Introduction
Games Workshop is in the same position today as the music industry was at the time of Napster. In principle they have a strong legal monopoly on their IP and copyrights which their lawyers enforce way more strongly than is the norm in the gaming world. Consider how many of the common tropes of sci-fi and fantasy games, and off-handed references between one game and another, that would never have happened if every producer enforced their IP as strongly as GW.

Furthermore, after the arrival of rivals like Mantic and Avatars of War, many of GW’s ideas have effectively been diluted to the point where their presence in the market allows third-party publishers and producers to release ideas and miniatures that are similar in background and aesthetic to GW’s. (Orange-haired berserker dwarves are no longer the sole monopoly of GW. Nor are evil elves with lizard capes and crossbows.)

Around the time of Napster, individual people were deterred and fined astronomical amounts for distributing music that they did not have the rights to. But through force of numbers, unlicensed distribution won out over IP, and today we can listen to every song on YouTube. I believe that we are today in the same position regarding the status of GW’s copyright and IP. The ideas have effectively been diluted and seeped into the public domain, but for the IP to be free, the movement needs people who are willing to risk their necks, and understandably, not many people are willing to do so.

Most notably, people could push the boundaries of GW’s alleged IP and copyright by publishing products and works which are allowed within the confines of copyright law but which GW wants you to believe are illegal (more on this below).

Getting sued for copyright infringement is scary, and most small-time producers cannot afford the cost. There will be victims in the fight to release fantasy and sci-fi works that are in some sense inspired by GW. But the reality of copyright and IP laws (and even patent laws, as Elon Musk will attest) is that they are not enforceable if the opposition is determined enough. GW wants to keep you scared. But the reality is that GW only needs to lose once to lose for good. Just like the music industry only needed to lose once to lose for good.

Here are some observations on copyright and IP law that I have gathered.

“Fair Use” and Criticism in the U.S.
Under U.S. law, it is almost impossible to restrict the criticism of a publication. This means that if you are a U.S. citizen, publishing in the U.S., you can actually post entire statlines and points costs of units online, as long as your purpose for doing so is criticism. For example, you could write a post on your personal blog called “Review of Warhammer Armies: Wood Elves 8th edition,” which pretty meticulously ran through all of the units as long as your post was clearly intended as a criticism of that publication.

Games Workshop wants you to believe that they can prevent you from posting such information, even if you phrase it as criticism. To maintain this illusion, they send threatening Cease and Desist letters to writers who publish such information, but U.S. law is fairly clear about the right to fair use for the purposes of original commentary and criticism.

Game Rules Are Not Copyrightable
In the U.S. at least, game rules are not copyrightable unless they are the subject of a patent. This means that in principle there is nothing copyrightable about a statline and a points cost (although unit names can be trademarked and *are* trademarked by Games Workshop, which places certain restrictions on the use of their names).

This means that in principle there is nothing to stop you from publishing the rules for entire armybooks as long as you (1) omit all background text, (2) rename the units that are the subject of GW’s trademarks, and (3) rephrase the specific way in which the rules are phrased.

Games Workshop tries to maintain their grip on the rules by interspersing the rules with background and fluff. Remove the background and fluff, and you remove the copyright.

Products That Are “For Use With” Have Been Ruled Legal
Producers have previously released products that have no use on their own, but are solely “for use with” another party’s products. For example, a company that did not own the rights to the board game Trivial Pursuit has released a module that had no use on its own, but was made “for use with” Trivial Pursuit. The case was taken to court, and the producer’s right to release a product that was meant “for use with” another producer’s product was upheld. Similarly, a recent court ruling in the EU upheld a third-party producer’s right to produce coffee capsules for Nestle’s Nespresso machines, even though these machines are the subject of a patent from Nestle and therefore entitled to increased protection.

In principle, this means that people should be able to release their own “for use with” modules for Warhammer. For example, a “Warhammer Armies: Fishmen” should be your prerogative to release to market as long as you omit all background text that infringes on GW’s specific trademarked units (i.e. don’t mention Skaven in the fluff). Like the capsules that were released “for use with” the Nespresso machine, you should in principle be able to release your own Fishmen models “for use with” Warhammer proper.

Disclaimer
These observations should be seen as my personal reflections on Games Workshop’s IP and copyright. This post should not be construed as providing legal advice of any kind. Though reasonable arguments and extrapolations can be posited from previous court rulings, there is no “hard formula” for determining the limits of copyright and IP in advance, before they have actually been tried in court.