Well, got one vote of confidence from a new-comer:

http://opengameart.org/forumtopic/use-the-art-here-for-my-game

Any other bites on this one?  Was hoping to hear from some of the old timers.  We see alot of license issues on this site, so anyone who's been through a few care to comment?  Is this language clear enough?  Is it too verbose?  Does it seem like it would help clarify things and help prevent at least some of the most common mistakes or misunderstandings we see come through here?

Thanks for the feedback!

You are 100% right about the GPL language, it's not clear and it doesn't really answer the question 'can I use this work in a commercial game?'

What can I say, I guess I hedged.  Truth is, I'm not actually sure if it's ok to use GPL stuff in a commercial project, or rather I should say a closed source project.  I feel like I've seen it argued both ways around here.  Personally, I feel like I would not recommend anyone do it because it feels like inviting trouble, but that's just kind of my gut feeling on the matter and I didn't want to base the FAQ entry on that.  

I guess we should either come to a firm answer as to whether using GPL stuff with closed source is OK (and what the conditions on doing that are) or try a more strongly worded warning 'Use with commercial and/or closed sourced projects is not recommended.'

Gnu does seem to have some info out there for how they envision the GPL to apply to art:

http://gnuart.org/english/gnugpl.html#SEC5

http://www.gnu.org/licenses/gpl-faq.en.html#WhatCaseIsOutputGPL

http://www.gnu.org/licenses/gpl-faq.en.html#GPLOtherThanSoftware

But it's not much help, I couldn't find the 'art does not trigger the linking requirement' 

Also, I've always thought the FAQ got the phrasing wrong on the GPL/LGPL bit.  Doesn't it make more sense as:

"Since the FSF has clarified that use of art does not trigger the GPL's linking requirement, the GPL is effectively the same as the LGPL when used for art."

Well, at least that would make more sense to me since it's saying the /more/ restrictive license is the same as the /less/ restrictive license in the case of art.  Also, since GPL is supported by the site, and LGPL is not, it would seem more sensible to have a statement about what the GPL is, rather than what the LGPL is.  Or is the that whole bit just there to explain why the LGPL is not supported? 

lol, no problem, and very glad you found my write up useful, you seriously just made it all worth while! :)

Now if this post could just catch the attention of some of the admins... ;)

@mdwh:

Thanks very much the feedback!  I am very worried about this thread falling off the radar and I do think it's important to get this stuff updated and correct, or at least as correct as we can get it.

Some itemized thoughts:

> 'Popular' 

I have no problem removing this, although I do think it does serve a purpose.  The idea is to alert folks that DRM is commonly used in game distribution and not just some obscure feature used in a few specialized places.  Also, I don't think the word 'popular' truly constitutes peacocking here as it's pretty well an objective fact that the listed distribution services (XBL, PSN, iOS) are 'popular' by just about any definition of the word.

However, I do agree it's not the place of OGA to try in anyway to advocate for one distribution network over another and since the text does enumerate the 'popular' services, I don't think it's a big deal to drop the word 'popular' on the off chance someone might read it as an endorsement one way or the other.

> 'Google Play, DRM is only enabled if the developer wants DRM. The current wording makes it sound like DRM would be enforced if you happened to package the game in a particular way, even if you didn't want it. I'm not aware that Steam is different. I'd suggest scrapping this bit completely unless someone can show DRM might be forced on developers in some cases.'

Sorry, yeah this is not meant to imply that DRM maybe forced on a package, merely that DRM is an option on these networks.  Does this phrasing clarify that:

"may or may not use DRM depending on how a developer chooses to package a particular game (ex. Steam, Google Android)."

> 'A more general point to say instead, for the point of view of artists wanting their art used in games, is that some commercial companies will want to use DRM'

If you're talking about this as a different approach to the entire section, I agree it's another way of phrasing it and a correct one, but I think it's a little too general.

I think it's important to name a few names and directly list the 'popular' distribution services and make it clear where they fall in terms of the license.   Otherwise, the very next question anyone is going to ask is 'Ok, so can I use this work with my game on XYZ distribution service?'  In fact, this is a question I see asked all the time around OGA, so the goal here is to help answer that question up front for people.  And I think the question works the other way too, for folks submitting work, it's good for them to hear how the license impacts the potential for their work to distributed (and seen!) on the different distribution services.  Again, the goal not being to advocate for one platform or another (or for DRM or no-DRM) but just to help inform people about how the platforms and licenses intersect.

> ' 'additional restictions' (ie. DRM)'

Yes.  Since the point of the OGA-BY was explicitly to remove the DRM restriction, my mind went to 'ie.', but you're right, I think an 'eg.' would be more correct here. So:

' 'additional restictions' (eg. DRM)'

Does that work?

> It might be worth mentioning that OGA-BY can be relicensed as CC-BY (this is useful for anyone worried about licence compatibility/proliferation, or sticking to more well known licences or those approved by OSI, FSF, Debian, etc).'

I'd prefer to leave any mention of re-licensing out of this part of the FAQ.  I just think it opens a whole other can of worms that's best left for another part of the docs.

@mdwh & DezrasDragons:

> Whilst I would hope this is the case (if not, it makes CC BY-SA useless for most games, commercial or open source), unless we have a reference from creative commons or a legal opinion, I'm not sure this is known?

hmm... Yeah, you make me wish I knew where I'd read that because re-reading the license now, it seems pretty clear to me that a video game would constitute a 'Derivative Work'.

