The EULA says this:
(1) for any gambling-related activities or Products; (2) for operation of nuclear facilities, aircraft navigation, aircraft communication systems or air traffic control machines, or for military use; (3) in violation of any applicable law or regulation; (4) in which the Licensed Technology is rented or leased; (5) that misappropriates any of Epic’s other products or services; (6) in support of a claim by you or any third party that the Licensed Technology infringes a patent. You also may not sell or grant a security interest in any Licensed Technology.
This seems to imply that an adults-only (pornographic) game can be made and sold with UE4.
If I were to just go by the EULA, things would appear A-OK since porn isn’t illegal, gambling, or a nuclear facility, but I was hoping for more clarification.
Perhaps I should contact the licensing team about this, but I figured I’d try posting here first since it may be a question that others have as well.