Copyright, Binary Code, and Share-Alike Clauses?

Question

I do extensive personal work in the modding/romhacking space of games. This space is about taking existing commercial games and adding custom content or features to them, generally through unofficial means. These changes are then released as patches, so as not to violate the copyright or DRM of the original game. I write specs based on my research, utilities, and some hacks myself. The last couple of years, when I release utilities (which these days I write in Python - a non-compiled language) or specs I use the Creative Commons Attribution-ShareAlike 4.0 International license, as attribution and share-alike are my two copyright concerns.

However, I'm now looking to publish some closed-source hacks as patches. They are utility hacks that are useful to other hackers making their hacks, e.g. one of mine optimizes one part of the game's code, increasing performance and reducing slowdown by several percent. I'm wondering how copyright even works in this case. As intended, the license allows them to creative derivative hacks, so I could certainly see attribution being a reasonable and enforceable requirement. But does the concept of share-alike even apply in a context where I'm releasing binary code and anyone who derived from my hack would necessarily have to release their binary code as well, as there's no point in making a hack you never publish? If not then I guess the question is moot and I should just drop the share-alike clause entirely. But if it does apply, how does it apply to this circumstance?

I do like the idea of requiring improvements to my code (e.g. Person X makes Improved Improved Performance Hack that adds further optimizations on top of mine) to be made available as well, but I am not aware of any way in which the law differentiates between utility hacks like that and complete hacks, e.g. where my optimizations are used in a much bigger hack that has custom levels, etc. In such a case I certainly don't want to force limitations on their entire hack by forcing a specific license just because they incorporate my improvements.

Answer 1

First of all, when you say

These changes are then released as patches, so as not to violate the copyright or DRM of the original game.

... I assume you have consulted an attorney with expertise in the relevant topic and jurisdiction, because otherwise, you might be in for a bad surprise.

For the sake of the argument, let’s assume that you indeed are free to distribute your work under whatever license you desire. I suspect your surprise comes from not understanding what "sharealike" means in the CC-BY-SA license (full text here).

"Sharealike" is purely about the license, not the format

The format of your work is irrelevant (Python code, binary executables, images, sounds, whatever as long as it can be copyrighted). The CC license cover it all the same.

The share-alike clause only imposes that someone who uses your work to produce something else and distribute it must license that something else under a compatible license. It does not impose that it should be the same or similar format. In fact, it says in section 2(a)4:

Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. (...)

In particular, if you publish source code, someone else can come around and produce a binary patch based on that, without publishing the associated code, and they’re in the clear as long as they respect the license clauses. Alternatively, if you publish a binary executable, they can try and decompile it and publish source code under the same conditions.

If you want to prevent that kind of use, you need a different license. Typically, the need to provide source code alongside binaries is contained in so-called "copyleft" clauses, such as the one included in the GNU GPL (but also other licenses).

Wait, I read something about "effective technological measures"

The CC-SA license says at section 3(b)3:

You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, Adapted Material that restrict exercise of the rights granted under the Adapter's License You apply.

One might superficially imagine that publishing a closed patch is such an "effective technological measure". However, if you scroll up, such measures are

those measures that, in the absence of proper authority, may not be circumvented under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, and/or similar international agreements.

Roughly speaking, that means DRMs. Not purely technical barriers such as a difficulty to convert from one format to another.