About 'Collective Work', by my reading all they mean by 'Collective Work' is anthologies, clip art collections, font packs, etc.  Stuff where you're just bundling up a bunch of works and re-distributing them.  I don't think a video game falls in this category, because it does not present the works independently from one another.  Although, this category does seem to include using images in a book:

 https://en.wikipedia.org/wiki/Creative_Commons_license#Drauglis_v._Kappa...

Which is somewhat analogous to sprites in a video game.

The CC Faq does attempt to address when a work constitutes an adaptation:

https://wiki.creativecommons.org/index.php/Frequently_Asked_Questions#Wh...

But it begins with the line: 'Whether a modification of licensed material is considered an adaptation for the purpose of CC licenses depends primarily on the applicable copyright law.'  Which certainly sets off some warning bells for me! :)

It does go on to say: 'Generally, a modification rises to the level of an adaptation under copyright law when the modified work is based on the prior work but manifests sufficient new creativity to be copyrightable, such as a translation of a novel from one language to another, or the creation of a screenplay based on a novel.'

Hard to say if using sprites in a video game meets that bar or not.  I can say, I personally would not chance it.  That is to say, if I was working on a closed source (or otherwise non-CC-SA licensed) work, I don't think I would use CC-SA stuff with it.

The closest 'art' analogy I could think of would be a collage.  Do collages count as 'derivative' or 'collective' works?  

Found at least one site that defines collage as clearly derivative and states:

http://www.funnystrange.com/copyright/derivative.htm

'Most important to the collage artist is that a derivative work can only include copyrighted material if it is created by the owner of the copyright on the original material, or with that person's permission. This means that making a collage that includes photos from National Geographic, Rand McNally maps, or pictures of Andy Warhol paintings, is illegal unless you have obtained permission from whoever owns the copyright on those works.'

hmm... Anyone out there want to argue the other side of this?

>  I would interpret this to mean that the "slash SFX / slash sprite" combination is a derivative of the SFX, and must be released under a compatible license.

Yeah, this is exactly how I'd interpret that also.  The FAQ linked above) also goes out of it's way to re-state this point, 'synching' is always considered a derivative work.

@DARKAGEGAMES:  Thanks!  Just by reading the post and commenting that it was helpful you've already helped out plenty! :)

@DezrasDragons:

About the legal advice bit, the opening paragraph I've proposed is:

Below are summary descriptions of the licenses supported by OGA.  These are provided to help artists and developers familiarize themselves with the broad outlines of each license.  Nothing written here is gaurenteed to be correct or intended to be used as legal advice.  Please read the complete text of each license before using it for a submission or using a work submitted under that license.

Does that cover your 'not legal advice' concerns ok?

thanks again to all for the feedback!   Will bundle it all up and post back an update to the whole thing shortly.

@DezrasDragons:

> Regarding the collage, I think the question is more whether or not the resulting collage needs to be released under -SA, given that it uses -SA images. If the images in the collage are unaltered, and simply displayed, it seems more like a collective work than a derivative to me.

The jist I got from the article was that using images in a collage is considered a copyright violation, but I guess you're right, that doesn't really address something like the CC-SA license.

Too bad the lengthy paper doesn't really delve into CC issue :(

Googling, I did find this question:

http://gamedev.stackexchange.com/questions/92536/is-it-legal-to-use-crea...

The last answer for which states:

'In short, if you use a CC-BY-SA licensed image to make a video game, the game can be commercial but it should also carry the same license, which means its source and other materials should also be available for others to use under the same terms.'

But again, I'd swear I've seen it argued the other way around here.  Indeed, the OGA site FAQ, though it doesn't explicitly say so, does sort of implicitly endorse the view that CC-SA does not require an entire project to become CC-SA, since it describes the CC-SA license as:

'This license requires you to release any modifications you make to the art work in question under the same license.'

I guess it kind of gets at what a creator is trying to ensure gets 'shared alike.'

If an artist submits a sprite sheet as CC-SA, do they want any games that use those sprites to be shared as CC-SA or do they only care about derivatives of the sprites themselves being shared as CC-SA?

From my reading, it seems like CC folks are after the broader definition.  

I have gone ahead and written the CC folks to see if we can get any clarification out of them on this.

I just used the 'Contact Us' button on their web page, so not super hopeful but maybe we'll get something.

@DezrasDragons: Yeah. "discussed to death" is definitely the technical term for it! :)

Hopefully, we can get some clarity from CC on this.  I did get a nice auto-reply message that promised a personal reply in 2-3 days so we can hope!

But if not, maybe we can just go with some suitably cautionary language, eg:

There is considerable debate about whether a video game using a work licensed as CC-SA-3.0 constitutes a 'derived' work or not by the terms of the license.  Until Creative Commons issues a proper clarification on this issue, it is advised that licensees assume a video game (or similar project) would be considered a derived work under the license and therefore be required to be distributed under the same terms (ie. as CC-SA-3.0). 

@Redshrike: You're right, but certainly knowing how CC /intended/ video games to be treated under the license would be helpful.  They may also be able to comment on how well their intent has held up in the courts.

@MedicineStorm: Trying not to get to excited myself (what are the odds they even respond?) but gotta admit I'm definitely very curious to hear what they have to say.

