Is there case law supporting the view that literary themes are protected by copyright?

Question

(I am not certain that "literary theme is the technically correct term: my question is contain in the body of the question). It is standard legal knowledge that copyright law protects expression and not ideas, that some element of creativity is required for a work to be protected, and that words and short phrases are not protected. It is also often widely believed that permission of the copyright holder is required to create a “related product”, such as a video game version of Star Trek, Harry Potter or James Bond (now partially in the public domain). Certain graphics associated with the protected work clearly require a license to use (I explicitly am not asking anything about trademark protection). If we set aside copying of graphic objects, and copying of non-minimal stretches of text, is there any case law evidence that supports the belief that any work “about” a protected work requires a copyright license? For example, does the case law tell me whether I can legally write a novel fully exploiting the ideas of the Man-Kzin Wars novels (a warlike feline spacefaring race etc.)?

An optional complication involves the putative non-copyrightability of words. The words “chmee; chrowl; kzinrret; kdaptist; sthondat; strakh; wtsai” are introduced in protected works – they are not words of English. They pass the sniff-test for creativity, but the US Copyright Office by policy declines to register individual words. However, presence of these words is clear evidence of copying of a protected work. It therefore may be important to distinguish infringement claims that involve the ideas of a protected work, and the additional copying of distinctive terminology.

Answer 1

A copyright protects particular expressions of ideas, not ideas themselves. So, general themes are not generally protected by copyright. Indeed, there is actually case law to the opposite effect, that prevents thematic elements particular to a genre from being granted copyright protection:

Scène à faire (French for "scene to be made" or "scene that must be done"; plural: scènes à faire) is a scene in a book or film which is almost obligatory for a book or film in that genre. In the U.S. it also refers to a principle in copyright law in which certain elements of a creative work are held to be not protected when they are mandated by or customary to the genre. . . .

The United States Court of Appeals for the Second Circuit interpreted the scènes à faire doctrine expansively to hold that a motion picture about the South Bronx would need to feature drunks, prostitutes, vermin, and derelict cars to be perceived as realistic, and therefore a later film that duplicated these features of an earlier film did not infringe. These elements are not protected by copyright, though specific sequences and compositions of them can be.

Citing Williams v. Crichton, 84 F.3d 581, 583 (2d Cir. 1996), commenting on Walker v. Time Life Films, Inc., 784 F.2d 44 (2d Cir.), cert. denied, 476 U.S. 1159 (1986).

Answer 2

whether I can legally write a novel fully exploiting the ideas of the Man-Kzin Wars novel

It depends on what you meant by "fully exploiting the idea." Quoting Nichols v. Universal Pictures Corporation, 45 F.2d 119 (2d Cir. 1930), the Second Circuit once said:

In Nichols, we enunciated what has now become known as the "abstractions" test for separating idea from expression:

Upon any work... a great number of patterns of increasing generality will fit equally well, as more and more of the incident is left out. The last may perhaps be no more than the most general statement of what the [work] is about, and at times might consist only of its title; but there is a point in this series of abstractions where they are no longer protected, since otherwise the [author] could prevent the use of his "ideas," to which, apart from their expression, his property is never extended.

Nichols, 45 F.2d at 121.

Computer Associates Intern., Inc. v. Altai, 982 F.2d 693 (2d Cir. 1992).

For example, copying plots may be infringing, according to Nichols:

We did not in Dymow v. Bolton, 11 F.2d 690, hold that a plagiarist was never liable for stealing a plot; that would have been flatly against our rulings in Dam v. Kirk La Shelle Co., 175 F. 902, 41 L.R.A. (N.S.) 1002, 20 Ann. Cas. 1173, and Stodart v. Mutual Film Co., 249 F. 513, affirming my decision in (D.C.) 249 F. 507; neither of which we meant to overrule.... [W]e do not doubt that two plays may correspond in plot closely enough for infringement.

Nichols.

Seems like Nichols is the line of cases that you are interested in.

Answer 3

Copyright prescribes when something is created and when it is a derivative work 17 U.S. Code § 101:

A work is “created” when it is fixed in a copy or phonorecord for the first time; where a work is prepared over a period of time, the portion of it that has been fixed at any particular time constitutes the work as of that time, and where the work has been prepared in different versions, each version constitutes a separate work.

A “derivative work” is a work based upon one or more preexisting works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which a work may be recast, transformed, or adapted. A work consisting of editorial revisions, annotations, elaborations, or other modifications which, as a whole, represent an original work of authorship, is a “derivative work”.

A work is “fixed” in a tangible medium of expression when its embodiment in a copy or phonorecord, by or under the authority of the author, is sufficiently permanent or stable to permit it to be perceived, reproduced, or otherwise communicated for a period of more than transitory duration. A work consisting of sounds, images, or both, that are being transmitted, is “fixed” for purposes of this title if a fixation of the work is being made simultaneously with its transmission.

The owner of a copyright has special rights under 17 U.S. Code $106, among them:

Subject to sections 107 through 122, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following: (2)to prepare derivative works based upon the copyrighted work;

So, where is the edge between a derivative work and an idea? Let's explore OP's examples:

• Harry Potter has a whole slew of background and stuff. Stories set in the Harry Potter Universe transform or adapt the given work and so are derivative works. Filmographic adaptions are, by the very definition in 17USC101, Derivative Works. And Ms. Rowling is known to litigate a lot to keep the number of unlicensed, notable derivative works down.
• Star Trek, analogous to Harry Potter, does create a world of fiction. Adapting it for a fanfiction is, technically, creating a derivative work. So technically the 5 paragraph story "A Trekkie's Tale" by Paula Smith in Menagerie #2 is a derivative work. However, unlike Ms. Rowling, ViacomCBS isn't the harshest litigator and they seem to have only rarely taken action against fanzines.
• James Bond, even if in the public in CANADA, it is still under copyright in the US till 2034 and after that is still under a Trademark that won't expire. Also, Ian Fleming Publications has lots of copyright on the films left and can claim with lots of details that something is derivative of the film, not the book. And they do litigate easily.

Now, back to the other example. The "Man-Kzin Wars" and lots of words from their language. Are they an expression of an idea or are they an unprotectable scene a fair? First of all, they are words without a meaning in normal English. Then, the wars is the title of a book series by Larry Niven. As such, the title and words imply strongly, that you want to write a derivative work of the Known Space universe, so you might want to try to acquire a license from Mr. Niven - he is very much still alive and has all copyright and the right to deny you writing in his universe. Only if you make our work never refer to anything from Niven's work, you'd get far enough and end in scenes a fair: for example, an intergalactic war between humans and a feline species (as the Kzinti from Niven's work are) is also the basis in WingCommander (humans vs. Kilrathi), and in general, a feline anthropomorphic species is pretty much scene a fair: StarTrek features Caitians as feline aliens, StarWars has about 25 feline species, some of them embroiled in the different wars and there are tons of others out there, and even putting them in direct conflict with the humans is scene a fair. However, the details of the war are the expression of this idea.