Public domain and free of charge are not intrinsically tied. It's like free speech vs free beer, as the open source people say.
Thus, scenariowrights own the complete rights to their works and can dictate how they are used. As for using snippets of the original game, one could make the argument that scenarios are thus derivative works and Bungie owns the right to them because the scenariowrights had no rights to even make it, except that Bungie has explicitly said that what YOU MAKE for a scenario is owned by you; the rest of the content, and specifically the file formats (BFD? the demos distribute the file formats free of charge), is owned by Bungie, which is why you can't distribute a modified shapes file (but can you patch a demo file? Would amount to the same thing, ship the Infinity demo with your game as a part of the "install package"). Their lack of enforcement regarding certain content (logos, modified textures and weapons, etc) is I believe legally considered implicit permission to use for such purposes.
'Ethically' though, I think you're right, scenariowrights should let people spread their work far and wide. But legally they have the right to control what is done with their works.
On a tangential topic: does anybody know if there is a legally approved process for distributing a scenario for Aleph One, with *lots* of modified content (all new textures, weapons, landscapes, new and modified monsters, all new maps of course, entirely changed interface and new music) but some original Marathon content too, in a format that anybody, Mac or PC, own Marathon or not, can download and play the thing with a simple installer? The best I can think right now is to test that patches work on the demo, make the installer acknowledge the demo too, and in the download instructions say that you must have SOME version of Marathon Infinity to install this, even if just the demo, and then link to the demo download. And then have another version that works for SLD, and link to the Aleph One SDL page for the appropriate app.
Does anyone have a better solution?
