USPTO Issues Non-Final Rejection of Nintendo’s ‘Summon Character and Let It Fight’ Pokémon Patent Amid Ongoing Palworld Litigation

The United States Patent and Trademark Office (USPTO) has rejected all claims of Nintendo’s patent related to the “summon character and let it fight” gameplay mechanic, a foundational element in Pokémon games. This non-final rejection follows intense scrutiny from intellectual property lawyers who questioned the patent’s validity since its issuance.

In November, the USPTO director ordered a reexamination of the patent after public criticism highlighted concerns about the U.S. patent system granting such broad claims. Noted IP expert Florian Mueller publicly stated that Nintendo “should never” have been awarded this patent, while video game patent attorney Kirk Sigmon described the claims as “in no way allowable.”

Nintendo and The Pokémon Company are currently engaged in ongoing litigation against Pocketpair, the developer of Palworld, in Japan. The lawsuit centers on patents that Nintendo alleges Palworld infringes, with the disputed patent encapsulating the concept of summoning creatures to battle and capture them—an established mechanic not only in Pokémon but also in other franchises like Persona, Digimon, and Elden Ring.

According to reports from Games Fray, the USPTO’s rejection was grounded in “prior art” references, including published U.S. patent applications filed by Nintendo itself, as well as by Konami and Bandai Namco. This prior art undermines the novelty and non-obviousness of Nintendo’s patent claims.

It is important to note that the USPTO’s rejection is non-final, meaning Nintendo retains the option to appeal or amend its claims, potentially prolonging the examination process. The outcome of this patent reexamination could have significant implications for the ongoing Japanese lawsuit, which has been relatively quiet since October 2024.

Palworld launched on Steam priced at $30 and was simultaneously released on Xbox Game Pass for PC and Xbox in early 2024. The game broke records for sales and concurrent players, with Pocketpair’s CEO Takuro Mizobe remarking that the developer struggled to manage the unexpectedly large profits. Capitalizing on this success, Pocketpair partnered with Sony to establish Palworld Entertainment, aimed at expanding the intellectual property, and subsequently launched Palworld on PlayStation 5.

Following Palworld’s breakout success, comparisons arose between its “Pals” and Pokémon creatures, with some accusing Pocketpair of copying Pokémon designs. Rather than pursuing copyright infringement claims, Nintendo and The Pokémon Company filed a patent infringement lawsuit seeking 5 million yen (approximately $32,846) per claim plus late payment damages, alongside an injunction to block Palworld’s release.

The Japanese lawsuit involves three primary patents granted in Japan: two concerning monster capture and release mechanics, and one relating to riding characters. These patents were filed in 2024 after Palworld’s release but are divisional patents derived from Nintendo’s original 2021 filings. This suggests Nintendo’s strategic move to tailor its patent portfolio specifically to address Palworld’s alleged infringement.

In response to the lawsuit, Pocketpair has implemented gameplay changes to Palworld. A November 2024 update removed the ability to summon Pals using Pokéball-like “Pal Spheres,” and a May 2024 patch altered the game’s gliding mechanics. Pocketpair attributed these changes to pressures stemming from the ongoing litigation.

The legal battle has continued with Nintendo revising a mount-related patent mid-litigation and contesting the relevance of mods as prior art. Presiding Judge Motoyuki Nakashima, who oversees the patent division of the Tokyo District Court, remains central to the case’s progression.

Meanwhile, Pocketpair continues to develop Palworld, preparing for its 1.0 launch with ongoing updates. At the March 2025 Game Developers Conference (GDC), John “Bucky” Buckley, communications director and publishing manager for Pocketpair, discussed the challenges faced by Palworld, including accusations of using generative AI and copying Pokémon models. Buckley described Nintendo’s patent lawsuit as “a shock” and “something that no one even considered.”

The USPTO’s non-final rejection of Nintendo’s patent adds a new dimension to this multifaceted dispute, underscoring the complexities of patent law in the video game industry and the evolving strategies companies employ to protect their intellectual property.