Did some spelunking through their mailing list archives the other day.  Seems like just the place to look to see if they've addressed this question before.  But sadly, the archives are only viewable one month at a time, and they go back to 2009, so it'll take some time to get through them all.

Archives here, if anyone else is interested:

http://lists.ibiblio.org/pipermail/cc-community/

I do think artists intent matters also.   Does an artist want anything done with a work to be released into the commons also, or are they only concerned about more direct revisions to the work itself?   Unfortunately, since CC hasn't clarified the issue, it's really hard to make any assumptions about what an artist intends by selecting the license.

Well, no reply yet, but still hoping.

In the mean time, here's the full text of my email to CC:

To: info@creativecommons.org

Subject: Use of CC-SA-3.0 art in Video Games

Hi,

I am writing for help answering a question for the Open Game Art community, located at:

http://www.opengameart.org

The site houses art (images, sprites, 3D models, music, sfx, etc) for use in video games and related projects under a variety of different open licenses (CC licenses, GPL, etc).

A question that comes up again and again is:

Can I uses XYZ work licensed as CC-SA-3.0 in my closed source video game project?

Put another way:

If I use XYZ work licensed as CC-SA-3.0 in my project, must I also release the project itself (final game, source code, other assets used, etc.) as CC-SA-3.0?

Put into the terms of the CC-SA-3.0 license itself:

Does using a work (image, sound effect, song, etc.) in a video game constitute an 'adaptation' as defined CC-SA 3.0 licenses?  

And if so, would a video game using the work be required to be released as CC-SA 3.0?  

And if so, would all the components of the video game (eg. source code, other art assets, etc) be required to be released as CC-BY-SA or would it be sufficient to just release the final completed game package (eg. compiled binaries, windows installer, Android package, etc.) as CC-BY-SA?

Sorry to be asking about the old version of the license, the site is in the process of adding support for the new license versions, but most of the work on there now is under the 3.0 versions, so that's why I ask specifically about those.

Thanks very much for your time!

Looking it over, I kind of abbreviated CC-BY-SA as CC-SA a few times, but hopefully they get the point.

Well, I encourage anyone else to write them asking them the same question, maybe if we throw enough rocks one might get through.* ;)

* just to be clear, that's a Tragically Hip reference not an endorsement of throwing rocks! :)

hey!  what do you know, I heard back:

The answers to your question all hinge on whether you are creating an adaptation of the BY-SA work. This is a complicated legal question with no black and white answers, which also depends on what jurisdiction you are in. Here is an FAQ from our site about the topic: https://wiki.creativecommons.org/index.php/Frequently_Asked_Questions#Wh...

There is one fairly clear-cut scenario in this though, and that is when you are using BY-SA licensed music and synching it with a moving image. In those cases, what you are creating is an adaptation because it is written into the terms of the CC license. 

Whenever what you have done creates an adaptation, you only have to ShareAlike the adaptation and not anything else that happens to be aggregated with the work. For example, in the scenario above with BY-SA music you would need to ShareAlike the moving image that uses the music, but you could license the source code to the game however you like. 

Sorry for the somewhat complex answer, but this is a tricky area. We can't give legal advice either so unfortunately even with more specific facts, we wouldn't be able to provide complete clarity. Hope this helps at least lead you toward the answers you need. 

Sadly that doesn't really help very much.  I'll try writing back to see if I can get any better clarification, but the vibe I'm getting here is very much 'USE AT YOUR OWN RISK' :(

Yeah, I also found it intersting that they separated the image synched with music from the rest of the project and said only that would need to be released as SA. 

Of course, this still raises it's own issues.  Suppose you take a CC-BY-SA 'jump' sound and use it with a 'CC-BY' sprite.  Now you need to release the sprite as CC-BY-SA but you can't because you don't own the original work.  

Well for the record, here's how I replied, I figured spelling out a specific example might help, guess we'll see!

Thanks very much for your reply!

I definitely understand what a tricky area this can be and do appreciate you taking the time to try and clarify the matter for us some.

May I ask a few follow up questions?

I guess I kept my initial question deliberately broad in order to keep it short and simple, but it maybe it would more helpful if I provide a concrete example.

Suppose an artists creates a PNG w/ multiple images of a cartoon rabbit in various poses (walking, standing, hopping, eating, etc) and releases the PNG under the CC-BY-SA license.

Now a second artist takes the PNG and uses it in their video game 'Run Rabbit Run!'

The 2nd artist makes no changes to the PNG, but loads it and uses it for the main character, showing one pose at time for the rabbit's different movements in the game and all synched with the players input.

Would this constitute an 'Adaptation' under the CC-BY-SA?

Setting aside the legal issues involved, can I ask about the intent of the Creative Commons with regards to use of SA assets in an example like this?

Is this the sort of use the Creative Commons would want to be considered an adaptation?

I ask this not just to side step the legal issues and avoid asking you for legal advice, but because that's actually an important consideration for the OGA community also.  At Open Game Art, we pride ourselves on sharing assets in a way that is legal, moral, and in keeping with the original artists wishes.  We will remove work from the site regardless of the license if an artist requests it.  So sometimes, regardless what the courts say, it's just as important for us to understand what an artist intended when they selected a license.  Of course, to be sure guessing this can be risky game, but certainly it would be helpful for us to know how Creative Commons intends or hopes the license would be interpreted.

