Battlefield 4 has no plans to include mod support, DICE has confirmed. Though unsurprising since Battlefield 3 was similarly un-moddable, DICE general manager Karl-Magnus Troedsson did acknowledge the demand and mention that they are thinking of how to implement user-generated content in the franchise.
"We also would like to see more player-created content, but we would never do something like this if we feel we couldn't do this 100 percent," Troedsson told PC Gamer. "That means we need to have the right tools available, we need to have the right security around this regarding what parts of the engine we let loose, so to say. So for BF4 we don’t have any planned mod support, I have to be blunt about saying that. We don't."
However, this cloud has a slight silver lining. "But it is something that we are thinking about for the future, where we are going with the product, et cetera. So user-created content is something that’s very interesting to us, but I’m sorry to say that we will not have mod support in BF4."
Pressed to explain the "future" remark, Troedsson talked about the franchise as a whole, so it sounds like any possibility of UGC would be in some future Battlefield game. He says they have been discussing that "quite a bit."