Warner Bros. Interactive Entertainment and Monolith Productions’ Middle-earth: Shadow of Mordor (2014) and Middle-earth: Shadow of War (2017) were both notable for introducing the brilliant Nemesis system. The Nemesis system enables smarter AI for enemies, in which they can grow stronger and remember players if left alive, resulting in a unique narrative for each enemy.
However, despite being praised by critics and gamers alike, the Nemesis system was never seen applied or incorporated in any other games over the years. This is strange, considering how fast other developers often are when trying to imitate and incorporate well-received or popular game mechanics into their own games. The answer might be simpler than we expected.
According to YouTuber Game Maker’s Toolkit, Warner Bros. actually patented the Nemesis system. The patent can be found here at this website. Due to the patent, other developers are afraid that trying to implement a similar game mechanic to the Nemesis system would result in Warner Bros. taking legal action against them.
So far, only the Middle-earth games have used the Nemesis system. There’s no indication if other future Warner Bros. games could potentially incorporate the Nemesis system. If so, then the Nemesis system will stay buried for now, and there’s nothing any other game developer can do about it.