Is it legal to program a published game for educational purposes (and put the source code on GitHub)? I own a card game that I enjoy playing (not a playing card game using a standard 52-card deck). I enjoy it enough that I thought it'd be fun to write a program (complete with AI!) that plays that game. Is this legal? Furthermore, may I publish the source code to a public website such as GitHub without incurring any legal issues? Assuming it's illegal for me to do this, at what point does doing this become legal? I likely cannot simply change all the names of the various cards to something else, right? If I start changing the rules of the game, does that make it legal for me to share my source code, for instance? It'd be a game that's heavily inspired by the original, but isn't (different rules, different cards, different amounts even).
If any elements of the game are protected by copyright, then you cannot reproduce those elements (17 U.S.C. §106) unless your reproduction falls under a fair use exception (17 U.S.C. §107). Elements that may be protected by copyright include: artwork specific language on each card the aggregate effects of the cards (i.e. copying a single card's effects might not infringe copyright, but if you copy the effect of a bunch of the cards, such that you are taking expression of the original author's creativity, that might infringe, even if you change the words used) Whether an element of the game is protected by copyright is a fact-intensive question that would depend on the specifics of the game. Whether your copy infringes is likewise a fact-intensive question that would depend on what you copy. Fair use is also a fact-intensive, case-by-case analysis, but in my opinion, it is likely that creating a computer program derivative work (17 U.S.C. §101) of the game for your own personal education would be considered fair use. From a practical standpoint, even if it were not fair use, it would be near impossible for the copyright owner to discover. Posting the code on GitHub tips the scales away from fair use because of (17 U.S.C. §107(4)): "the effect of the use upon the potential market for or value of the copyrighted work." But, none of the factors are determinative on their own. You ask: I likely cannot simply change all the names of the various cards to something else, right? I agree. In my opinion, the selection and arrangement of the effects attributed to each card is an expression of the author's creativity, and no matter what you call the cards, copyright in the game would be implicated if you retained the effects associated with each card. If I start changing the rules of the game, does that make it legal for me to share my source code, for instance? At some point, it will be an entirely different game, so certainly, in the limit, your work would not be infringing. We can't answer where that line is, but in general, the less of the original author's creativity that you re-use, the less likely a ruling of infringement. Also, in general, the more transformative your work is, the more likely a fair use exception would apply.
Alice has been developing her own enhancements, and they're pretty similar to Bob's. Neither Alice nor Bob has copied the other's enhancements, so neither has violated the other's copyright in the enhancements. Whether that could be proved in court is another matter, of course, but since the original work is licensed under creative commons the question unlikely to arise in court. Would Alice be prevented from coming up with enhancements to her own game if other people could prove they thought of and released the idea first? No. Copyright does not protect ideas. It only protects a particular expression of those ideas from being copied. Theoretically, if two authors come up with identical 500-word descriptions of something and can establish that each did so independently, neither has a claim against the other. The practical problem there, of course, is that it would be impossible to prove such a thing. Could Alice outright claim Bob's "Adapted Material" because he developed it on her original work? Assuming that in publishing his adaptations Bob followed the terms of the creative commons license with respect to the original work, Alice's only claim would be that he copied her adaptations without following the terms of the license. If Bob can show that he did not do so, her claim would fail. In a comment, you wrote: Suppose Alice went ahead and intentionally, somehow provably ripped off Bob's "Adapted Material" because she liked the content so much, does Bob reserve any rights on his adaptation, or is Alice able to commercialize the work that Bob did in extending her original work? If we assume that Bob complied with the license of the original material, we know that he licensed his adaptations under "the identical terms," so Alice would be able to use Bob's adaptations under those terms for non-commercial purposes. Since the assumption here is that Alice provably copied something of Bob's, I think it is fairly clear that she would be liable for damages if she exploited that material commercially without paying royalties.
Making the game free makes very little if any difference to the position here. There are two kinds of IP issues that could possibly be involved: copyright and trademark. Note: both copyright and trademark are civil, not criminal issues (except in very limited circumstances which do not apply to the situation described in the question). You will not &quot;face charges&quot; but might possibly be sued. If you are asked to take down such a game and comply, this might end the matter, but if an IP holder claimed that damages had occurred before the game was taken down a suite might possibly still be brought against the developer. Copyright Names, like titles and other short phrases, cannot be protected by copyright. As long as no other text from anyone else, and no images are copied or imitated, copyright is not infringed. This means that there are no copyright issues. Game mechanics and rules cannot be copyrighted, although the words of game rules can be. Therefore, fair use which is a strictly US copyright legal concept, is not involved here. Neither is fair dealing, a somewhat similar legal concept from the UK and some commonwealth and European countries. Trademark Here is the main issue for this situation. The names of individual Pokémon characters are probably (almost surely) protected as trademarks. That means you cannot use them to identify your game, or any other product or service, and you cannot use them to advertise or market your game. This is true even if the &quot;selling price&quot; is $0. The use here does not seem to be nominative use, as you are not intending to refer to Pokémon or any of its variants. You are just reusing the names. As long as you make it very clear that your game is not made by, nor in any way authorized or endorsed by the makers of Pokémon, this is probably not trademark infringement. But if the makers of Pokémon become aware of your game, they might well send you a cease and desist letter, and they might file a trademark infringement suit. Even if you were to win such a suit, as I think you might well do, it might be costly to defend. Could you alter the names to ones you invent form yourself? That might save a lot of trouble and hassle. What is the value to you in reusing the well-known Pokémon names?
