Go to the Open Gaming Foundation (http://www.opengamingfoundation.org) and sign up to the ogf-l list, and read the archives. It was a *long* discussion, over several months, if not years. Pay special attention to Ryan Dancey, Alec [forgot-his-last-name], and Clark Peterson (and i think there's one more of actual legal training, but i forget who it is).Fester said:Interesting interpretation. I'd be interested to see any discussion threads on this, if you could point me in the right direction.
My reading of those sections is that you can use OGC, but are not required to declare your own product as OGC. OGC material used must be declared in the license, but remains OGC. You are also required to include a copy of the license with any products that uses OGC.
Of course, the word derivative is ambiguous, so I may have misinterpreted what you meant by it. My interpretation of what you're saying is that pretty much anything that uses the SRD is a derivative of it and hence is required to be OGC - and that doesn't seem right. Excsue me if I'm just being dumb and that isn't what you meant.
The license seems to revolve around derivative elements, not derivative works. So, if you use the OGC troll stats to create a cyber-troll, you have to make the cyber-troll OGC. Now, some have argued that anything compatible with D20 System mechanics is using D20 System mechanics, and anything using them must therefore be derivative of them, and that therefore any D20 System product must make all rules OGC, because they're all derivative. With the possible exception of those that have a clear prior history elsewhere (such as the starship construction rules in T20)--though some have even argued that simply making them compatible makes them "derivative" of D20 System. Personally, i don't buy that--i think you could make, say, a completely new magic system and make it not-OGC, but it's not clear.
So, the license is viral but not infectious--once something is OGC, it not only remains OGC, but anything derived from it must also be OGC; but an entire work isn't required to be OGC just because it has some OGC in it.