotectable ideas.

   Nothing we say here precludes the entry of equitable relief
based on appropriate findings.12 Because several of the errors
we have identified appeared in the jury instructions, it’s likely
that a significant portion—if not all—of the jury verdict and
damage award should be vacated, and the entire case will
   12
      We decline to address MGA’s appeal of the mistrial order and Mat-
tel’s cross-appeal of the attorney-client privilege finding. These issues are
likely moot, and their resolution is unnecessary to dispose of this interloc-
utory appeal. Our jurisdiction over them is also doubtful. See Poulos v.
Caesars World, Inc., 379 F.3d 654, 668-70 (9th Cir. 2004). We also
decline to address MGA’s appeal of the district court’s decisions concern-
ing the three alleged state-law violations, which Mattel argues show that
MGA wrongfully acquired the ideas for the names “Bratz” and “Jade.”
We’ve found that the district court didn’t properly analyze whether Mattel
owns Bryant’s ideas under his contract, so it’s premature to try to deter-
mine whether MGA’s acquisition of them was wrongful.
               MATTEL v. MGA ENTERTAINMENT              10549
probably need to be retried. We express no opinion on this
issue here, except to say that any further proceedings must be
consistent with our decision.

   America thrives on competition; Barbie, the all-American
girl, will too.

  EQUITABLE RELIEF VACATED. Each party shall
bear its own costs.
