You absolutely can sell a game with CC-BY-SA art in it, but said art would have to keep its license -- whoever buys the game must be able to extract the art and reuse it freely, according to the same terms.

Huh, good question. I'm not certain, actually.

Technically, the CC licenses prohibit you from putting the content under DRM, or other hindrances to copying. I'm not sure if the content being inside a Flash file qualifies. On the one hand, there are tools to extract the media from SWFs. On the other hand, that requires a certain level of expertise. It could be taken either way, I think, but IANAL.

But! Remember that the only person who can complain about it is the author of the original art, and around here we tend to assume good faith. (Right? RIght?! I hope so!) So clearly stating the license, with a link to the source of your assets, is a huge step towards demonstrating good faith. It would certainly be enough for me. And if in doubt, ask for permission. But don't let doubt get in the way of your creativity.

I don't know how Flash SWFs work - but if it's simply like a "bundle" or a different file format, I don't think that would be an issue. Otherwise CC licences would be a problem for all sorts of formats (zip files, installer archives, packages like .deb on Debian or .apk on Android).

CC gives some info at http://wiki.creativecommons.org/License_Versions#Application_of_effectiv... and http://wiki.creativecommons.org/Frequently_Asked_Questions#Can_I_use_eff... .

A key point is "A technological measure is considered an ETM if circumventing it carries penalties under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, or similar international agreements."

So the problem with DRM is either the user can't get exercise their rights, or doing so would be illegal in some countries.

As long as extracting it isn't covered by this, I don't think it matters that it requires some expertise.

Is this the only issue i could encounter with cc Licenses? 

Can i use CC-BY-SA safely in android games?

Most Items i use from oga are CC-BY so whats exactly the difference between CC-BY and CC0 where could i run in trouble and what do i need to look out for?

If you're ok with a cut and paste job, here's my thoughts on this one as posted to another recent thread on the topic:

CC-BY license has a prohibition on using 'technilogical measures' to restrict distribution.  This is a widely interpretted as a restriction on using CC-BY work on games that are sold/distributed on platforms that require/use DRM.  There's alot of debate on what constitutes DRM and which platforms use or don't use DRM, so generally I would advise you to avoid CC-BY works unless you are distributing a DRM-free PC game (eg. a game where you directly distribute a .exe installer yourself either on your own web site or on a DRM-free store like itch.io, etc).   But that's my 'better safe than sorry' advise, not everyone agrees with it ;)

CC-SA license shares CC-BY's anti-DRM clause but also requires you to re-share any derivative artwork you make under the same license.  I'd encourage you to do this anyway no matter which license the source work uses, it's the best way to say 'thank you' to the artists that posted the original work(s).  Note that you don't need to re-share EVERY derivative work you make, the restriction is actually just that IF you distribute derivative work you must do so under the same license.  So, if you make derivative work and distribute it as part of your game you must license the derivative artwork as CC-BY.  But if you just make some derivative work and keep it on your own hard drive, you don't have to share it.

GPL 2.0/3.0 licenses are also subject a good bit of debate as to what they limit/don't limit you from doing and if they do/don't require you to distribute your game source code.  Generally, I would advise you stear clear of them unless you are explicitly making an Open Source game.

OGA-BY is a new license created by this site with the explicit intent of being CC-BY w/o the 'technical measures' clause.  So works under this license are generally safe to use so long as you credit the original artist.

CC0 is essentially public domain.  Works under this license are absolutely free to use as you please, although it's still a good idea to credit the original artists (unless they explicitly ask not to be credited!)

So my 'better than sorry' summary would be, for commercial work, stick to CC0 and OGA-BY works.  For open source stuff, no limits!  Again, that's just my opinion on the matter, not everyone agrees.

>Technically, the CC licenses prohibit you from putting the content under DRM, or other hindrances to copying.

I believe you can circumvent DRM by including an option inside your game, which would allow uploading CC content to say user specified FTP or a USB stick. Code running under DRM has Internet access so it can do anything it wants.

>I'd encourage you to do this anyway no matter which license the source work uses, it's the best way to say 'thank you' to the artists that posted the original work(s).  

A lot of authors employ CC-BY for promotion, so sharing an improved version of their work would only anger them. For example, some artist upload to OGA incomplete (demo version) sprite sheets in hope that people liking them will buy complete package. Such an artist will unlikely be happy if somebody completes his sprite sheet and makes it free.

CC-BY-ND could not be used for trial demo version, because ND clause would disallow incorporating it inside of larger work.

My question was about this line: 

so generally I would advise you to avoid CC-BY works unless you are distributing a DRM-free PC game (eg. a game where you directly distribute a .exe installer yourself either on your own web site or on a DRM-free store like itch.io, etc).

in concern to normal apk packed android games which have the images and stuff not seperately encodet.

@Rainbow Design: I don't know enough about Android development/distibution to really comment on it.  All I can say is I have seen the issue whether Play Store and/or Andriod apk's consitute DRM or not debated on these forums.  That's why I call it my 'better safe than sorry' advice.

The APK distributed on Google Play is the same one I distribute on standalone sites. You can use DRM on Android if you want ( https://source.android.com/devices/drm.html ) but it is not standard.

The APK format is just a zip - you can happily open the archive with any zip extractor. Whilst Article 11 of the WIPO Copyright Treaty may be unclear as to what exactly technological measures are, I don't see that opening a zip/apk file would be breaking laws like the DMCA (or if it is, then CC licences aren't safe for any archives on any platform).