Community-made maps?

One of the reasons for the success of many 90s/00s games was the ability for the community to make and distribute their own maps (the UT series in particular). What would be the best way to allow community map-makers for a game where maps are small and discrete, like with an arena shooter? If players downloaded the Unreal Engine would they be able to load up your game and make maps for it in the editor? Would you need to create an in-game level editor from scratch?

Thanks in advance.

Same, would be great to have some ingame editor, our have some dev kit like for ARK or squad

People have started making community-made maps for the UE4 Skateboarding game Session. They are unpacking the game, creating a level in UE4, cooking the project, and moving over the cooked files into the Session game content directories, and launching the game. To share maps, they just have to share those cooked folders, which aren’t huge.

It looks like right now if you want to make your game moddable then you need to work with Epic with making the stuff available (because you aren’t allowed to distribute components of the engine yourself)

Thanks for the responses. I thought it might be like that. I think building an ingame level editor (like Doom 2016 SnapMap) is a bit much.