A significant development has transpired in Nintendo’s patent infringement lawsuit against Palworld, as one of their patents is being reexamined by the US Patent Office.
For those wondering, in September 2025, Nintendo acquired a patent amid its lawsuit against Palworld. The patent in question, US Patent No. 12,403,397, relates to summoning characters and allowing them to engage in combat against one another. Now, the USPTO director has personally ordered the office to reexamine the patent.
Nintendo’s Patent Against Palworld is Being Reexamined Due to Two Prior Art References
According to a report by GamesFray, USPTO Director John A. Squires has personally ordered, at his own initiative, that the organisation reexamines Nintendo’s patent against Palworld due to two older US patent applications. US Patent No. 12,403,397’s claims 1, 13, 25, and 26 are the ones under review, and if they fall, then the other ones will fall as well, like “a house of cards.” The reexamination is being conducted due to the failure to cite prior art references in support of the issuance of this patent
The two prior art references have been specified as well. Nintendo’s ‘397 patent is related to character summons in combat, and it seems Konami and Nintendo itself have patents that can be considered prior art. Konami’s patent application was filed in 2001 and published in 2002. The other is Nintendo’s own patent application, which was filed in 2019 and published in 2020. Both of these prior art references “teach a player being allowed to perform a battle in a manual mode and in a simpler, automatic mode.”
For those wondering, reexamination doesn’t mean the patent will be revoked. Nintendo will have two months to come up with a response, and during that time, third parties can also present challenges through other prior art references. Moreover, if Nintendo tries to sue over patent ‘397 in a United States District Court, the “court would stay the proceedings pending the outcome of the reexamination.”
The director initiated the order for Ex Parte Reexamination to address the element that the original examiner believed made Nintendo’s patent distinct from the prior art. Moreover, there might not be any more developments in Nintendo’s lawsuit against Palworld in this calendar year. But, 2026 should see some decisions come into play by Presiding Judge Motoyuki Nakashima.
Regarding the lawsuit, one of Nintendo’s anti-Palworld patents was recently rejected in Japan. Additionally, the Switch 2 has surpassed 10 million units sold. What are your thoughts on Nintendo’s patent in the Palworld dispute being reexamined by the USPTO? Leave your thoughts down in the comments, and join the official Insider Gaming Discord server.
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