Hello everybody!
I’m new here and this is my first post.
The question is (as you might think) how to protect the game and its idea.
I read, that I’ll get the copyright (more or less), as soon as I start developing my game.
Is that right and is that enough to protect my game?
How do I “present” the copyright?
Now it is at the top of every file in the project.
Lukas
Under the Berne Convention, which pretty much the whole modern world is signatory to, anything you write is automatically copyrighted to you, with no extra steps needed. If you want to open source it, simply pick a license from somewhere like opensource.org, stick it in a file called LICENSE in the source, and you’re done. If you’re not open-sourcing it, then just don’t distribute the source and you’re all set. Stick your name in the credits and title screen if you like, it certainly isn’t required though.
Thanks spog I was going to ask this eventually
Note that you cannot copyright the “idea” of the game.
Cas 
Thank you guys!
This was/is very important for me and (i think) also for other developers! 
You cannot use exactly the same license for the code, the separate documentation and the artworks. For example, my source code is under GPL v2 and most of my artworks are under Artistic License 2.0 or Creative Commons BY-SA.
“cannot”? While it may not always be appropriate, there’s nothing stopping you doing so. I’m also intrigued why you chose the Artistic License for artworks?
You’re right…
I was not accurate enough. Some of “my” artworks reuse parts of artworks created by other people; in these cases, I usually use the same license. It’s even more true when I reuse an unchanged creation, I don’t modify the license.
To expand on this, you automatically have the copyright long as you can prove you created the work, which usually is trivial if you have all the intermediate steps (project files, beta versions, art sketches, design documents).
So always keep a backup of the stuff, just in case someone decides to challenge your copyright or something.
I’m not sure, but I think you can take an extra step to make the copyright more official by registering the property. Not sure how it works exactly.
And it bears repeating, you can copyright content, not ideas. Don’t make a fuss when you publish your sewing/spelunking simulator and someone comes around an publishes a different game with the same mechanic (lots of people misunderstand this)
Thank you for the answers!
Well, if I’m going to use a library or something else (lets say Slick2D, LWJGL, etc…), what should I do to be on the right side?
I don’t want to get problems with them (needless to say). ;D
Copyright is automatic if you can prove you made the work.
However, you can’t take someone to court over a copyright violation until you register it.
when using librarys from others, one always have to look under which license they are distributed. Most of the time you will find a well known open source license which have all some different restrictions how you are allowed to use them. One might only allow you to use the library if you also open source your project, others might only need you to tell people that you used library X which was created by Y and so on.
So always look out which kind of license a library you want to use has.
Another interesting thing about copyright laws, they differ a lot from country to country. And I think one thing about the Berne Convetion says something about that that always the copyright law of the country of the author applys.
So when you use some open source work of mine, for example. Germany copyright law would apply to how you want to use it. And the German laws are quite different then the US ones, giving the author more powers. A author can not lose or give away his “copyright” for example in germany.
This means for example that some Contributor License which forces a constributor to give away his copyright to the original author would be void in germany.
It is also important to note that legal advise gained from public forums is not always reliable.
Cheers,
Kev
^ +1
Just like Wikipedia, this is an starting point, you (we) need to do the legwork and investigate the issue.
In many countries you don’t need to register to take legal action. Its all part of the Bern convention. Of course even for blizzard legal action is pretty expensive, so for the rest of us its unlikely to ever be worth it. However a somewhat unfriendly letter from a lawyer is usually enough for most cases. These are not so expensive.