Why do you need to redistribute them if your goal is merely to solve your own problem? (That's the specific context of the quote in the parent comment.)

>Why do you need to redistribute them if your goal is merely to solve your own problem?

Because "you" in this case is typically a game studio. "Solving your own problem" means shipping your game.

Do you think it would make any sense for epic to forbid studios from shipping games that contain a modified engine?

Huh. I have no idea what point you're trying to make.

Virtually everyone modifies Unreal C++ code. Some indie projects are blueprint only. But modifying the engine C++ source code is practically an expectation.

Can those source code modifications be easily shared with other developers? Well they can't be publicly dumped on GitHub. Can they be shipped to consume in a compiled binary? Absolutely.

Gotcha!

> Yes, but can you redistribute those modifications? Under what terms?

They have a marketplace for selling or sharing stuff like that. If it's a huge chunk of code that's mostly original Unreal code, there are probably some license issues (I have no idea) with just sticking it in your github, but I actually have seen stuff like that on github, so, maybe not.

Yes you can redistribute modified versions of the engine to other parties. Public offerings need to be done through an epic marketplace but that can be for free. The modified engine is still beholden to the original license terms.

As I understand it the sanctioned way of sharing code added to UE is to fork it on github and publish changes to your fork.

Being a fork it will only be available to other people in the Epic Games github org which is only people who have agreed to Epic's licensing terms, and your modified engine remains under that same license.