What is considered a derivative work?
<p>US Copyright law defines &quot;derivative work&quot;:</p>
<blockquote>
<p>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”.</p>
</blockquote>
<p>I'm not sure if the examples below can be considered derivative works as well:</p>
<ul>
<li>an academic paper that cites or refers to other papers</li>
<li>a discussion thread on Internet (or each comment or reply on it) about a work</li>
<li>a fanart or a fanfiction</li>
<li>metadata</li>
<li>a review or a criticism</li>
<li>a work inspired by other works</li>
</ul>
<p>They don't quite 'represent' the original work, but still they are based on the original work.</p>
<p>Would it be copyright infringement (regardless of being fair use) to create and distribute such work without explicit permission of original works' copyright holders?</p>
<hr />
<p>(edit) I've found an example:</p>
<ul>
<li>original work : poem &quot;Eloisa to Abelard&quot; by Alexander Pope(1688-1744)</li>
<li>(potential) derivative work : film &quot;Eternal Sunshine of the Spotless Mind&quot; directed by Michel Gondry</li>
</ul>
<p>The film's title is a quotation from the poem, and the quoted part is cited within the film. Does it make the film a &quot;derivative work&quot; of the poem? Should the creation and distribution of the film have gotten permission from Alexander Pope (if he was still alive) or appropriate copyright holder of the poem?</p>
<hr />
<p>(edit 2) I looked for the word 'derivative' from dictionary:</p>
<blockquote>
<p>(typically of an artist or work of art) imitative of the work of another person, and usually disapproved of for that reason.</p>
<p>– from Oxford Language (through Google search)</p>
</blockquote>
<p>Now I see why the examples on the law were limited to 'representation' of the original work. I'm not a native English speaker, and thought 'derivative' means 'inspired or motivated by something'...</p>

<h2>Derivative Works under US law and the Berne Convention</h2>
<p>US Copyright law defines &quot;derivative work&quot; in <a href="https://www.copyright.gov/title17/92chap1.html#101" rel="nofollow noreferrer">17 USC 101</a> as:</p>
<blockquote>
<p>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”.</p>
</blockquote>
<p>Article 2 of the <a href="https://wipolex.wipo.int/en/text/283698" rel="nofollow noreferrer">Berne Copyright Convention</a> reads, in relevant part:</p>
<blockquote>
<p>(3) Translations, adaptations, arrangements of music and other alterations of a literary or artistic work shall be protected as original works without prejudice to the copyright in the original work.</p>
</blockquote>
<p>Under <a href="https://www.copyright.gov/title17/92chap1.html#106" rel="nofollow noreferrer">17 USC 106</a> one of the things that a copyright owner has the exclusive right to do or authorize is:</p>
<blockquote>
<p>(2) to prepare derivative works based upon the copyrighted work;</p>
</blockquote>
<p>Note that under the US definition, a derivative work is one <strong>based on</strong> an earlier work, not one that merely <strong>refers to</strong> a derivative work. Merely mentioning or citing a previous work is not enough to make the later work derivative. It must, in some substantial way, <strong>use</strong> and be developed out of the previous work.</p>
<p>The classic examples of a derivative work are: a translation into another language; an adaptation into another medium or form (such as making a novel into a play or film); and making a sequel. But derivative works can be derivative in various other ways.</p>
<h2>Examples from the Question</h2>
<p>Let us look at the examples mentioned in the question:</p>
<blockquote>
<ul>
<li>an academic paper that cites or refers to other papers</li>
</ul>
</blockquote>
<p>This is a mere reference and is not at all derivative. However a paper that contained little or no original content, but consisted almost entirely of such citations might be considered derivative.</p>
<blockquote>
<ul>
<li>a discussion thread on Internet (or each comment or reply on it) about a work</li>
</ul>
</blockquote>
<p>Discussion or criticism of a work, or a reply to it, is not normally considered derivative. Such comments are not derivative of the work under discussion, nor of the previous comments. Quotations of either are likely to be permitted fair use, and so not infringing, although that will depend on the exact details of each case.</p>
<blockquote>
<ul>
<li>a fanart or a fanfiction</li>
</ul>
</blockquote>
<p>This is likely to be a derivative work, depending on how much of the source work is used, and whether distinctive details are reproduced. Note that <strong>ideas</strong> cannot be protected by copyright. (See 17 USC 102(b) for this.) So the idea of a person who turns into an animal of a particular type, or has some special power or ability or characteristic is not protected by copyright. But the details expressed in the source work, such as the mannerisms or appearance of a character, or the specific nature of a setting, can be protected, and to draw on them may be infringement, unless fair use applies.</p>
<blockquote>
<ul>
<li>metadata</li>
</ul>
</blockquote>
<p>&quot;Metadata&quot; is a very general idea. Typically the kind of information included in metadata is not protected by copyright, but in some cases it may be.</p>
<blockquote>
<ul>
<li>a review or a criticism</li>
</ul>
</blockquote>
<p>A review, criticism of, or comment on an existing work is not normally considered a derivative work. Quotes used in a review or criticism are often protected by fair use under US law, but if the quotation is excessive, and particularly if it allows the review to serve as a replacement for the original and to harm the market for the original, it may be infringement.</p>
<blockquote>
<ul>
<li>a work inspired by other works</li>
</ul>
</blockquote>
<p>Again, this depends. If only the general idea is imitated, then the later work is not derivative If detailed, distinctive, and specific characters, settings or plot lines are imitated, then the later work may be considered derivative, and infringing if permission is not obtained.</p>
<h2>The <em>Nichols</em> Case</h2>
<p>In the case <a href="https://scholar.google.com/scholar_case?case=14991934121439658064&amp;q=Nichols+v.+Universal+Pictures+Corp.&amp;hl=en&amp;as_sdt=6,33" rel="nofollow noreferrer"><em>Nichols v. Universal Pictures Corporation</em>, 45 F. 2d 119 - Circuit Court of Appeals, 2nd Circuit (1930)</a> Judge Learned Hand, a famous judge, wrote a very influential and often cited opinion describing when two similar plays are, and when they are not, infringements of one another. It is worth reading to better understand this issue, even though it is over 90 years old.</p>
<h2>What makes a Work Derivative</h2>
<p>So in general a work is derivative when it uses significant, distinctive, and detailed elements of a previous work, or is a revised or altered version of the previous work.</p>
<h2>Copyright in a Derivative Work</h2>
<p>If a derivative work is made with proper permission, or the source work is out of copyright, the author of the derivative work has copyright in all the original parts of the derivative work. However if the derivative work is infringing, and was created without permission, the author has no valid copyright in it at all.</p>
<h2>Fair Use and True Parody</h2>
<p>If a work is held to be a <em><strong>fair use</strong></em> of the original, it is not infringing even if it is a derivative work, this is an <em><strong>exception to copyright</strong></em> in US law. It may still be important to note that the work is derivative, because the author has copyright only in the original aspects.</p>
<p>If a work is a <em><strong>parody</strong></em>, it is likely to be held to be a fair use. Note that in copyright law a <strong>true</strong> parody is a work that comments on the source work by imitating or mocking it. A work that imitates a source work merely to be funny, or to comment on general social conditions, or to make some other point, but <strong>not</strong> to comment on the original, is not a parody in US copyright law. Courts often refer to such a work as a &quot;satire&quot;, even though this is not the standard literary definition of &quot;satire&quot;. A Satire will usually not be a fair use of the source, or if it is, it will be for other reasons.</p>
<p><strong>Addition</strong> (in response to an addition to the question)</p>
<blockquote>
<ul>
<li>original work : poem &quot;Eloisa to Abelard&quot; by Alexander Pope(1688-1744)</li>
<li>(potential) derivative work : film &quot;Eternal Sunshine of the Spotless Mind&quot; directed by Michel Gondry</li>
</ul>
<p>The film's title is a quotation from the poem, and the quoted part is cited within the film. Does it make the film a &quot;derivative work&quot; of the poem?</p>
</blockquote>
<p>No. First of all, any copyright on the poem has long expired, it is in the public domain.</p>
<p>Secondly, merely referring to a previous work in the title and citing it in the body does not make the later work derivative, it is merely a <em><strong>literary reference</strong></em>. A significant part of the earlier work would need to be used to make the film derivative. Unless much more was used than is mentioned above, this would not qualify even if the poem were still in copyright.</p>
<h3>Meaning of &quot;Derivative&quot;</h3>
<p>Like many other words of the English language, the word &quot;derivative&quot; has several different senses. The sense leading to the definitions:</p>
<blockquote>
<ul>
<li>imitative of the work of another person</li>
<li>inspired or motivated by something</li>
</ul>
</blockquote>
<p>is mostly used in the context of criticism and review of works of art or literature. In copyright law,  &quot;derivative&quot; is a technical term, defined by the definition section of the law, and by previous court cases.  It is not unrelated to the meaning from literary or art criticism, but it is specific and by no means the same.  The word &quot;derivative&quot; also has other specialized meanings, for example in chemistry, and in mathematics.</p>

