Nintendo initiated a patent lawsuit against Pocketpair, the developer of Palworld, and has intensified its focus on intellectual property enforcement. Pocketpair's defense strategy involves challenging Nintendo's patent claims by referencing prior art found in mods, which could potentially invalidate Nintendo's patent. However, Nintendo argues that mods do not qualify as prior art because they are not considered "real games." Under Japanese patent law, prior art includes inventions that are publicly known or worked prior to the patent application. Nintendo has a history of legal actions against modders, including issuing DMCA notices that resulted in the removal of content and the shutdown of multiplayer modding projects.