Regarding the example of synching music and a moving image, just to 100% clear, this would also apply when using a sound effect licensed as CC-SA also, correct?   So if someone took a 'bunny hop' sound licensed as CC-SA-BY and synched it with a sprite of a bunny hopping in their game, they would need to share the sprite sheet for that as CC-SA-BY also?  but not the entire game (code base, other music, assets, etc.)

Thanks again for your help with this.  These questions have bedeviled our community pretty much from it's start, so it's great to have any clarification or advice that you can provide.

Well, I heard back again today, here's the unedited reply, interested to hear what folks make of it.  To me it still seems like it'd be hard to recommend someone use CC-BY-SA assets with a closed source project.  At the same time, I'm really impressed they've taken the time to reply and do seem genuinely interested in helping us understand the licenses.

Hey Scott,

Thanks for the email. I'm happy to provide my thoughts about these two scenarios, but I should note that my opinion does not necessarily reflect what CC licensors might want or expect. I know that is stating the obvious, but just wanted to point it out since you mentioned wanting to adhere to the original artist's wishes. 

Re: the PNG file example, to me that doesn't sound like an adaptation if they are using the file unmodified. It sounds more like a reproduction, which would just mean that the file itself remains under BY-SA, but the other copyrighted material in the game could be licensed differently. (Note that if the original BY-SA content was a character with existing story lines and character development, then using that character in a new story line likely would be an adaptation.)

Re: the synching example, you're right that it would apply to any musical composition or sound recording, including a sound effect file. The adaptation would be the work that synchronizes that music with a moving image. I don't know enough about the process of game development to know whether the sprite sheet would be the embodiment of that or not. 

Your questions make me wonder if you think there are forms of more generalized guidance from CC that might be useful in this domain. We are currently doing a lot of thinking about projects we will take on for the next couple of years at CC, so I'd be very interested in whether you think there is a need for CC to publish guidance about these sorts of issues. We'd welcome your input on that. 

@mdwh:

> Whether or not games would be covered as derivative works under CC BY SA,

> in neither case would CC BY SA require you to release source code.

I'm just not sure that's the case.  

It's clear using CC-BY-SA assets could compel you to release other game assets as CC-BY-SA (eg. in the case of the synchronized sound).  

It seems possible that using CC-BY-SA assets could compel you to release the entire game as CC-BY-SA (ex. using 'Hoppy Bunny' sprites, where the original artist has created a story line/character portrait to go along with the sprites).

It doesn't seem crystal clear that source code would never be considered part of an adaptation.  I can see where CC is suggesting that source code does not fall under the SA clause, but they also hedge everything they say, and are generally reluctant to give out any absolutes to where I personally could not recommend someone use CC-SA-BY sutff with a closed source project.

re: 'open source' and CC-BY-SA:

Yeah, you raise exactly the issue that jumped out at me, it seems like using CC-BY-SA assets along with anything issued under any other license could be problematic.

@MedicineStorm:

>  Because it is so situationally specific, each artist and each developer have to assess if this

> license is appropriate for their specific project.

I agree, and that certainly is my take away from this in regards to CC-BY-SA.  But at the same time, that really undermines the useful of the license.  The idea of these common licenses is to have some common, well understood terms of use, so each artist and each user don't have to sit down and agree to terms for every project and use.   Put another way, if you have to contact the original artist to know if you can use their stuff in your project, the license has failed.  I mean, all you're doing there is creating a custom license agreement for each work and use, which you could always do anyway, so how has the CC license helped?

btw that's not really a question for you, just an expression of frustration I guess ;)

> re:  SpriteDisplayerPro

Yeah, here you raise an interesting question.  It's clear that the tools you use to create a 'derivative' are not intended to fall under the SA clause.  But are the inputs to those tools subject to the SA clause, or just the final outputs?   I think maybe CC is only after the outputs.  In that case, this would not be the bunny hop sprites, but rather the final video of the bunny hopping to the music.

Viewed through this prism, code would just be one of the many inputs to a 'derivative' and not subject to the SA clause.  

But it's interesting that in their example, CC says you would have to share alike the 'you would need to ShareAlike the moving image that uses the music'.   If they mean the sprites, independent of the rest of the project, then that would be asking for an input.  But it seems to me like what they want is the final creative project.

@all:  I thought the bit in their reply about if you use sprites for 'a character with existing story lines and character development, then using that character in a new story line likely would be an adaptation.' was particularly interesting and seemed to get to the heart of what CC is after with these licenses.

They are trying to protect 'creative' stuff (ideas, characters, stories, etc.) which seems to run a lot deeper and broader than just the mechanical 'sprite sheets and sound effects' that we think of on OGA.  In this way, it makes sense for the license to be broad and even vague in how it defines an 'adaptation', it's a sort of 'you'll know it when you see it' approach.

Again, this makes it very hard to recommend using CC-BY-SA stuff with commercial or closed source projects (or even open source projects for the reasons mdwh raises).

re: MedicineStorm's 'Bunny Hunter' example.  It's interesting to note that if the original artist had added the submission note 'Hoppy Bunny who likes to eat carrots', and you then made a game with Hoppy introducing 'Bunny Hunter' who hunts Hoppy while he tries to eat carrots, then you would be in adaptation territory.

