Nintendo’s Pokémon-centric monster-capturing patent gets rejected by Japan's PTO, lending unexpected strength to Palworld's legal battle

Japan’s Patent Office has turned down one of Nintendo’s patent applications, specifically number 2024-031879, for “monster capturing” implementations, which could turn the tide in Palworld developer, Pocketpair’s favor in the ongoing legal dispute between the two. However, the decision is non-final, meaning Nintendo could still object to it with further evidence.

According to a report by Gamesfray, the patent office says Nintendo’s idea lacks originality because the game mechanic already existed in older games before the company applied for it in December 2021. The new patent is closely linked to the other two patents Nintendo is using in court against Pocketpair: the parent patent JP7505852 and the child patent JP754191.

The examiner pointed out that “the claimed invention could have easily been made by persons who have common knowledge in the technical field.” The JPO also referenced prior art in older games, including a 2020 ARK: Survival Evolved YouTube video, Craftopia wiki, Monster Hunter 4 manual on anesthetic balls, Pokémon GO capture rates, Monster Hunter 3rd, and ARK Mobile.

On April 9, 2025, Pocketpair allegedly submitted evidence of these older titles to the patent office, which helped lead to the rejection, as the company had previously listed games like ARK, Tomb Raider, Titanfall 2, The Legend of Zelda, and Rune Factory 5 to argue against Nintendo’s stance.

Pocketpair had even brought up fan-made mods like Pixelmon for Minecraft and NukaMon for Fallout 4 as proof that these monster-capturing elements have been around in video games for years.

Nintendo had argued this point, stating that mods don’t count as prior art because they require base games, but many critics say it’s a weak argument, given that mods still count as publicly available ideas.

While the rejection doesn’t end the lawsuit in the Tokyo Court District, where Nintendo filed the lawsuit against Pocketpair earlier on September 19, 2024, it does, however, undermine Nintendo’s case, because it appears the patent might not be as unique as the company claims.

The odds are in Pocketpair’s favor, as Nintendo has been given a 60-day deadline to submit further arguments and change its claims, or face final refusal, with the option to appeal the decision if it is refused, which could extend beyond 2026.

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