Here's a quote from a guy on Reddit that explains why this guy is completely wrong about pretty much everything in his reply. http://www.reddit.co...da_this_was_my/
Unfortunately, you're wrong on each count. And jurisdiction is likely in the United States insofar as your infringement was "directed" at United States consumers, was done on a website subject to U.S law, and affects directly a U.S company.
(1) It is derivative works.
The fact that you consider it "re-imagining" of existing art properties does not make it non-derivative. Use, for instance, of the Pip-boy image as part of your posters is derivative, as is the fact that many are based on existing similar artwork within the games themselves. Reinterpretations are, almost by definition, derivative.
(2) It is unlikely to qualify for fair use.
Fair use is a four-factor test, consisting of (1) The purpose and character of the infringing use (including the level of transformation), (2) Nature of the copyrighted work, (3) Amount and substantiality of the copyrighted work used, (4) effect on existing traditional, reasonable, or likely to be developed markets.
In your case, the purpose and character of the use does not fall in your favor (while it is transformative, it is done without any criticism, parody, or new meaning, it is essentially a simple transformation of art elements from the games to art on your website). In a similar case, a maker of the Seinfeld Aptitude Test were successfully sued (and could not avail themselves of "fair use" protections) by the copyright owner of Seinfeld.
Your argument for non-commercial use is inapt. Commercial use does not disprove fair use, but "non-commercial" use does not prove it. Non-commercial use, especially in the context of "I do it for free" does not aid your argument, as it still competes with a traditional market for derivative works.
The nature of the work is unimportant here except insofar as it is entirely a creative work, and so deserving of complete copyright protection.
You have taken a substantial part of their art assets and concepts. And while concepts cannot be copyrighted, the particularity of these concepts would entitle them to protection.
Finally, we come to the impact on the market. There is a market for posters, and Bethesda currently licenses to other poster-makers. Your actions, while not profiting you personally, have an impact on that market. You have violated the copyrights of Bethesda, and would be unlikely to succeed on a claim of fair use.
Furthermore, as the Supreme Court found in Campbell v. Acuff-Rose Music, 510 U.S. 569 (1994), the existence of a market into which the plaintiff has not entered does not aid a fair use defense. And, as in the Second Circuit held in Castle Rock Entertainment Inc. v. Carol Publishing Group, 150 F.3d 132 (2nd Cir. 1998) a copyright holder's refusal to enter a market does not diminish their right to exclude others from it.
Your claims regarding a lack of confusion about the name (and too-cute-by-half argument that the word "fallout" cannot be protected) ignore that the analysis is a factual question, and which (in this case) you are likely to lose.
While I agree it is not in bad-faith, your argument that your domain does not cause likely confusion is factually incorrect. However, that part is irrelevant, since your bigger problem is that you did violate copyright law.