Monolith Productions developed, and Warner Bros. Interactive Entertainment published, Middle-earth: Shadow of Mordor in September 2014. The game included an interesting mini-game of sorts called the Nemesis system. In it the hierarchy of orcs is in constant turmoil, whether or not the player is actively interacting with it. This interesting mechanic was then transferred to the 2017 sequel Middle-earth: Shadow of War. And now, after multiple failed attempts, Warner Bros. has managed to patent the Nemesis system. In other words no other publisher can't implement the same system in their respective games (without their permission, of course).
According to IGN, The US Patent and Trademark Office has made a decision, and this decision go into effect on February 23, and will remain as such until the end of 2035. The patent also includes Social Conquest battles from Middle-earth: Shadow of War, where players can attack each others strongholds and test the might of their own orcs.
The long-term result of all this might be, that gameplay mechanics like the Nemesis system can't now naturally evolve and get better over time, because developers always need to keep in mind that Warner bros. has the patent for it. Other developers can, of course, do their own twist on the Nemesis system, but it needs to be different enough, and can't be called as Nemesis system. Or they have to pay to Warner Bros. a fee to use a licensed version of the Nemesis system.
Already a handful of game developers have criticised the patent, like Obsidian Entertainment's Josh Sawyer, Thomas Was Alone developer Mike Bithell and Vlambeer company's Rami Ismail.