How do Creative Commons licences WITHOUT the Share-Alike attribute work? Can derivate works only be more restrictive, or what? I don't understand how CC licenses without the attribute Share-Alike are supposed to work. Ok, you can "share differently", but differently how? You can be more liberal? Doesn't make sense, as this would be equivalent to putting the work into public domain so there would be no point in having this license in the first place,. So you can only "add restrictions", keeping those already there?
From the legal code of the Creative Commons Attribution 4.0 license (emphasis in the original): 1.a Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image. 1.b Adapter's License means the license You apply to Your Copyright and Similar Rights in Your contributions to Adapted Material in accordance with the terms and conditions of this Public License. 1.f Licensed Material means the artistic or literary work, database, or other material to which the Licensor applied this Public License. 2.a Subject to the terms and conditions of this Public License, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to: 2.a.1.A reproduce and Share the Licensed Material, in whole or in part; and 2.a.1.B produce, reproduce, and Share Adapted Material. 2.a.5.B You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material. 3.a.4 If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License. In short, if the original is CC-BY, you can license derivative works under whatever terms you want, so long as the license of the original work is not infringed by the new terms for the derived work. In particular, ordinary copyright (aka. &quot;all rights reserved&quot;) is a perfectly acceptable copyright for a derivative of a CC-BY work (but the original credits should be included -and augmented- in order to also comply with the original CC-BY). Also note this doesn't restrict anybody's rights to use the original material under the original license. The other non-ShareAlike license that permits derivative works (Attribution-Noncommmercial) has a different version of clause 2.a.1.B: produce, reproduce, and Share Adapted Material for NonCommercial purposes only. so any license of a derivative work cannot permit commercial use of the original work. It may be possible to permit commercial use of those portions of the derivative that can be separated from the original; this gets into an extreme edge case of copyright law and you'll probably want to consult a lawyer if you find yourself in such a situation. Another way to consider this issue is by noting that you are only licensing your modifications. For example, if you add a mustache to a CC-BY portrait and use a CC-0 license, only your mustache is CC-0; you can't eliminate the original author's requirement of attribution this way. The derived work would still have to be used under a CC-BY license (or compatible).
When you license your creative work under one non-exclusive license such as CC-BY-SA, you are in no way prevented from also licensing your works under different non-exclusive licenses such as MIT. The other license doesn't even have to be an open source license – dual-licensing is a common business model. You are the sole copyright holder of the creative work. No one else can use your works. By offering licenses, you are giving permissions to other people. But you still retain all your rights. You are not required to comply with these licenses yourself – you are the licensor, not the licensee. Technically, the licensor of CC-BY-SA 4.0 material does give up some rights. For example, you waive the right to collect royalties when recipients exercise the permissions you gave them through this license (cf section 2.b.3). But that doesn't restrict you outside of that license.
Reproducing someone else's copyrighted material without permission is a violation of that copyright. This includes using it to promote your Twitter account. This is a violation of copyright law and of Twitter's TOS. There may be Fair Use exceptions- this question is arguably fair use. However, it's extremely unlikely your intended post counts. In the case of the image in question, royalty-free means you pay for a single licence for that image and can then use it as much as you want (according to that licence). You can post that image in as many of your tweets as you like- you don't have to pay each time. If you don't want to pay for images you use, use public domain images, images with licenses that allow you to use them, or create them yourself.
Copyright never protects ideas or processes, it only protects expression: words, images, and sounds, some of which may describe ideas. But when a work is nothing more than a translation of an idea into words, with no independent originality -- when almost anyone would use more or less the same way to describe the idea, then the work will not be protected by copyright at all, as it is not considered an "original work". Computer code that implements an algorithm often falls under this rule. It is my belief that the code shown in the linked SE thread would fall under this rule, and would not be protected by copyright at all. If this is correct, then anyone may share such a program with no copyright concern.
Let’s work it through Is the work copyright? Yes. Are you making a copy or a derivative work? Yes. Do you have permission? No. At this point, it is prima facie copyright violation. However, various copyright laws have defences for breach. You don’t say where you are but as the USA is the most permissive in this regard we’ll use the USA. If it’s not legal there, it’s not legal anywhere. If it is legal there, it’s still likely to be not legal everywhere else. is it fair use? Almost certainly not. Wizards of the Coast (the copyright owner) already do this. While this service is free for creatures from the Monster Manual, it does drive traffic to their web site where they sell stuff. They also licence (presumably for money) others to do the same. Your usage would negatively affect the copyright owners market. This counts against fair use. Because it’s already being done, your work has virtually nil transformative value. This counts against fair use. You are copying a substantial part of the work. This counts against fair use. You are not using it commercially but neither is it for educational use. This is unlikely to matter. On balance: not fair use. TL;DR This is copyright violation.
Is an article licensed under an Open Access license equivalent to a public domain work? No. Intellectual property practitioners and professors often describe copyright as "a bundle of sticks." This means that intellectual property laws grant the creator of a copyrightable work a large number of rights, and the creator can grant or deny others each of those rights individually. So, for instance, an author can grant a publisher the right to publish his or her book in one country, but not in another, or to copy it verbatim but not to alter it. The purpose of a license, any license, is to specify which of those rights pass to the licensee (the end user) and which stay with the licensor (the creator). This is true of creative commons just as it is for any other license. For example, many open access publishers publish under the Creative Commons CC-BY journal. This is an attribution license; it requires as a term of the license that you give credit to the original creator. This is something you would not have to do with a public domain work. In addition, under CC-BY, you have to include a copy of the license with each copy you distribute, and you cannot add your own copy protection to any copies you distribute. Again, these sort of restrictions do not apply to a public domain work. In short: the purpose of a license--any license--is to define the ways in which you can, or can not, use the licensed materials. Any license that contains any provisions restricting the licensee's use is going to be more restrictive, by definition, than the use of something in the public domain.
Is it ok to copy the game concept and even with mostly similar content like "fighting", "building houses" etc ? Yes, but ... I should also mention that pretty much my whole User Interface is based on the User Interface from "Parallel Kingdoms" Is copyright violation. Ideas are not protected by IP law. The tangible representation of those ideas (art, words, layout, format etc.) is protected.
You can do whatever you like with posts made after you change the rules - you have to leave the previous stuff alone. The contributors' have accepted the terms of the licence: They own the copyright or have permission from the copyright holder to post it (the promise) They agree that it can be edited altered or removed CC-BY-SA allows people to copy the stuff off the website and republish it - this is way outside what the contributors agreed to. These people have given permission for their work to be altered but not copied.