After many attempts over multiple years, the Nemesis System is finally patented, and it belongs Warner Brothers Interactive Entertainment. As the system that became an instant hit in Middle-earth: Shadow of Mordor and Middle-earth: Shadow of War, Warner Brothers' patent ensures that the publisher will be able to use the Nemesis System exclusively moving forward.
The patent for the Nemesis System was initially filed as far back as 2015. However, Warner Bros. has had to file multiple times in an attempt to push the patent through. In most cases, the patent was rejected due to similarities with other patents, such as ones held by Square Enix or even Webkinz. However, WB was able to alter the language and get the Nemesis System patented this time around; it will be official on February 23, 2021.
As long as Warner Bros. maintains the necessary fees, it will be able to keep the patent until 2035. The patent makes it rather clear that the "Nemesis characters, nemesis forts, social vendettas and followers in computer games" belong to WB and Monolith Productions, the publisher and developer of the system. Many wonder what happened to the Nemesis System in gaming, as it seemed like it could have been a revolutionary idea that would be a staple in many genres. But with it now being a patent for WB, it is plausible that it becomes something that WB implements to a degree within its games moving forward.
If other developers want to use the Nemesis System, they will need to request permission from WB. It is possible to have a system that is in the same ballpark but not exactly the same as Nemesis System. But now that the Nemesis System is patented, WB would be able to take legal action if upcoming video games utilized something that it deemed was too close.
As far as the language of the patent, and what the Nemesis System actually is, the idea is that the NPCs within the game exist, interact with, and remember the actions of the player. The appearance and behavior and even hierarchy of the NPC can be affected by the player, and the NPC will remember the interactions that they had with the player. What is interesting is that the PS3 and Xbox 360 versions of Middle-earth: Shadow of Mordor did not have a very complex version of the Nemesis System, because the consoles could not handle it. However, now that the current consoles are two generations older, the Xbox Series X|S and PS5 could utilize the Nemesis System greatly, so it will be interesting to see if WB uses it.
Source: IGN