Sir Edgar said:
By the way, I'm not a publisher, just curious about the system.
Anyhow, I don't know why you even need the SRD if game mechanics cannot be copyrighted.
Well, the SRD also contains content that are not defined as game mechanics, like the description of a spell.
Is the Lord of the Rings RPG using the SRD?
Nope, because it is an entirely different rules system based on similar concepts. And they're not literally using a d20 in their game, but a 2d6. But in this case, their marketing scheme is based on the
LOTR brand label to market their
Coda System product.
What about the Everquest RPG? It seems the companies that printed these games used a lot of the game mechanics in 3e D&D and they may have indeed followed the guidelines of the SRD, but did they (legally) have to?
If they're using the content from the SRD verbatim, then yes.
But in addition to using OGC from the SRD or other OGL-based sources, authors can contribute their own OGC and made it available to the public through the license.
Also, about paragraph 15, can you tell me more about it? I don't quite understand the implications of it fully.
The copyright notice simply list the sources of the Open Game Content you use for your product. It also provides a "family tree" of an original OGC that have been modified from one product to another. It also help any publisher who is willing to research what OGC he wants to use.
Also, I don't understand how a certain d20 company put "Vortigern" as its Product Identity. Vortigern is a historical name and doesn't belong to anyone. I guess again it depends on context, but it seems even the name Gandalf which is also a pseudo-historical name can be protected.
Well, if the author can make such distinction, then they can consider it copyright or trademarked. For example while a barbarian named Conan may not be trademarked, the titular character that have graced the pages of Robert E Howard's books can be.
In the above case, the author may have wanted Vortigern to be associated to a particular (iconic) character in his game and/or setting.