Well, all this taken into account, how's this for a re-write of the CC-BY-SA descrition:

Creative Commons Attribution-Share Alike 3.0 (CC-SA-3.0)

This license is an extension to CC-BY 3.0 which includes provisions stating that derivative works must also be distributed under the same license.  Works released under this license maybe copied, modified, distributed, performed or otherwise used in anyway without asking, subject to following restrictions:

1) You must obey all of the restrictions of the CC-BY 3.0 license (enumerated above (link))

2) If you make derivative works, you must distribute them under the same license (CC-BY-SA-3.0) 

   The definition of a derivative work is not black and white and there is some ambiguity about how the term applies to using art works in a video game or related project.  Creative Commons has attempted to provide some guidance on the issue here (link to https://wiki.creativecommons.org/index.php/Frequently_Asked_Questions#Wh...), however they have yet to provide specific guidance for most common video game use scenarios (eg. using a sprite sheet licensed as CC-BY-SA).  One use case is clear and spelled out explicitly by the CC-SA-BY 3.0 license: if you sychronize a moving image to a piece of music or sound effect licensed as CC-BY-SA 3.0, then you must distribute the resultant work as CC-BY-SA 3.0 also.

If you are using art, that means commercial use is ok, so long as you provide appropriate credit, don't distribute the work in a way that includes DRM, and are prepared (and able) to release your project or parts of it as CC-SA-BY 3.0 should they be deemed to consititute a derivative of the original work.  Those working on projects for which this might be an issue (eg. closed source, commercial or non-CC-BY-SA open source development) are advised to seek qualified legal counsel before using CC-BY-SA 3.0 works in their project.

If you are submitting work, this licenses means people are free to use your work but must credit you as it's author, can not use it on platforms that impose some form of DRM, and must distribute any changes or otherwise derivative works they make under the same license.

Full license text available here (link to http://creativecommons.org/licenses/by-sa/3.0/)

@mdwh:  

> I don't see anything in the licence that compels me to distribute it?

> (If I modify a CC BY-SA asset but don't distribute it, even though the asset is still under CC BY-SA, I'm not required to distribute it to anyone.)

you're right, I think it's a valid point that the license doesn't compel you to do anything, but unless you are creating art for yourself in a vacuum, then it's not really relevant.

Just assume when I say 'the license compels you to distribute as CC-BY-SA' I mean 'IF you chose to distribute, the license compels you to distribute as CC-BY-SA'.

re: source code

I guess I just feel like if we can't define what constitutes an adaption to begin with, then it doesn't seem like a great idea to start supposing about what may or may not be considered part of an adaptation.   

I certainly agree, there seems to be plenty of grounds to suggest that source would not be covered by the SA clause.  On the otherhand, I don't think I could look anybody thinking of using an CC-BY-SA asset in a closed source project in the eye and say 'Yeah that's a great idea!  You should do that!'

Again, just my view of it and I fully admit I lean more towards the cautious side of these things.

I guess for the purposes of the site docs and faq, the issue can be left aside, as it's probably just enough to include a warning that a project, or parts of it, may fall under the SA clause, without delving into what those parts might be.

@mdwh:

> Just to clarify...

Gotcha.

> I agree with that.

Actually, have slept on your arguments for a few days, I think I've not only come around to your point of view on this one, I think it probably is worth adding something in there to address this concern.  Afterall, it is pretty common question around here.  What about adding a line like:

Additionally, Creative Commons has stated that generally souce code for a game would not be considered part of a 'derivative' work and therefore could be used with CC-BY-SA works without itself needing to distributed as CC-BY-SA.

To the 'derivative works' description?

Considering the general caveat to seek legal counsel that follows, I would be comfortable with that.

@all:

Ok, before I repost the whole blob, how's this for a re-write of the GPL section:

GNU GPL 2.0 and GNU GPL 3.0

These licenses were written with source code in mind, and are included on OGA for compatibility with projects that use GPL licenses.

GNU has provided some guidance for how these licenses may apply to art or other 'non-source-code' items here (link to http://www.gnu.org/licenses/gpl-faq.en.html#GPLOtherThanSoftware).

However, they have yet to provide specific guidiance for how the licenses apply in most common video game art use scenarios (eg. using a sprite sheet licensed as GPL 2.0).

If you are using art, use with GPL-licensed projects is ok.  Those working on non-GPL licensed projects (eg. closed source, commercial or non-CC-BY-SA open source development) are advised to seek qualified legal counsel before using GPL 2.0 or GPL 3.0 works in their project.

If you are submitting art, you should use these licenses only if it is part of a bigger project that uses a GPL license and/or you have read the full license and know what you are doing.

Full license texts available here (link to http://www.gnu.org/licenses/gpl-3.0.html and http://www.gnu.org/licenses/gpl-2.0.html)

Hi all!  Just here to prove that I won't let sleeping dogs lie!  :)

Actually, sorry for the long delay, been busy trying to keep my own projects on track, but rest assured this thread is still dear to my heart!   So much so that I recently got back in touch with the folks at CC to help get some of the 'derivative' works questions answered.

I actually spoke with a copyright lawyer at CC on Thursday, she had some interesting things to say.

