For those of us who have been around for a while will remember the days of using UnrealEd for Unreal/UT/UT2004 and creating maps, mods and the like for the game.
Now, it seems, we have come full circle with the arrival of UEFN (Unreal Editor for Fortnite) a PC application for people to create content for Fortnite alongside the other tools already there.
Over time, UEFN will evolve to feature most of the same tools available in Unreal Engine. Today in the public beta, UEFN enables a wide variety of games and experiences ranging from highly stylized cel-shaded team combat to ultra-realistic sims, playable right inside the Fortnite you already have installed.
If you've never had the experience creating with Unreal Engine and what an idea of how to get started with UEFN Epic have put together a set of resources to do just that. Check out the Getting Started guides.