Such a "field" doesn't really exist. I think the only relevant field
"Arc Riley" <firstname.lastname@example.org
> IANAL and am not presenting a legal opinion. What I am speaking
> about here is based on numerous conversations I've had with lawyers
> in the "IP" (sic) field.
for this discussion is copyright law.
and that would be why I put quotes around "IP" and followed it with (sic).
I agree entirely that all bitstreams are software, and it makes little
sense from a copyright perspective to try labelling them with
different copyright status based on how they happen to be interpreted
at a given point in time .
Especially when they inter-link.
What you're describing is more like writing a "game program" using the
"programming language" of the game engine. None of the copyright work
actually makes its way, even in derived form, into your work.
That is like saying that writing a set of replacement functions with the same names, arguments, and return types does not constitute a derived work when it's purpose is to replace specific source files in a GPL licensed work.
Under copyright law, at least in the US, you can write software that provides the same function as a copyrighted piece of software and it's not a derived work. You can even provide the same external API, reference Wine given that Wine is a complete implementation. You cannot however release patches and claim they are not a derived work because they don't contain any of the original work in them.
This comes back to what I was saying before, it apparently doesn't matter how the pieces fit together, it matters what the whole is. It's a matter of common sense human judgement. Obviously you're creating a derived work by putting together a set of "content" software, regardless of whether that "content" includes instruction code or media, which is crafted in such a way to replace or supplement an existing piece of work.
Consider this from the other side of the fence. You put together a supplemental "content" set that expands Blizzard's World of Warcraft (I don't know if this is technically feasable but lets assume it is), they take you to court for violating their copyright in creating a derived work, and the judge looks at the situation in it's whole. Your "content" is meaningless pieces without the game code behind it, it is not intended to be presented on it's own and needs Blizzard's copyrighted work to run, extending or expanding it's functionality. This is the context that it was explained to me, though I may not be explaining it correctly.