Hello!

I am a hobbyist game developer currently involved in the development of a free and open source game engine. As the engine and it's first game are nearing completion, I'm planning to reuse this engine to remake a classic 1980's computer game. Of course, I will not be copying any assets or code from the original game.

The first half of this project will require the development of some additional C++ engine plugin modules to represent the elements of the game - simple objects such as moving platforms, enemies, terrain, etc. as well as modules to generate simple assets such as textures, sprites, etc. All assets of the game are sufficiently simple that I don't need to load them from external files.

I believe that these C++ modules can be designed and constructed in a generic reusable way that does not imply any relationship to the remake that I will be using them in. For this reason, I strongly believe that the C++ code on its own cannot lead to any risks of infringement.

The second half of this project will require that I use my engine tools to load the C++ modules and instantiate objects from them into a configuration that mimics the mechanics, layout, rules, assets, etc. of the game that I want to remake. The resulting deliverable of this work will be an XML file that can be read by my game engine in order to generate and run the final game.

This is where things become murky. It's hard for me to see how either half - the C++ code and the XML project file - can be infringing on its own. As stated already, I'm certain that the C++ modules will be too generic to be infringing.

The XML file may be a little more questionable. Technically, it will represent a description of the game, but will be written in a custom format that is only understood by my engine and the required plugin modules. The XML file is therefore meaningless outside the context of my engine and the modules that interpret its contents into a playable game.

As such, it seems to me that only a combination package of both the engine containing the necessary C++ modules and the game XML file together can possibly be deemed to be infringing.

So here are my questions:

At what point exactly does infringement occur?

Assuming that neither half can infringe on its own, can I distribute the engine and the game XML as two separate non-infringing packages?

Assuming this isn't possible, can I distribute the XML without explicitly stating it's intention to be used in conjunction with the game engine and let users figure it out for themselves?

In the case scenario above, can I give the XML file a custom file extension that also happens by co-incidence to be associated with the engine executable, making it easy for players to run simply by double clicking the game XML file? Would this change the situation?

In case this would still considered an infringement, then where is the line drawn?

If I create an XML file that mimics the game mechanics, but using different sprites, textures, sounds and map layout, is the project still an infringement? How about just using a different map layout?

It may be worth mentioning that the engine is distributed with the same editing tools that I use to build the game XML file and is designed to facilitate and encourage user generated content.

As a consequence, this means that players can build their own map layouts based on existing project mechanics or even create games themselves from scratch.

Assuming I can safely include a project with matching mechanics of the game but not with the same map layout, then it will be fairly trivial for any user to rebuild the original map layout of the game in question using my project as a basis. Would the inclusion of this capability make the infringement problem any more difficult to deal with?

I haven't found much information pertaining to remakes composed of multiple dependent parts, so any advice on this would be much appreciated. :)

The second half of this project will require that I use my engine tools to load the C++ modules and instantiate objects from them into a configuration that mimics the mechanics, layout, rules, assets, etc. of the game that I want to remake. The resulting deliverable of this work will be an XML file that can be read by my game engine in order to generate and run the final game.

I'd argue that this is clearly infringing.

If I sit at home and record my own version of a pop song, distributing that (without obtaining permission or a valid licence) is copyright infringement. It doesn't matter that I didn't use any of the original recording, or any of the instruments or people that went into making it. What I have done is reproduced the creative work. My final MP3 does not resemble the original recording in terms of bits and bytes, and even when combined with an MP3 playing program does still not exactly resemble the the original work, but the output can be heard to be derived from the original - and that is enough to make it a clear derivative of the original work.

So it is with your situation. A C++ program and the XML files are only the media here. The work itself is encoded on them. If it were possible to avoid liability by distributing parts separately and forcing the recipient to wilfully re-assemble them, we'd have seen that defence encoded algorithmically into file-sharing apps by now.

If you choose to use different sprites, textures, sounds and map layout, then the project is likely to be non-infringing. Apart from a few ridiculous exceptions (usually granted by the US Patent Office), game rules and general concepts are not protectable intellectual property.

The pop song recording and VLC/movie distribution examples are interesting. However, in both of these examples, the infringing nature of the recording and the movie can be immediately revealed by existing software.

In my case, my engine is currently not released, so it may be possible to approach in a different way. How about this:

Let's say I only distribute the XML file without revealing it's meaning or purpose other than stating that it is later to become a required part of a free game. Without an engine to interpret the XML, it is not possible to reveal what the XML represents and therefore the XML cannot be shown to be infringing. As such, the meaningless XML file must surely be legal to distribute and possess at this stage.

Now, let's assume that some people download the XML file in anticipation of later using it to play the promised free game.

Later, once the XML file is sufficiently out in the wild, I then release the engine to read it. Suddenly the XML file becomes illegal copyright infringement because the engine reveals that the XML represents a remake of an existing game.

What effect does this have on those who already obtained a copy of the XML when it was a non-infringing file? Do those people suddenly and unknowingly become guilty of possession of copyright infringing content?

Let's say I cease distribution of the XML file immediately before release of the engine and rely on the community to redistribute the game XML via torrents, etc. Since the XML content was not infringing at the time that I distributed it, can I still be considered guilty of infringement?

I do realise this would be kind of ridiculous in practice and I don't really anticipate legal problems in my endeavour to recreate a long forgotten obscure 1980's computer game. I'm really more just curious.

To be honest - I think you are overthinking the entire situation. A deliberate workaround such as you just suggested is more likely to establish "intent" than simply releasing.

However my question is this: Have you checked the IP holder's status on such use as you would seek or checked their website, or sought similar infringement examples being enforced with regard to your particulars?

The main reason I brought up the music analogy is because it shows that copyright protection applies to more than just the final physical representation of the work. A musical recording having 2 separate types of rights is not really a special case because it's actually 2 separate works: the composition, and the recording of that composition. The same can apply to any creative work that ends up creatively arranged or portrayed. (eg. Writing a book based on the dialogue from a film - the dialogue as it's written is protected even if you're not copying the audio or the video of it being delivered.)

The reason why games would have to be extremely similar to count as infringing whereas merely humming someone else's song is covered, is because game mechanics, rules, etc., all fall outside of the scope of copyright. They don't count as creative works for copyright purposes. But when you copy some of the way the game is expressed, by replicating the assets or attempting to match the look-and-feel closely - then you're crossing over into the realm of copyright.