On the topic of what constitutes a derivative work, she said that so far it's been CC's goal to remain 'agnostic' about the specifics of what makes a derivative work.  Their goal has been to simply mirror what existing copyright law says.  Legally this makes lots of sense as it puts their licenses in line with existing law and increases their chance of holding up in court.  However, as she pointed out (and out myriad of questions illustrate), the problem is that there is very little in the way of litigated/established legal doctrine with regards to what's a derivative vs simple reproduction in the case of video game art and assets.  

An example she gave was using a CC-BY-SA picture in a book.  She said it's well established that simply using a CC-BY-SA picture in a book does not make the book a derivative work.  In an extreme example, taking a CC-BY-SA piciture or set of pictures and extrapolating a detailed story and characters based on the picture(s) might constitute a derivative, but as a general rule, simple using a picture in a book, does not make the book a derivative work.  She said this is a common use case and that it sometimes bothers photographers when their CC-BY-SA works show up in random news articles or blog posts that are not themselves shared as CC-BY-SA but there's nothing to be done about it because this is the established copyright law.

Unfortunately, in the case of video game art, the legal framework is not nearly as established.  So there is no legal precendent to look to for wether using a CC-BY-SA sprite or tile set or jump sound or something in a video game makes the video game a derivative work or not.

The good news is CC is very interested in these questions and in learning about OGA and the questions and concerns we have with their licenses.  I asked if they would be willing to review the wording for the new FAQ and she said certainly, and we agreed to talk again soon so hopefully we can end up with something for the FAQ that'll provide some kind of useful guidance on the subject.

Yay! So glad to see this thread come back to life!

Just to get us back on solid footing and kind of summarize 'the story so far...',
here's an update to my proposed text with all that incorporates all (or most) of the proposed changes/edits and adds mention of the 4.0 versions of the CC licenses. (Plus corrects many more spelling mistakes than I care to admit to ;)

For:

'What do the licenses mean? Explanation of the licenses allowed on OpenGameArt.org'

I suggest the following text:

Below are summary descriptions of the licenses supported by OGA. These are provided to help artists and developers familiarize themselves with the broad outlines of each license. Nothing written here is guaranteed to be correct or intended to be used as legal advice. Please read the complete text of each license before using it for a submission or using a work submitted under that license.

Creative Commons 0 License (CC0)

This license is the creative commons team's equivalent of public domain. Works released under this license maybe copied, modified, distributed, performed or otherwise used in anyway without asking, crediting or notifying the creating artist.

If you are using art, that means commercial use is ok.

If your submitting art, that means you are giving the work to the public domain.

Full license text available here (link to http://creativecommons.org/publicdomain/zero/1.0/)

Creative Commons Attribution Licenses (CC-BY 3.0 and CC-BY 4.0)

Works released under these licenses maybe copied, modified, distributed, performed or otherwise used in anyway without asking, subject to following restrictions:

1) You must state that you have used the work and credit the original artist

Appropriate credit includes providing the title of the work, the name of the creator and attribution parties, a copyright notice, a license notice, a disclaimer notice, and a link to the material.

2) You must indicate if you have made changes to the work

3) You may not impose any additional restrictions on the redistribution of the work

In practice, this means the work may not be not used on distribution networks that use some form of 'Digital Rights Management' (DRM).

If you are using art, that means commercial use is ok, so long as you provide appropriate credit and don't distribute the work in a way that includes DRM.

If you are submitting work, these licenses means people are free to use your work but must credit you as it's author and can not use it on platforms that impose some form of DRM.

Note that many game distribution networks do use DRM (ie. Apple iOS, Xbox Live, Sony PSN) and others may or may not use DRM depending on how a developer chooses to package a particular game (ex. Steam, Google Android).

Full license texts available here CC-BY-3.0(link to http://creativecommons.org/licenses/by/3.0/), CC-BY-4.0 (link to http://creativecommons.org/licenses/by/4.0/)

Creative Commons Attribution-Share Alike Licenses (CC-BY-SA 3.0 and CC-BY-SA 4.0)

These licenses are extensions of the CC-BY licenses (CC-BY 3.0 and CC-BY 4.0) which include provisions stating that derivative works must also be distributed under the same license. Works released under this license maybe copied, modified, distributed, performed or otherwise used in anyway without asking, subject to following restrictions:

1) You must obey all of the restrictions of the corresponding CC-BY license (enumerated above (link))

2) If you make derivative works, you must distribute them under the same license (CC-BY-SA 3.0/CC-BY-SA 4.0)

The definition of a derivative work is not black and white and there is some ambiguity about how the term applies to using art works in a video game or related project. Creative Commons has attempted to provide some guidance on the issue here (link to https://wiki.creativecommons.org/index.php/Frequently_Asked_Questions#Wh...), however they have yet to provide specific guidance for most common video game use scenarios (eg. using a sprite sheet licensed as CC-BY-SA). One use case is clear and spelled out explicitly by the CC-SA-BY licenses: if you synchronize a moving image to a piece of music or sound effect licensed as CC-BY-SA, then you must distribute the resultant work as CC-BY-SA also.

If you are using art, that means commercial use is ok, so long as you provide appropriate credit, don't distribute the work in a way that includes DRM, and are prepared (and able) to release your project or parts of it as CC-SA-BY should they be deemed to constitute a derivative of the original work. Those working on projects for which this might be an issue (eg. closed source, commercial or non-CC-BY-SA open source development) are advised to seek qualified legal counsel before using CC-BY-SA 3.0 or CC-BY-SA 4.0 works in their project.

