Hello, community. Like many of you, I am a nerd. I am also a lawyer. With all the OGL controversy, I have been seeing a lot of claims on the internet, here and elsewhere, about what the OGL is and how it interacts with third party content and copyright law. Many of these claims are, in my opinion, spurious or inaccurate. For anyone interested in the law behind this issue, I would like to clarify a few things. And remember, this is not legal advice. Legal advice is when you tell me your problems, and I tell you what to do. Here, I am just talking about the law generally.
First, the OGL is likely not irrevocable. I've seen many people saying that, for some reason, Wizards of the Coast cannot revoke earlier versions of their license; that the license, once put out, can never be taken away, and that people and companies can keep making content for 5e forever.
This is false. There is nothing about the OGL that makes it so Wizards can never revoke it. Some language, at first glance, may appear to contradict this claim. But it doesn't. For instance, the license states that WotC grants the licensee "a perpetual, worldwide, royalty-free, nonexclusive license" to use the SRD. But "perpetual," in licensing law, does not mean "irrevocable." In fact, unless the word "irrevocable" appears in the license, the license can be revoked at any time, for any reason or for no reason. Even in cases where a party has had substantial reliance on the license, the revocation is usually upheld. Here is an excellent article on the subject: The Terms “Revocable” and “Irrevocable” in License Agreements: Tips and Pitfalls | Casetext
The OGL also states that earlier versions of the license may be used. But if the next license revokes the current OGL, then that sentence is also revoked. Even though the OGL acts like a contract, WotC would not be in breach of the contract merely by revoking the OGL. Contracts do not last forever, especially open-ended ones like this.
The good news is that, because of the reliance principle, third party creators who have already created a work under the OGL likely could continue to sell that work even if the OGL were revoked. They just could not create any new works. Kobold Press's "Tome of Beasts" would not have to be removed from the market, for instance. But they might have trouble doing a new one down the line.
Second, some people claim that the OGL is actually not necessary, that all the material in the SRD is "game mechanics," and therefore cannot be copyrighted. It is true that "game mechanics" cannot be copyrighted, but what constitutes "game mechanics" is a nebulous subject, interpreted differently by different courts, and not a matter of settled law. In game mechanics cases, the courts were usually dealing with things like rolling a dice and moving a set number of spaces, like in "Sorry." I have not been able to find any games mechanics cases on RPGs.
It is likely that the SRD is a combination of "game mechanics" and original copyrightable content. The six ability scores and twelve classes are specific and complex enough that many courts probably would be uncomfortable calling them mere "game mechanics" that cannot be copyrighted. Other courts might interpret it differently.
It is all about a larger copyright concept, wherein "ideas" cannot be copyrighted, but "expressions" can. This is super complex, famously confounding even to legal scholars, and a little beside the point, so I won't go into it here. If you are interested in reading more on the subject, I recommend an article called "Games and other uncopyrightable systems," 18 Geo. Mason L. Rev. 439.
"But even if the SRD is protected by copyright, I won't violate WotC's copyrights as long as I don't print SRD word-for-word, right?"
Wrong. That brings me to my third point.
Third, not only is the SRD protected, but any derivative works of the SRD are protected. A derivative work is a work based on, or derived from, a work that has already been copyrighted. Copyright protections protect not only the original work, but also any derivative works. I cannot write an eighth Harry Potter novel and then go out and sell it. Harry Potter 8 would not be a copy--a "reproduction" in copyright parlance--because Rowling has not written Harry Potter 8. But I still could not write it myself and sell it. Why? Because Harry Potter 8 would be a derivative work.
There's a lot of nuance on what is or is not derivative. For instance, someone wrote a Harry Potter Encyclopedia, and J.K. Rowling sued, and the Encyclopedia owner won on the copyright claim, because the court held that the Encyclopedia was different enough--the Harry Potter books were novels, not encyclopedias--that it was not a derivative work. The encyclopedia was not competing with her novels, but merely assisting the reader. A 5e sourcebook, however, might compete with official 5e sourcebooks in the eyes of a reviewing court.
Bottom line. Without the OGL and SRD, any person wanting to make content for 5e without WotC's permission would have to parse through the document and try to determine what is really "game mechanics" and what are expressions of WotC's original creation. And then, when writing their document, they would have to determine if their work is derivative of WotC's. Are subclasses derivative of the original class? Are new dragon statblocks derivative of existing dragon statblocks? I don't know the answer to this, and neither does any lawyer on Earth, because it has almost never been tested in litigation. Even small differences in the doc could make a huge difference in court.
I post this as a PSA, because, based on the advice I have been seeing from nonlawyers, people are being steered in the wrong direction. I know this will be bad news to most people, so don't shoot the messenger.
Moralité : j'ai bien fait de ne pas me lancer sur une version 5e de la Cité sans Nom (et de ne pas lier la CSN a une quelconque version des règles de Donj' )
ça veut dire que ça implique aussi les gens qui produisent des rétroclones 
