One thing about copyright law that often confuses authors, and many other people, is what it means to “copy” someone else’s work for infringement purposes. A copyright holder has a number of exclusive rights in their work under our law. The main rights that concern authors typically relate to “reproduction” (ie copying) and “distribution” (ie sale, license, sharing etc.).
But what does “copying” mean for these purposes?
Word-for-word literal copying is an infringement of a copyright, but simply using the same or a similar overall concept or idea is not generally a copyright infringement. What about everything in between? What about copying the plotline very closely but changing the setting and character names?
That’s where the substantial similarity concept comes in.
It wouldn’t make much sense if only exact copies amounted to a copyright infringement because then someone could change a handful of words and avoid infringing your copyright. On the other hand, we don’t want copyright law to prevent people from creating new works in similar areas with similar ideas behind them. Think about vampire books: many readers can’t get enough of them (while many would be happy to never see another vampire book as long as they live.).
Many vampire books have similar basic characters and plots, especially these days in the paranormal adventure/romance area, but there isn’t a heck of a lot of copyright infringement going on.
Some of this may be because authors and publishers don’t want to sue each other, or because what is being copied is so minor (de minimis, in legal-speak) or because what is being copied are elements of the work that are in the public domain: you can copy Bram Stoker’s work all you like; its copyright has long expired.
But in many cases the works in question simply may not be substantially similar for copyright purposes. Courts approach the issue of “substantial similarity” in different ways and many law professors have spilled a lot of ink trying to explain the concept in simple legal or layperson’s terms. One of the problems with the current system—and with trying to advise authors who are worried that their work has been infringed or that their work may infringe someone else’s—is that there’s a lot of space on the continuum between direct, literal copying and writing to a generally similar idea.
If you find yourself in this middle ground, you may want to seek legal advice from a copyright expert. However, by way of fair warning, you may get as many answers as there are lawyers that you consult. You’d think it would be easy to say whether something is “substantially similar” to something else, but it’s often not as easy as we would like it to be.
The good news is that the bottom line in a copyright case is often not actually about substantial similarity. There will be questions as to whether you actually copied: for example, if you never saw the original work and you coincidentally came up with a similar idea (happens more often than you might think), your work will not be a copy for copyright purposes.
There are also a number of copyright defenses like fair use that excuse some kinds of copying. A lot of parody is fair use. Some fanfiction, especially noncommercial fanfiction, may also be fair use. Again, it’s case specific, but the fair use defense is an escape valve from copyright infringement in some situations.
Additionally, in the writing context in particular, there are copyright doctrines like the scènes à faire doctrine which acknowledge that certain genres rely on particular themes, incidents, plotlines, character types, etc. For example the: boy meets girl, boy loses girl, boy gets girl trope from the classical romance genre. Many vampire tropes probably qualify as scènes à faire too: like sunlight being fatal, sleeping in coffins during the day, wearing black capes, and biting their victims with animal-like incisors.
It’s important to remember that there’s more to copying, and to copyright infringement, than easy cases of cutting and pasting. If your situation gets too far down a copyright rabbit hole, it can be worth seeking independent advice just in case.
And of course my usual disclaimer applies: nothing in this column is intended as formal legal advice, but hopefully it is helpful by way of background information.