Alzrius
The EN World kitten
S'mon said:No. Game-rules compatibility as such does not equal derivative work or any other kind of copyright infringement.
From what I understand, this isn't true (though I could be wrong); the major example of I can think of here is that TSR sued Mayfair Games into oblivion over their Role Aids line of D&D-compatible products.
& NOBODY _needs_ to use the d20 license unless they are putting the d20 trademark on their release. However there is no need to worry about any of this anyway as the IH uses the OGL!
I did say "at least the OGL." That said, while it is good that nothing in the IH is violating any part of the basic OGL (and isn't using the d20 License, so it avoids that fiasco), I would still really like to see the aforementioned portions of it made OGC.