If you are submitting work, this licenses means people are free to use your work but must credit you as it's author, can not use it on platforms that impose some form of DRM, and must distribute any changes or otherwise derivative works they make under the same license.

Full license text available here CC-SA-3.0 (link to http://creativecommons.org/licenses/by-sa/3.0/), CC-SA-4.0 (link to http://creativecommons.org/licenses/by-sa/4.0/)

OGA-BY 3.0 License

This license is a derivative of CC-BY 3.0 which removes the restriction on placing 'additional restrictions' (eg. DRM) on the redistribution of the work. It was created to provide an option for artists wishing to be credited for their work but not wanting to restrict it's distribution on DRM using platforms.

Works released under this license maybe copied, modified, distributed, performed or otherwise used in anyway without asking, subject to following restrictions:

1) You must state that you have used the work and credit the original artist

Appropriate credit includes providing the title of the work, the name of the creator and attribution parties, a copyright notice, a license notice, a disclaimer notice, and a link to the material.

2) You must indicate if you have made changes to the work

If you are using art, that means commercial use is ok, so long as you provide appropriate credit.

If you are submitting work, this licenses means people are free to use your work but must credit you as it's author.

Full license text available here (link to http://opengameart.org/content/oga-by-30-faq)

GNU GPL 2.0 and GNU GPL 3.0

These licenses were written with source code in mind, and are included on OGA for compatibility with projects that use GPL licenses.

GNU has provided some guidance for how these licenses may apply to art or other 'non-source-code' items here (link to http://www.gnu.org/licenses/gpl-faq.en.html#GPLOtherThanSoftware).

However, they have yet to provide specific guidance for how the licenses apply in most common video game art use scenarios (eg. using a sprite sheet licensed as GPL 2.0).

If you are using art, use with GPL licensed projects is ok. Those working on non-GPL licensed projects (eg. closed source, commercial or non-CC-BY-SA open source development) are advised to seek qualified legal counsel before using GPL 2.0 or GPL 3.0 works in their project.

If you are submitting art, you should use these licenses only if it is part of a bigger project that uses a GPL license and/or you have read the full license and know what you are doing.

Full license texts available here (link to http://www.gnu.org/licenses/gpl-3.0.html and http://www.gnu.org/licenses/gpl-2.0.html)

For:

'I'm a commercial (closed-source) game developer. Can I use this art?'

I suggest the following text:

This depends on the license under which it is submitted. Please see ''What do the licenses mean? Explanation of the licenses allowed on OpenGameArt.org' (link) above for a summary of the supported licenses as well as links to their full text.

Note that if a work is submitted under multiple licenses you may choose which of the selected licenses you wish to use it under.

hmm, sorry the formatting on that didn't come out too great (missing indents and new lines in a few places).   I can never seem to win with OGA's text formatter.

Anyway, naturally I am ok with the proposed changes.  :)

> I wonder if the language proposed for the CC-BY-SA section is really helpful to anyone.

I agree the text is long and leaves the answer ambiguos.  I am open to cutting it down a bit, although I don't know it's really possible to provide much more clarity.  I do think the 'synchronizing sound and video = derivative' is important to keep in there.  I"m not sure what other cases can even be enumerated.  It seems like even with the CC folks involved the conversation just went in circles.

I think the key point to get across is this one:  '[be] prepared (and able) to release your project or parts of it as CC-SA-BY should they be deemed to constitute a derivative of the original work.'

I guess you could read that as being designed to scare people off from using CC-BY-SA stuff, but I really think that's the best advice we can give on the subject.

I know I'm tooting my own horn a bit in saying this but I think this is one where we let the perfect be the enemy of the good.  I know it's important to get this stuff right but on the other hand, even the original proposed text is leagues more helpful than what is currently in the FAQ.

> Does it, though?

How about:

'I'm a commercial (closed-source) game developer. Can I use this art?'

Yes, however there maybe some restrictions and requirements depending upon the license under which it is submitted. Please see ''What do the licenses mean? Explanation of the licenses allowed on OpenGameArt.org' (link) above for a summary of the supported licenses as well as links to their full text.

The main point of this section it just to link folks back to the bigger rundown of all the license, so I don't think that it matters too much how it's worded.

> "don't distribute the work in a way that includes DRM" vs "distribute the work in a way that does not impose DRM"

I don't think it's hugely confusing as is, but I see your point here.  However, could we stick to the word 'include', or perhaps 'use', as in "distribute the work in a way that does not use DRM"?   'Impose' sounds like it's implying a value judgement which (much as I'm sure we'd all like to) should probably avoided.

> "closed source, commercial"

The point of using these terms in this section is not to suggest that problems with CC-BY-SA are exclusive to or arise because of "closed source, commercial" projects.   It's just to highlight the fact that if you are working on a 'closed source, commercial' project than you should seek legal advice before using CC-BY-SA assets.  So you are correct, technically issues arise because of how the assets are used and/or mixed with other assets, the idea here is just to give fair warning that "closed source, commercial" developers should be careful with CC-BY-SA stuff.   Yes, open source projects can also run afoul of CC-BY-SA too, that's why they are also mentioned.  

