Japan Patent Office Flags Nintendo Patent as Not Inventive — What It Means for Palworld
- Sagar Mankar
- 1 day ago
- 3 min read
Nintendo’s ongoing legal battle against Palworld developer Pocketpair has taken an unexpected turn after the Japan Patent Office (JPO) rejected one of the company’s key “monster capture” patent applications. The decision, while non-final, casts doubt on the originality of gameplay mechanics at the heart of Nintendo’s lawsuit and could influence the broader dispute over creature-catching mechanics in video games.
What exactly did the Japan Patent Office reject?
According to reports from Games Fray, the JPO issued an “office action” rejecting Nintendo’s patent application 2024-031879, part of the company’s wider family of patents covering monster capture and summoning mechanics.
The office determined that the claimed invention “lacked an inventive step” following a third-party submission of prior art.
In other words, the JPO found that Nintendo’s patent didn’t introduce anything sufficiently new compared to existing games that featured similar mechanics. The cited examples include Studio Wildcard’s ARK: Survival Evolved, Capcom’s Monster Hunter 4, Pocketpair’s Craftopia, browser game Kantai Collection, and even Niantic’s Pokémon GO, ironically, a game associated with Nintendo itself.
Why this patent matters in the Palworld lawsuit
This isn’t just any patent rejection; it directly relates to Nintendo’s ongoing lawsuit against Pocketpair, filed in September 2024, where the company accused the developer of infringing “multiple patent rights” related to Pokémon-style creature capture mechanics.
The rejected 2024-031879 application is a “sibling” and “parent” filing connected to two other granted patents (JP7493117 and JP7545191) currently being used in court. This means it sits in the middle of the same patent family Nintendo is relying on in its case. If one link in that chain is considered invalid, it could raise doubts about the legitimacy of the others.
As Games Fray explains, this “sibling-parent” structure makes the rejection potentially significant. If the JPO believes one patent in the family lacks originality, the reasoning could easily extend to the patents Nintendo is actively asserting against Pocketpair in Tokyo District Court.
Pocketpair’s fingerprints on the prior art submission
Although the JPO didn’t disclose who submitted the prior art, the timing strongly suggests Pocketpair may have been involved. The developer’s legal team filed similar evidence in April 2025, citing a range of games from ARK and Tomb Raider to Zelda, Titanfall 2, and Rune Factory 5, all of which demonstrate preexisting gameplay systems resembling Nintendo’s claims.
Pocketpair even cited community mods, such as Pixelmon for Minecraft and NukaMon for Fallout 4, arguing that fan-made content also contributes to what’s publicly known and therefore counts as prior art.
Nintendo then argued mods shouldn’t count as prior art, a stance that drew criticism for narrowing what qualifies as “publicly known” ideas.
What happens next for Nintendo?
Nintendo has 60 days from the JPO’s October 22 notice to respond. The company can either modify its patent claims or argue against the examiner’s conclusions. If those efforts fail, Nintendo may appeal the decision, potentially extending the process into 2026.
Meanwhile, the Tokyo District Court lawsuit continues, but this development undeniably complicates Nintendo’s position. A JPO rejection doesn’t automatically determine the outcome of a court case, yet judges often respect findings from patent examiners, particularly when they question the novelty of a core gameplay idea.