<<As I read that, it means that anything in an OGL work that
constitutes a game mechanic can be reused under the license,
regardless of whether the publisher has declared that the mechanic is
open or closed.
If I recall correctly, we had a discussion here about what would
happen if an RPG publisher included an original card game as part of
an OGL work but did not declare it as open. The rules of the game
would be open content, though the particular expression of those
rules and the card images and name could be product identity.
>>
In addition to verbatim expression (which you have noted may be closed), the PI declarations allow for "concepts" to be closed.
The point of debate is whether the "language" and "concept" declarations of product identity could be used to protect an original rule. Green Ronin has clearly read the OGL to this effect in trying to close up some of their rules that they felt were original to them.
Since concepts and verbatim language can be closed, presumably a rule's concept and verbatim form of expression could be declared closed under these standards provided that you were the copyright holder of the verbatim expression and provided that said rule was not particularly derivative of a pre-existing rule that was declared as OGC in a work in your Section 15.
Others on the list disagree, but I think this is a perfectly reasonable reading of the language and concepts PI declarations. To the extent that a rule can be expressed without being derivative of the PI'd concepts and verbatim languages others could use it under the OGL, but I can't even begin to imagine a way to express a rule without relying either on its concepts or its verbatim language at some level, so this seems to be a viable way to close up rules content.
Were "concepts" not protectable under the OGL then I would not necessarily hold this viewpoint.
Some variant of this premise must have been drawn upon by Green Ronin and some other publishers who have closed down rules they have invented, but which they felt were not particularly derivative of the SRD in any way.
The strange thing is, however, that if you don't Section 15 a particular product that has closed rules, then you probably can reuse some of those rules provided you don't copy their verbatim expression. Because if it isn't in your Section 15, then the author of the closed rules hasn't entered into a licensing agreement with you, and you are then bound only by copyright and patent law. The only problem with that approach is that you have then left the "safe harbor" provided by the OGL, one of the OGL's primary advantages.
Lee
