Edit: On the other hand, what is so bad about citing your sources? There is a lot of products in use today that has an "endless" list of legal stuff for using other people's "stuff". If you have an iPhone, for instance, have a look at "Legal Notices" in Settings -> General -> "Legal Notices". Spotify: Help -> Show Licences.

I'd prefer for someone to directly copy and then cite the source vs. copying and trying to modify the code so it doesn't look like the source any more. If you copy something and cite the source, it's not really plagiarism any more, because you're not attempting to make it look like your original work.

Just as a note, copying things from stackoverlflow.com is perfectly safe, since everything you share there get Creative Commons Attribution Share Alike license

If you copy code, it can be "perfectly safe" from any copyright concerns and still be plagiarism.

Moving to business forum.

Plagiarism is a concept in school, so ask your teacher about the policies. In the rest of the real world, it is copyright that concerns us.

Not a lawyer but someone who asked basically the same question to a lawyer...

Copyright is about people and organizations attempting to protect valuable content they have created.

When you get helpful content from a book, website, or other source designed to educate people, double-check the license for the site and content. If the code sample specifically states a copyright notice, such as GPL or BSD or other similar license, follow it. Otherwise use your brains.

When you buy a book or visit a help website, consider: Are they attempting to protect that valuable content? Or are they publicly speaking the content with a clear intent that it be shared and used elsewhere?

There are four factors that go into copyright claims: Purpose and character, nature of the work, substantiality, and effect of the use.

In your case the purpose and character of the original work was to educate people about how to use a concept, the nature of the work has transformed from educational material to a game, the published game might use the entire concept taught but that piece is a tiny part of the game, and the effect of using it in your game is not going to alter the value of the material as it exists in the book or web site.


Unless copyright is specifically claimed in the code sample, it is generally safe to include source code snippits found on educational and tutorial web sites as a small part of a larger product. However, if it specifically does include a notice (like the GPL or BSD license that require every source file be properly marked with a copyright notice) then that applies instead.

I was reading about this on Friday. If you want to avoid copyright infringement you need to do the following:

1) Get a team to look at the API and write a specification document

2) Get lawyers to look over document for any patent/copyright infringements

3) Get a completely different team to implement the specification knowing nothing about the original implementation

I'd like to know where you read that on friday :)..

I've developed software (and music--also great fodder for copyright discussions) for decades, ranging from companies that everyone on the planet has heard of to tiny companies no one ever knew existed.

We never did anything remotely like that "to avoid copyright infringement".

Step 2) there in particular is massively expensive, and I've never known that to be done as a matter of course.

What that does look like is how you might go about reverse-engineering something and be (semi) safe, from a legal perspective (i.e a 'clean room' implementation of an existing piece of software). I don't get the idea that's at all what the original question was about.

Frob (as always) gives great answer.

To avoid copyright infringement, write your own code from scratch.

That said, you can use common sense. If you look up a bubble-sort algorithm in a common textbook and implement it in 'C, you aren't infringing on any copyright.

if you look up something on StackExchange, etc, use it is a reference. If there's not much to the code (aside from simply an example of proper coding or API usage), then copying and altering it is almost certainly fine. That said, don't cut and paste willy-nilly from the internet, unless you are very aware of (and confident in!) the licensees associated with the content.

Frob (as always) gives great answer.

Maybe replace 'always' with 'usually'. :-)

I appreciate being put on a pedestal as much as the next person, but believe me, I make mistakes just like everyone. I try to look things up, speak from experience, and explain my thought processes, but there have been times where things I have posted have contained flaws.

I hope people will call it out if they see something wrong with the posts.

If discussing the ethical aspect of plagiarism (independent of copyright issues), one answer is to put a link in the source code to where you found the solution. This is useful for yourself (if looking at it years later, and you wonder why on earth you put that code there, or what it does), and is also indicating to anyone else reading the source that you're crediting your sources.

Just as a note, copying things from stackoverlflow.com is perfectly safe, since everything you share there get Creative Commons Attribution Share Alike license

I'm sure most sites like it works similarly

Fully understanding any code you include in your project is of course a good idea in general

Careful - CC BY SA would require giving attribution. The "share alike" would also require the source code that references the copied source code (and presumably any compiled binaries) to also be under CC BY SA. This would be a pain for commercial users (who presumably don't want their programs to be freely distributable), and also potentially Open Source (since CC BY SA isn't commonly used for source code, so you'd have to worry about compatibility with licences like GPL, BSD etc).

If you are using code from elsewhere, in my opinion you should be very careful about what the licence is.