I think that making a mod which just makes some necessary stuff with NV and f3, is not illigal. A person still need both games, cuz, we all know that you cant edit original esm's. It's till a mod, and making mods is legal, no matter what in them. Someone started a topic about that a few weeks ago, and before it was locked, there was a rather heated argument about whether or not it's legal. The fact that it was locked should be enough for you, but l'll try to find the link Here it is: http://www.thenexusforums.com/index.php?/topic/250749-the-captial-wasteland-in-fonv/page__st__40 "Posted 23 October 2010 - 11:19 PM I'm just going to have to say that this is a bad idea. I know that you aren't intending to distribute any assets with it, but in the past Bethsoft has been rather against this sort of thing, and continuing this idea will likely lead to numerous bad things which will forever create problems both to modders and in regards to future games. This is just a bad idea which will only lead to bad things. Locking this and any other similar discussions about this kind of thing. "