This could be one of the reasons why the Nemesis system hasn’t been seen in many games: Warner filed it back in 2015.
Mark Brown’s newest Game Maker’s Toolkit video discusses the Nemesis system that was used in Middle-Earth: Shadow of Mordor and its sequel, Middle-Earth: Shadow of War. It’s a system that personalizes orc NPCs in response to actions players take against them. Warner Bros. Interactive has filed a patent for it so the system used in Monolith Productions’ titles wouldn’t be 1:1 ripped off by others.
The patent is for „Nemesis characters, nemesis forts, social vendettas and followers in computer games,” and Brown compares it to the patented floating arrow in Crazy Taxi that showed players where to go. SEGA filed a lawsuit against Fox Interactive in 2003 when their The Simpsons: Road Rage used the same mechanic. (However, the suit was settled out of court for an undisclosed amount.)
Interestingly, other games have used a system that closely resembles the Nemesis solution: Warframe, Assassin’s Creed: Odyssey, Path of Exile’s Betrayal expansion, and XCOM 2’s War of the Chosen all used a solution that followed the formula to some extent. The patent is currently pending, as it was rejected in 2019, but Warner sent it for re-examination last year. It’s now in the „notice of allowance” phase. In other words, if Warner files the necessary paperwork and pays the fees, the patent will be finalized.
We’ve seen a few interesting patents: Microsoft had a patent on games awarding bonus points „if the player performs feats of style that are not necessary tasks of the game” – it was for Project Gotham Racing’s kudos points. Bandai Namco’s patent for Katamari Damacy’s „arranging a plurality of objects” was not chased either, and several titles used it, such as The Wonderful End of the World, Anarcute, or Donut County. Electronic Arts’ patent got a green flag in late 2011 for BioWare’s dialogue wheel for Mass Effect, and even then, it didn’t stop Fallout 4 or Deus Ex: Mankind Divided from using a similar solution.
Uniloc Corporation had a patent on the concept of product activation. After it was used in an infringement suit against Microsoft, it was dubbed an act of patent trolling, then it was eliminated, as SEGA, Ubisoft, Cambium Learning Group, and Perfect World Entertainment filed a case against it. And even Nintendo is relaxed about others using solutions closely resembling something they patented. They have a patent for a sanity system after publishing Eternal Darkness, and yet, Don’t Starve, the Amnesia games, Tokyo Dark, Knock-Knock, or World of Horror used it. Namco’s infamous patent on loading-screen minigames is also interesting (for example, Ridge Racer, a PlayStation launch title, included Galaxian – completing the level unlocked eight bonus cars in the game!), and yet, The Sims 3 or Splatoon used something similar.
So despite big names filing patents, not everyone goes after you, especially if you give it a unique coat of paint.