Distributing games made with BFW engine commercially?

[Gambit]

The massive problem you're going to run into with your game (even bigger than people compiling your source and selling it on their own) is this:
"Oh look a 2d turn based strategy game for 19.99. What's this? 'Based on Battle For Wesnoth'. Wtf is that? -googles it- Oh that is free... well lets try that instead."


Also you can't sell anything you made with RPG maker 2k3. VX is the first version to allow for commercial games and you have to buy that right (commercial license doesn't come with the $60 regular version) and you can't use any music or sound effects or tilesets or artwork that came with the game or in the rtp. Everything has to be 100% original.


BfW stopped being a game a long time ago. It is a 2d turn based game engine. It just so happens to come with some example campaigns and a default faction already installed.

[CresCoJeff]

It's interesting that you mention RPG Maker because Wesnoth's engine has successfully been used to make RPGs (all free, and on the add-on server): Brotherhood of Light and Wesband are two of the fanciest examples.

Neat, I'll have to take a look at those.

[Zarel]

The massive problem you're going to run into with your game (even bigger than people compiling your source and selling it on their own) is this:
"Oh look a 2d turn based strategy game for 19.99. What's this? 'Based on Battle For Wesnoth'. Wtf is that? -googles it- Oh that is free... well lets try that instead."

1. The GPL does not require that "Based on <source material>" to be included in the packaging (a license.txt somewhere in the game disk is enough).
2. Even if it is, a negligible number of users actually read the fine print.
3. Even if they do, a negligible number of users will look up the source material before buying the product, and refuse to buy the product on the basis that its source material is free.

It's interesting that you mention RPG Maker because Wesnoth's engine has successfully been used to make RPGs (all free, and on the add-on server): Brotherhood of Light and Wesband are two of the fanciest examples.

Quality, on the other hand...

[Aethaeryn]

It's interesting that you mention RPG Maker because Wesnoth's engine has successfully been used to make RPGs (all free, and on the add-on server): Brotherhood of Light and Wesband are two of the fanciest examples.

Quality, on the other hand...

There's a reason why I only named two.

Personally, I'm disappointed there's not more RPGs. Here's one more I just remembered and can recommend (part of it is an RPG): Ooze Mini-Campaign.

[esr]

As others have pointed out, nothing stops you from writing a game, shipping the entire source vode and content under GPL, and trying to sell that. So the real question is whether you can ship a game that adds closed content under a proprietary license to the GPL core.

Note: I am not a lawyer. I am, however, a lay expert on these issues who has instructed lawyers about them more than once.

There are a couple of different subcases here that need to be reasoned about differently. If you're talking about linking closed proprietary C++ code to the core engine, no, you can't do that. This would very clearly create a derived work that falls under GPL terms. But I think that's not the case you're interested in, anyway.

Adding WML/graphics/sound of your own is a different case, When your own add-on WML includes your own sound and graphics, there's no GPL issue. It all turns, really, on whether the WML of a campaign is a "derivative work" of the core Wesnoth content. Specifically, what haopens legally speaking when you write a file include in your code that means core content will be evaluated by the game engine every time yours s.

The answer is: Nobody is sure, because no such question has been tested in court and there is no controlling precedent - nor is there any statute law. Analogies don't take us very far. If you want to argue that file inclusion does not create derivation, you can point out that nobody claims that an application becomes a derivative work of the Linux kernel by making a system call. If you want to argue that it does, most people are sure that static-linking a piece of code to GPLed code creates a derivative work.

There is an ongoing controversy about dynamic linking. The FSF says that if you dynamic-link a piece of code to a GPLed library, it acquires GPLness. Many other people think this is ridiculous. My own opinion is neutral: I think the controversy is an argument for scrapping the GPL - you don't have freedom if the theory of a license makes it impossible to reason about your rights without that kind of hairsplitting. But my opinion isn't the point; the point is that WML file inclusion is rather exactly like dynamic linking through a named interface to a code library whose content is not static but might have changed since the last time you called it

So. Tell me what a court rules about dynamic linking, and I'll instantly tell you whether you can call Wesnoth core WML without being required to GPL your own. Until then, nobody knows. Anybody who claims to know - lawyer or not - is handing you a line of unsupported guff.

[Zarel]

But my opinion isn't the point; the point is that WML file inclusion is rather exactly like dynamic linking through a named interface to a code library whose content is not static but might have changed since the last time you called it

Isn't WML more like, say, a scripting/markup language? I think we can all agree that the licenses of interpreters/compilers do not infect the code they deal with, so the question becomes: Why is WML more like dynamic linking than a scripting language? (I'm not contradicting you; just trying to clarify a point I do not fully understand.)

[AI]

But my opinion isn't the point; the point is that WML file inclusion is rather exactly like dynamic linking through a named interface to a code library whose content is not static but might have changed since the last time you called it

Isn't WML more like, say, a scripting/markup language? I think we can all agree that the licenses of interpreters/compilers do not infect the code they deal with, so the question becomes: Why is WML more like dynamic linking than a scripting language? (I'm not contradicting you; just trying to clarify a point I do not fully understand.)

If you write pure WML, yes, but what esr likened to dynamically linking libraries was using core files and macros. That is, you're using someone else's work, but you're not directly copying it into yours.

[Aethaeryn]

If you write pure WML, yes, but what esr likened to dynamically linking libraries was using core files and macros. That is, you're using someone else's work, but you're not directly copying it into yours.

Yes, using macros or even movetypes in units (since it points to a file with a list of attributes) is including GPL code. It would be hard to write a unit .cfg file that didn't depend on GPL WML.

[Viliam]

I think there are two questions to consider here:

1. If you decide to make some parts of the new game proprietary -- to prevent your first customer giving it legally free to everyone else -- which parts should it be? Text? Music? Pictures? Something else?

2. Based on the previous answer: For your selected "media type" what exactly can you make and what should you avoid to prevent the GPL infection.


For example, if I believe that having proprietary pictures is enough (story intro, terrains, items, units, weapons, portraits), the answer is IMHO simple -- adding new PNG files to the game is not a "derivative work" if my new pictures are not based on existing pictures. And I can still use all the original pictures. So for example I can create a new faction, and let it fight against existing factions.

It would be more difficult to protect WML, because WML files are pieces of code that include each other. It would be also difficult to protect story text e.g. by placing it outside of WML. (Technically, the texts in WML could be named "text0001", "text0002" etc, and then converted to normal texts using translation tools. For example an English "translation" of "text0001" would be "A long time ago in an empire far, far away...".)