Previously I was a licensee of Unreal 3. With that engine I was legally obliged to put a “powered by Unreal” logo during my splash screens at the start of the app.
Does UE4 have a similar rule? I’ve read the EULA and various branding PDFs and am none the wiser.
Per Section 11 of the EULA, you are required to credit UE4 in the credits of your game, but that’s all. In fact, just under the EULA, licensees don’t have a trademark license to use the Epic trademarks further, including on a splash screen. For licensees that are interested in further use of the trademarks, there is a separate trademark license they can sign (which can be found here).