Can you just make game in GZDoom and sell it on steam?

[LukeGaming]

To be honest I'm not sure how to phrase that question and on which sub-forum should I ask.

I know that there is a whole lot of games made using GZDoom on steam:

But I can't fully wrap my head around this - if you make game on GZDoom, can you just post it on steam if you made it out of your own levels and assets? Can it use mechanics from Freedoom in its scripts? How does that work?

[Jayextee]

If you've created every single asset found within the attached .wad or .pk3 files, you absolutely can do this.

 

3 minutes ago, LukeGaming said:

Can it use mechanics from Freedoom in its scripts? How does that work?

Because Freedoom has no mechanics, it's literally just a .wad of said assets, created for free use by the community. The engine (in this case GZDoom) does all the mechanics work.

[Gez]

32 minutes ago, LukeGaming said:

But I can't fully wrap my head around this - if you make game on GZDoom, can you just post it on steam if you made it out of your own levels and assets? Can it use mechanics from Freedoom in its scripts? How does that work?

The GNU Public License explicitly allows commercial use, and so any source port under the GPL can be used to create commercial games.

 

Freedoom does not contain any original game mechanics, because it is designed to work with vanilla Doom which is utterly incapable of running any sort of third-party code. All the mechanics from Freedoom are therefore just the mechanics from Doom, where they were hardcoded into the engine, meaning they're part of the GPL code that can be freely reused in commercial projects.

 

Basically, as long as all the stuff in the .wad or .pk3 files that you distribute are your own, or at least are resources that you have the right to redistribute commercially, then you can sell it on Steam as your own game, bundled with GZDoom. There's just a few files from the GZDoom distribution that you have to remove because they'll be irrelevant to your game and contain assets derived from the original games, like brightmaps or widescreen versions of certain graphics, those are brightmaps.pk3, game_support.pk3, and game_widescreen_gfx.pk3.

[LukeGaming]

1 hour ago, Jayextee said:

If you've created every single asset found within the attached .wad or .pk3 files, you absolutely can do this.

 

Because Freedoom has no mechanics, it's literally just a .wad of said assets, created for free use by the community. The engine (in this case GZDoom) does all the mechanics work.

 

20 minutes ago, Gez said:

The GNU Public License explicitly allows commercial use, and so any source port under the GPL can be used to create commercial games.

 

Freedoom does not contain any original game mechanics, because it is designed to work with vanilla Doom which is utterly incapable of running any sort of third-party code. All the mechanics from Freedoom are therefore just the mechanics from Doom, where they were hardcoded into the engine, meaning they're part of the GPL code that can be freely reused in commercial projects.

 

Basically, as long as all the stuff in the .wad or .pk3 files that you distribute are your own, or at least are resources that you have the right to redistribute commercially, then you can sell it on Steam as your own game, bundled with GZDoom. There's just a few files from the GZDoom distribution that you have to remove because they'll be irrelevant to your game and contain assets derived from the original games, like brightmaps or widescreen versions of certain graphics, those are brightmaps.pk3, game_support.pk3, and game_widescreen_gfx.pk3.

That's neat, thanks for clearing that up!

Edited October 20, 2023 by LukeGaming

[ax34]

Yes, but you can't add DRM to it.

[Graf Zahl]

And of course all altered and added source code needs to be published.

 

[Lofwyr]

By the way, the fact that the GPL requires the source code to be released still does not bar you from selling the access to the source first.

Whatever you distribute just has to have the source provided with it for the end user to have it.

 

You could ransom a GPL program for trillions of dollars, theoretically, as long as you, if someone does purchase your thing, provide the code.

 

What is more commonly done, however, is providing prebuilt packages/binaries for a (voluntary) fee. Krita, for example has done quite well with that.

 

[CacoG0ld3n]

Yes, On Steam they sell a port or I think the game, it's called ProBoon Lite but it has different maps :0 

 

(P.D I was wrong, they don't sell it yet, they haven't even published it. :( sorry)

[The Doommer]

On 10/20/2023 at 9:33 PM, ax34 said:

you can't add DRM to it.

Petition to make all video games with the GZDoom engine

 

Jokes aside, DRM does decrease performance so