After several failed attempts, WB Games has managed to successfully patent its nemesis system from Middle-earth: Shadow of War. The most recent application goes into effect later this month, solidifying the mechanic as WB Games' sole property.
An issue notice from the US Patent and Trademark Office (ta, IGN) states that from February 23, 2021, Warner Bros. will effectively own the nemesis system through to 2035. The filing itself uses very specific language – "nemesis characters, nemesis forts, social vendettas and followers in computer games" is just the start – to outline exactly what WB Games has domain over.
Essentially, the nemesis system is an algorithmic way of creating and deploying enemies for you to battle that every time they encounter you. These antagonists have personalities, and maintain themselves in a ranking system that shifts every time you fight one. It's one of the most lauded features of WB Games' recent Middle-earth open-world games that makes exploring feel worthwhile and unpredictable.
Warner Bros. has been trying to get this patent since at least 2015, failing numerous times due to bureaucratic requirements that demand specificity, or being too similar to other trademarks from companies such as Square Enix. This going through means that anyone who wants to procedurally-generate their sub-bosses in anything resembling the nemesis approach may need to talk to WB Games first.
We'll see what effect this has on entire realm into Crusader Kings 3.