Thread: Legality of making a game clone

Recently I've been thinking about "remaking" a PC game from 1999 (Caesar III) for Android. I have no relationship with the original developers, and the studio does not exist any more.

I do not have access to the source code, and will not attempt to decompile the game. I'll write all the code from scratch, basing the mechanism on just what I observe by playing the game.

AFAIK, gameplay is not protectable (by copyright, and there certainly were no software patents back then), so that part should be fine.

However, would there be anything wrong with supplying a tool to convert game graphics, etc, from the original game, to be used in my game? If I don't distribute the files with my game? (requiring the user to own a copy of the original game)

Does anyone have experience doing something like this?

Thanks!

The EULA only talks about commercializing.

You are entitled to use the Program for your own use, but you are not entitled to:
...
(ii) exploit the Program or any of its parts for any commercial purpose including, but not limited to, use at a cyber café, computer gaming center or any other location-based site. Sierra may offer a separate Site License Agreement to permit you to make the Program available for commercial use; contact Sierra for details;

Funny thing. I've had the same idea before. It went along the lines of this: I'll sell this CLI software package as propriety, but include an open source GUI wrapper around it, to get around the Qt licensing. The end result is that my technology would remain money-making, and not have to pay for a costly commercial Qt license. The end user would never notice the difference, but I would save $. It's hard to say, both because different licenses matter, and I'm far from an expert on this stuff, but it would seem logical to say that the answer to whether my idea is legal/compliant, yours would be to.

Qt's license isn't even of any concern now, because it's under the LGPL. you can use it in closed source projects as long as you dynamically link.

I intend to GPL the game, so hopefully even if it's in grey area, no one will come knocking on my door.

I believe in the context of software engineering, "decompile" only applies to code, since the inner workings of the game could contain trade secrets. Art assets, on the other hand, are shown in their entirety in the game, and don't hold any secrets. I could conceivably just go into the game and take screenshots, then crop out the parts I want.

I got the idea of supplying a tool that converts the graphics from how game console emulators do it. They cannot work without the original console ROM, but they cannot supply the ROM since that's the company's IP. So they just supply tools to extract the ROM from a console that the user must own. This must be legal because there are several very popular emulators (including PCSX2 for PS2) doing it this way, and they are obviously taking profit away from Sony. If Sony can sue them, they probably would have already, judging by how trigger happy they have been with suing everyone.

I researched a bit into how game companies deal with this, and surprisingly, it looks like they actually SUPPORT non-commercial derivative works based on their game content, which makes sense, since it's free publicity, and has very little potential for stealing profit. Microsoft and Blizzard even explicitly license it.

Game Content Usage Rules - Xbox.com
Blizzard Entertainment: Blizzard Video Policy

In those cases, it's actually possible to redistribute game assets.

However, many other companies prefer to just not enforce copyright, because of "legal complexities" in licensing.

I think the method you're trying to extract the art, won't give good results at all.
Why not make some vector graphics yourself...based on the original contents ?

It's a 1999 game. Art is very easy to extract. They are basically just sprites concatenated into data files.

Here are what the sprites look like - http://caesar3.heavengames.com/cpix/...umPalaces1.jpg

Beautiful game.

if you extract the artwork, and use it in any way without prior permission from the owners, that's a copyright violation.
If you use the same ideas and concepts, especially with the same names, you may be looking at a trademark violation as well.

Some companies and IP owners are far more likely and aggressive in going after such things than are others, and when they are coming after you they won't care whether it's free or commercial, open source or not (in fact it's quite possible they'll be more aggressive if it's open source because the commercial damage to them from you releasing their artwork and other content to the world under a license which makes it look like the work is in the public domain is potentially far greater).

I am aware that if I distribute the artwork with my game, it will be copyright violation (which may or may not be enforced).

But now my question is, is it still copyright violation, if, instead of distributing the artwork with the game, I include a tool to extract artwork from the original game, and convert it to a format my game can use?

Technically then, no one is violating copyright because I (developer) never distributed copyrighted content. The user also doesn't violate copyright because he only made a copy of the original artwork (using my program), for his personal use (no distribution). This is comparable to the emulator-and-ROM case I mentioned earlier.

I will try to avoid the trademarked name (though I doubt a name as generic as "Caesar" is enforceable), but I'm pretty sure ideas and concepts are not protectable (at least without software patents, which didn't exist back then).

IANAL! and all that fluff.

But now my question is, is it still copyright violation, if, instead of distributing the artwork with the game, I include a tool to extract artwork from the original game, and convert it to a format my game can use?

At the very least, that isn't a copyright violation on your part. As long as you are telling people "This is a mechanical clone of the GAME for PLATFORM, but you must provide the DATA files from a copy of GAME that you own." you aren't even enticing people to violate the copyright.

There is good precedence for this in the United States.

However, I suggest you code your tools into your game. What I'm saying is, the tools and the game shouldn't be a separate entity. Depending on exactly what you are going to do, this becomes an important distinction.

That said, in the United States you have the issue of DRM. If the game uses a DRM related method to protect the data files you need to use, even if it is a crappy one, you may be understood to be distributing a "DRM circumvention" device as setup in the "DMCA". Unfortunately, in the United States, some violations have cost developers everything even though the originator of the copyrighted material had distributed versions with and without DRM.

This issue has had some interesting results in the United States; if anyone is interested in how the "DMCA" hurts us as programmers I strongly suggest you read more relating to this issue.

Soma

Originally Posted by MK27

I think Yarin's parallel is way off base in so far as what s/he is suggesting involves a presumably original concept and the use of generic technology, whereas what you are suggesting involves the re-use of a concept in a newer, but still generic, context.

I suppose that's true. The parallel I was trying to draw, is that both are simply packaged differently in an attempt to get around imposing licenses. (though it is nice to know that dynamic linking is sufficient now)

Originally Posted by phantomotap

If the game uses a DRM related method to protect the data files you need to use, even if it is a crappy one, you may be understood to be distributing a "DRM circumvention" device as setup in the "DMCA".

Even if it were, is that really grounds for a lawsuit? Esp. if the game didn't require the graphics extraction, but did required the user's express desire to do so.
Think of Nmap and John the Ripper, AFAIK, they are not illegal, but it would be to use them in the wrong way. Maybe another bad parallel, dunno.

Thanks! That's exactly what I'm planning to do. However, it's strange that they also supply the data files as a separate download...