Japan's Patent Office Rejects Nintendo Monster-Capture Patent in Nintendo Palworld Lawsuit Setback

Japan's Patent Office has upheld its rejection of a Nintendo patent application for an "in-game monster-capturing system" closely tied to the ongoing Nintendo Palworld lawsuit against developer Pocketpair. The rejection cites a 2013 YouTube video of an indie fan game called Pokemon: Generations as prior art, arguing Nintendo's proposed mechanics lacked sufficient inventive step. The decision has drawn attention not only for its legal implications but also for unusually sharp language from the patent examiner responding to Nintendo's counterarguments.

The Patent Rejection and Prior Art Evidence

The Japanese Patent Office published notice of rejection for divisional patent application No. 2026-019762 last week, which describes mechanics for capturing in-game monsters. The examiner cited specific gameplay footage from Pokemon: Generations, a prototype 3D fan-made game uploaded by YouTuber JolteonPlays in May 2013, demonstrating that the core mechanics Nintendo sought to patent—such as selecting and throwing a Poké Ball to capture creatures—already existed in publicly available form over a decade prior.

Under international patent standards, an invention must demonstrate an "inventive step," meaning it would not be obvious to someone skilled in the field compared to existing prior art. The patent office determined that Nintendo's application failed this threshold based on the 2013 gameplay demonstration and other existing evidence.

Nintendo's Copyright Argument and the Examiner's Response

Nintendo's legal team disputed the rejection by arguing that the Pokemon: Generations video represented an infringing product that violated copyright and trademark protections. The company contended the examiner "acted extremely inappropriately" by treating an unauthorized fan game as legitimate prior art. However, the patent office clarified in its final decision that copyright infringement status has no bearing on whether an invention demonstrates sufficient inventive step under patent law—these are separate legal considerations.

The examiner's written response contained language remarkable for patent proceedings. Japanese patent professionals noted that both Nintendo's objections and the examiner's replies included statements "rarely seen in standard patent practice," with Japanese users even sharing their favorite quotes from the legal exchange on social media.

Broader Implications for the Nintendo Palworld Dispute

This patent rejection does not directly conclude the Nintendo Palworld lawsuit, as the rejected patent is only indirectly related to the broader legal family of claims involved. However, it represents a significant moment in the dispute, which has already seen Pocketpair make design adjustments to reduce similarity with established Pokemon mechanics. Industry observers note that some commenters may overestimate the immediate impact of this single patent rejection on the overall case.

The decision has resonated with gaming communities celebrating the outcome as a victory for creative freedom. Comments on the original Pokemon: Generations video, which now appears in official patent office documentation, express appreciation that fundamental game mechanics cannot be monopolized through patents when prior art demonstrates their existence.