Japanese Patent Office rejects Nintendo patent linked to Palworld dispute in rare sharp tone

Japan's Patent Office has rejected a Nintendo patent application linked to the company's ongoing legal dispute with Palworld developer Pocketpair, with the decision now under review following Nintendo's appeal.

According to reports, Patent Publication No. 2026-077713 relates to a monster-catching mechanic similar to those used in the Pokémon series.

The application describes an in-game system in which players select and throw an item to capture creatures.

Automaton reported that the rejection has attracted attention from Japanese patent law professionals, with attorney Kiyoshi Kurihara describing the exchanges between Nintendo and the Patent Office as using language "rarely seen in standard patent practice."

The Patent Office reportedly cited gameplay footage from the unofficial fan game Pokémon: Generations, released around 13 years ago, as prior art when assessing whether Nintendo's proposed invention was sufficiently inventive.

The cited example described a player selecting a Poké Ball displayed on-screen, throwing it and capturing Pikachu upon a successful hit.

Following the decision, the gameplay video's comment section reportedly filled with messages from users suggesting the fan project had influenced the patent dispute.

Nintendo challenged the rejection, arguing that the Patent Office had "acted extremely inappropriately" by relying on a copyright-infringing fan game during its assessment.

The Patent Office rejected that argument, stating that "this argument has no bearing on determining inventive step," before adding that "accuracy should take precedence" if copyright concerns were to be discussed.

It also noted that avoiding references to recognisable Pokémon characters would require lengthy descriptions such as "an object in the form of a small yellow animal" instead of Pikachu or "a spherical object with a red upper half and a white lower half" instead of a Poké Ball. The Office added that "even with such rephrasing, the logical structure of the grounds for refusal remains unchanged."

Nintendo has since filed a petition challenging the rejection. The Japanese Patent Office now lists the application as having its "rejection decision under review."