No, this is not true. Copyright can be enforced selectively. You are confusing copyright with trademark. Company can lose its trademark if they aren't protecting it. All the meanwhile they can choose to ignore some copyright infringement while enforcing their rights on others with no legal problems what-so-ever. In order to illustrate the difference: for example, if someone would make a clone of Super Mario and would call their clone as well "Super Mario" and maybe even would call themselves "Nintendo", even if they have programmed the whole game by themselves from scratch and the art and music would be all different, they wouldn't be infringing the copyright but challenging protected trademarks. In your case, the naming was identical, the art and everything was too similar to the original and therefore the clone was challenging the trademark that needs constant protecting.
This can't be right. If I modify open source code as part of the work done, by nature of the open source license that code can not become intellectual property of the client. Certainly it can. That which is "developed or produced" would be the modifications to the pre-existing code, i.e the copyright on the derivative work so created. If the base code was under a share-alike or copy-left license, then the client can only distribute it under the same license (or a compatible one, perhaps). But nothing compels the client to distribute it, and for the client's use, the client owns the copyright, without fear of any future claims by the contractor. If I have my own code/scripts/settings/templates/etc that I use as a contractor, and I modify those in the interest of coding efficiency in the interest of serving the client, it hardly seems correct that these assets become property of the Client. Those are your work, and you can choose whether to sell the copyrights to the client or not. Again, only the work done for that client would be covered under the wording quoted above, unless there is another provision that grants the client a license to use the pre-existing work which you modified for the job, which there probably ought to be. Or I suppose the agreement could assign copyrights in pre-existing work to the client, but that seems an odd choice, and the language in the question would not do that. You and the client could agree on a different provision such as: The contractor grants to the client a fully-paid, non-exclusive permanent license to use all intellectual property developed under this agreement, and any pre-existing works that may be incorporated therein. The contractor warrants that s/he is entitled to grant such license, without infringing on the intellectual property of any other person or entity. That wording would have the contractor retain all copyrights and other IP, but provide a license to the client to use it without further payment or expiration. Many other ways to structure such a provision are possible, dividing the rights up however the contractor and client can agree. The price for the work might vary depending on what rights the client obtains. Both forms, and many others, are perfectly legal, it is just a question of what the contractor chooses to sell, and what th4e client chooses to buy.
As you've presented them, I doubt the functions are protected by copyright in the first place. Originality is one of the threshold requirements for copyright protection, and it demands that the work in question be independently created by the author, and that it possess some minimal degree of creativity. If you're talking about programming at a level so basic that the function truly must be created in a particular way, there is no originality in simply following the instructions. And even if there's some wiggle room, but the language you used has likely been independently replicated by many programmers, that's still not original enough to be copyrightable. What you want to watch out for, though, is the possibility that they've been combined into an original arrangement that is protected. I don't know enough about how copyright law is applied to code to say where or how that line is drawn, but my instinct would be that it could be a fairly low threshold.
No. GPL works are copyrighted (as are most creative works basically everywhere in the world, as soon as they're created, whether or not the author does anything about it), and copyright is what gives the GPL "teeth". Without copyright, you would generally be able to duplicate and distribute programs without any kind of license or permission from the author. Copyright law restricts your ability to do those things. The GPL is a license, which means it's a grant of permission. It says that you may copy and modify and do other things, provided that you comply with the other provisions set out in the license. Quoting from the GPL v3: You are not required to accept this License in order to receive or run a copy of the Program. [...] However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. So if you were to distribute some GPL-licensed software in a way that didn't comply with the terms of the license, the legal framework that would allow someone to sue you to stop you doing that would be copyright law.
A document can be distributed under more than one license. Just because it has been made available under a CC license for free, doesn't mean that IEEE can't negotiate a different license with different terms that allow them to sell the content. (This is similar to the way that a software library can be available for free under a license that permits non-commercial use, but also be made available for a fee for commercial use.) If you want to know whether IEEE is legally selling Aaron Swartz's manuscript, you can contact Morgan &amp; Claypool, the publisher that owns the copyright, and ask them whether this use by IEEE has been authorized by them. For the other documents you mention, contact MIT Press. Etc.