Put another way, using the key words "closed source, commercial" here is more about making sure that "closed source, commercial" developers hear the message, that's why it's important to call them out by name instead of leaving it at a more general statement.

> I beleive closed/open source doesn't mean closed/open asset.

Yes this is correct but that's why the text just supplies a warning.  It doesn't say you can't use CC-BY-SA stuff for closed or commercial development, it just says you should be sure you know what you are doing if you choose to do that.  

>  'input vs output', 'just the rendering of the two together', 'the compiled game executable itself and not the source code that is the derivative'

First, I think it is VERY important to include this use case example (synchronizing sound and video) in the text because it is so explicitly enumerated in the license text.  It's clear that whatever they meant by this, the CC folks thought it was really important.

Second, my understanding was that everything is output focused.  The CC folks don't care about what tools or other inputs you use and there is no case where the license would claw it's way backward to include other non-CC-BY-SA art used in a project.   So if you combine a CC-BY-SA work with a non-CC-BY-SA work, only the combined work must be distributed as CC-BY-SA.  

Third, yes, I think the CC folks were pretty clear that they did not ever intend source code to be counted as part of a derivative work, only the final compiled game executable.  In their view, source code is viewed as in 'input' like a layered PSD work file or a Blend scene file.

> There are a whole list of examples we can add to help outline what is- as is not- a derivative,

Are there?  Think about how you just picked about the animation with sound example, and that one is specifically spelled out in the license!  And yet still it presents all these ambiguities and questions for us.  I might be wrong, but I just don't know that there are a ton of clear cut and relevant examples out there for us to expound upon for people.

Thinking about this out loud, this is a warning game not an explaining game.  If the definition of a derivative work was clear cut, it'd be easy to just spell it out but since it's not, the best thing we can do is just give a fair warning: read the licenses for yourself, talk to a lawyer, make your own decisions.  Maybe that's not all that useful, but it's all we really have. 

Two things we don't want to do are: 

1) Tell people they are ok to use assets in a way they are not actually ok to use them.

2) Tell people they are not ok to use assets in a way that they are actually ok to use them.

Since the licenses themseleves are not clear about this stuff, I think the best tact is just to say nothing.  Otherwise, no matter what you say, you're taking the risk that it'll turn out to be wrong and then you've been handing out bad advice for however long.

@all:

May I suggest that we move forward with getting the updated license descriptions posted to the site and then work on any other questions/answers we want to update/add/tweak on the FAQ pages?

I don't mean to dismiss anyone else's work (far from it, I'm thrilled to see someone else jumping into the fray here!) but I do have the serious concern that if we start into other FAQ questions now, we'll get lost in the discussion of it all and go another 5 years or more with the current text.

@bluecarrot:

Wow, that's quite a list of questions you're biting off, thanks for taking on the work to do this!
I'll provide specific feedback on whichever thread you end up posting your work to, but I do have one general comment which seems appropriate for this thread:
Won't the answer to several of these questions just be a simple 'Yes', 'No', or 'Maybe', followed by 'See our description of the various license available on OGA' with a link to the proposed text from this thread?

> How should I credit the artist?

One thing I did want to work into the discussion, but have been holding off for fear igniting more discussion and postponing any actual updates to the site, is that we really ought to add a section where we provide a few concrete examples of how to properly credit a work. I've putting an example in the Game Jam descriptions for some time now and I really do think it has helped.

> FSF email

Thanks for taking the time to reach out to them! It's maybe not the answer we were hoping for, but it does provide some clarity in the sense that we can now say for sure that neither the CC nor FSF folks have a ready made answer or test for what constitutes a derivative work. All the more reason we should probably not be trying to provide any tests or answers ourselves.

@all:

On the topic of derivatives, there's another whole side to this that we haven't really discussed and that's what would the original artist consider a derivative work.
While from a purely legal and liability standpoint this question is irrelevant, from a personal and moral standpoint it's actually very important, at least to me (and I'd like to think to the OGA community generally as well).

I know this wading into murkier waters still, but it gets to the original artists intent.

If an artists posts a new tile set under CC-BY-SA it seems safe to assume they are hoping any expansions, edits, etc, to the tile set will also be shared back to the community.

But are they also hoping any games made with the tile set are shared back to the community with an open license?

That doesn't seem as clear. For some folks, the answer is plainly yes, but others might be more interested in seeing the work widely used and only concerned that the aforementioned expansions, edits, etc. are shared back to the community.

Both points of view are valid and if I was using someone's work, I'd want to know which way they felt so I wasn't using their work in a way counter to their intent. What I wouldn't want (and this applies to OGA generally too I think) is for someone to share something and then come to regret it because it was being used in a way they didn't intend. And yes, I know to some extent that's unavoidable, but I still think the point holds, the less 'sharer's remorse' out there the better since that necessarily has a negative impact on people's desire to openly share their work.

One more point I'll add is that it seems really unlikely to me that an artist sharing something under CC-BY-SA doesn't care if you release an entire game using their work under a closed license, but does really really care if you synchronize a sword swooshing sound effect to their sprite's attack animation and release that under a closed license. To me this just shows a way in which the license is out of sync with video game use cases.

Well, all I wanted to do by bringing this up was just point out another way in which CC-BY-SA is murky ground. That's not to say the license isn't useful or important, it's just to further the argument that we should probably give guarded answers about it on the FAQ.