<p>Let's go through them one by one</p>
<blockquote>
<p>an academic paper that cites or refers to other papers</p>
</blockquote>
<p>Exemption from Copyright applies. You have no copyright on the fact that someone said something, only on the manner how. However, Scientific and academic works are a fundamental fair use, especially with a proper citation. They bring citations usually as &quot;X said this: ...&quot;.</p>
<blockquote>
<p>a discussion thread on Internet (or each comment or reply on it) about a work</p>
</blockquote>
<p>The text written in the thread is copyrighted by the makers of each text piece, but message boards are ultimately discussions, where the words are preserved and form a joint work. The Discussion itself is a fundamental fair use, but usage by others can be Copyright infringement.</p>
<blockquote>
<p>a fanart or a fanfiction</p>
</blockquote>
<p>These depend. A fanfiction to a book or other story <strong>is</strong> a derivative, as is a fanart to an other visual expression. As a result, these <strong>can</strong> be copyright infringement.</p>
<blockquote>
<p>metadata</p>
</blockquote>
<p>Metadata are of two kinds: There's copyright management information. And there is just facts about the file.</p>
<p>The first kind Are generally things you may not remove as you would remove copyright management information, which is illegal.</p>
<p>However the other kind of metadata, facts about the file or contents, are automatically generated, are facts and have no copyright. Facts like &quot;made on the X/Y/Z by ABC&quot; are not subject to copyright at all: they are not creative and thus warrant no copyright protection.</p>
<blockquote>
<p>a review or a criticism</p>
</blockquote>
<p>Criticism and Commentary are explicitly exempt from infringing copyright.</p>
<blockquote>
<p>a work inspired by other works</p>
</blockquote>
<p>This depends heavily: The more visible the inspiration and the less own expression it has, the more it might become an infringement of copyright.</p>
<p>If you just write Rocky X... <a href="https://law.stackexchange.com/a/53604/10334">you infringe.</a> Just like the Stallone case.</p>
<p>If you write a story about a Boxer that is clearly inspired in its storytelling by the training montages from Rocky, but set it in 1930s Germany, have the main character inspired by <a href="https://en.wikipedia.org/wiki/Max_Schmeling" rel="nofollow noreferrer">Max Schmeling</a> and develop a somewhat <strong>different</strong> story, you might become not infringing.</p>

copyright derivative-work