Can ZDoom be used to make commercial indie games?

[SweatyGremlins]

Hey guys, might sound a bit tasteless but I was thinking about this while on the toilet.

The Indie market is doing pretty well but the FPS genre isn't getting much love (hell even the AAA titles have been stinky). Using ZDoom and Doombuilder someone could make a very fun, fluid FPS in a relatively small amount of time.

Is there any legal reason why people aren't doing this?


I would love to see classic FPS games return, there's all this love for retro platformers right now but when it comes to games like Doom people are often pretty narrow minded and ignorant, calling it dumb and mindless.

I miss FPS games without long scripted sequences :\

[Grazza]

The Zdoom license is a problem in this respect, I'm afraid.

With a GPL-licensed engine, you can make a commercial game as long as everything in your iwad is your own creation (or suitably licensed to allow you to use it in this way), and the game doesn't require any resources from the original Doom games.

But Zdoom isn't GPL, so you are SOL.

SweatyGremlins said:

Using ZDoom and Doombuilder someone could make a very fun, fluid FPS in a relatively small amount of time.

You may be underestimating the time needed to create all the resources. Even making just a few sprites from scratch is a complex undertaking.

[SweatyGremlins]

Oh too bad, i'v seen some great content made using the various ports of Doom, I'm a bit surprised the Doom ports don't allow people to use them outside of hobby use, but I don't have any real understanding of software law\licensing.

I know it's a lot of work to make even simple games, but they would have such a solid base using Doom, I just wanna see a revival of 90s shooters :D

[Grazza]

SweatyGremlins said:

I'm a bit surprised the Doom ports don't allow people to use them outside of hobby use

Some ports do, and others don't, and it depends on which license they are under.

The Doom source code was released twice, with the second time being under the GPL (the initial release did not allow commercial use). That's why source ports can be GPL or not, depending on what they were based on, and which other ports they have taken code from. The GPL license specifically guarantees the right to sell a GPL project, together with material created for it.

If your project doesn't require Zdoom features, then there are ports that would allow you to do what you ask about.

Of course, a GPL version of GZDoom would give you the option of using Zdoom features too, but that doesn't exist as yet. Some discussion here.

[SweatyGremlins]

Yeah I just read up a bit on the wiki that there are two licenses for the Doom source.

From the wiki it says Eternity uses a GPL license, assuming that's correct then the dev team would just have to make their own IWAD with original content and they would be safe right?

I did find an indie FPS called 8bit Killer

http://www.locomalito.com/8bit_killer.php

It looks great but it plays more like Wolfenstein, I also found a game based on the Quake port Darkplaces but I couldn't get it to work.

http://www.retroblazer.com/

[GreyGhost]

SweatyGremlins said:

Yeah I just read up a bit on the wiki that there are two licenses for the Doom source.

Some ports have also borrowed code from other 3D engines (such as Ken Silverman's Build engine), which means they have to acknowledge and work within the limits of whatever license that code was released under.

[Gez]

There was a commercial indie game for ZDoom, but it was only half-commercial. Action Doom 2: Urban Brawl. The IWAD was available for free from the site, but you could buy a deluxe version with bonus maps that was shipped to you on a disc in a case. Once all the printed copies were sold out, the bonus maps became free download as well.

Some people have wondered whether it complied with the non-commercial licenses of the executable or not. Nobody made a lawsuit, however.

I guess if you only sell an IWAD and have an installer that automatically downloads ZDoom from a place where it's freely available, nobody will be able to object. After all, Doom and the rest are still commercially sold IWADs.

[printz]

Grazza said:

With a GPL-licensed engine, you can make a commercial game as long as everything in your iwad is your own creation (or suitably licensed to allow you to use it in this way), and the game doesn't require any resources from the original Doom games.

So, you can sell with a GPL-licensed engine? That sounds okay, as long as the artistic resources (including maps) are available commercially only. Because, if you'd sell just the GPL executable (+ source code), wouldn't someone else be able to simply recompile it, make it their fork, and upload that for free, legally? You'll no longer make much money from that software because someone else will upload it for free.

[Gez]

You can sell a GPL executable.

You just have to provide the source code free of charges. The compiled product does not have to be gratis.

And yeah, someone is perfectly able to get the free source code from you, compile it themselves, and be your competitor. This is something that is entirely intended to be possible; and it has happened several times already. Just look at Linux distros: plenty of them were forks of a previous distro; e.g. Debian->Ubuntu->Mint or RedHat->Mandrake->Mandriva.

[Jon]

SweatyGremlins said:

Yeah I just read up a bit on the wiki that there are two licenses for the Doom source.

From the wiki it says Eternity uses a GPL license, assuming that's correct then the dev team would just have to make their own IWAD with original content and they would be safe right?

You could base your IWAD on freedoom. In fact there are several prboom + Freedoom apps in the iOS app store, for example.

[printz]

But how would I license the resources (maps+multimedia) to make sure they're not free and up for grabs like the source code? [similar to how Doom works].

Too bad that they cannot be DRMed, because people would be easily able to read the open source code and know how to decrypt them. It would be sad to get only 1 buyer, who would afterwards spread the resource file to everyone.

[Phml]

Too bad that they cannot be DRMed, because people would be easily able to read the open source code and know how to decrypt them. It would be sad to get only 1 buyer, who would afterwards spread the resource file to everyone.

If you look at what big corporations are doing, even investing millions into anti-piracy still results in your stuff being cracked before release. As an indie you can't really afford to spend resources and time into anti-piracy measures, and besides advertising your stuff as entirely DRM-free tends to earn a lot of good will.

[printz]

Your argument sounds convincing and sorry I thought that way.