Nintendo’s Patent Defeat: Why the US Patent Office Revoked the ‘Summon Character’ Mechanic

The way Nintendo’s most contentious patent was revoked is especially ironic. It was not necessary for the US Patent and Trademark Office to launch a single video game. When the patent was first granted in September of last year, critics immediately pointed to twelve games, including Persona, Palworld, Pokémon, and others, but no one sat down with a controller and played through them. The examiner was not required to. Because Nintendo’s claim appeared less like a novel invention and more like a description of things the industry had already figured out, sometimes more than twenty years ago, when four documents that were sitting right there in the prior art record—in the quiet archives of previously filed patents—were stacked together.

The patent itself, which was formally submitted by Nintendo in March 2023 and approved by the USPTO in September 2025, addressed a particular gameplay mechanism in which the player calls forth a sub-character to fight on their behalf, with the choice to either give it direct manual control or allow it to function automatically. A Pokémon battle is the most obvious real-world example. Your creature appears after you toss a Poké Ball, and you can either give it commands or observe its actions. This was described as a novel, protectable invention in Nintendo’s ‘397 patent. The gaming community and legal observers reacted with a mix of shock and annoyance when it was approved. Kirk Sigmon, a video game intellectual property attorney, stated clearly: “I strongly disagree with this result.” These claims, in my opinion, were completely unacceptable.

What came next was out of the ordinary. Without a formal request from any other company, USPTO director John A. Squires personally ordered a re-examination of the patent in November 2025. The final section is important. Only 175 of the approximately 15,000 ex parte reexamination requests submitted since 1981 have ever been approved at the director’s request. This was the first personal intervention by a USPTO director since 2012. The silent machinery of reexamination began to turn when Squires raised “substantial new questions of patentability” based on earlier patents.

All 26 of the patent’s claims were rejected in the ruling, which was released in early April 2026. The logic is a little embarrassing for Nintendo and almost elegant in a legalistic manner. Nintendo owns two of the four prior art references that the examiner cited. Sub-characters fighting alongside a player is described in the 2020 Nintendo patent Taura. Another Nintendo filing from 2022 that addresses similar topics is Motokura. Eighteen of Nintendo’s twenty-six patent claims fall apart when those two are combined with Yabe, a Konami patent from 2002 that deals with automatically or manually controlled sub-character combat. The examiner referred to Bandai Namco’s 2020 Shimomoto patent as the “missing link” that eliminates the remaining eight. In summary, Konami’s two-decade-old filing and Nintendo’s own earlier work rendered the new patent legally unsupportable. The company’s institutional memory contributed to its downfall.

It’s difficult to ignore how much of this legal drama has been occurring concurrently with Nintendo’s ongoing lawsuit against Pocketpair, the Japanese studio that created Palworld, an open-world monster-catching game that debuted in early access in January 2024 and quickly attracted millions of players due to allegations that it overused the design language of Pokémon. In September 2024, Pocketpair was sued by Nintendo and The Pokémon Company in Tokyo District Court for allegedly violating several patent rights. Although the particular patents at issue in that Japanese lawsuit are distinct from the ‘397 patent that was denied in the US and concentrate on animal mounts and creature capture mechanics, it is hard to ignore the larger picture. The USPTO’s rejection represents a significant breach in the legal framework that Nintendo has been carefully constructing around fundamental game mechanics.

Pocketpair hasn’t acted as a passive defendant. In response to the lawsuit, the studio has already altered Palworld, patching the glide mechanic in May of last year and eliminating the ability to summon Pals by tossing Pal Spheres in November 2024. Like a business attempting to keep development going while a legal ceiling gradually drops, each change arrives subtly in an update without any announcement. Nintendo’s capture-and-release patent application was already denied by the Japan Patent Office in October 2025. That is the pattern of the US rejection.

It is worthwhile to cling to the USPTO ruling’s non-final status. Nintendo can file an appeal with the Federal Circuit if it doesn’t agree and has two months to respond, with the option to extend. The business may still use the twenty-six claims in court, albeit with a much narrower scope, if even one of them survives. Legal observers predict that Nintendo will contest the examiner’s presumption that a developer would inevitably integrate concepts from different patents as well as the interpretation of the prior art. This is a plausible argument, but it will be difficult given the specificity of the rejections.

The deeper question of what game mechanics can and should be owned is what this case keeps returning to. For many years, the term “summoning a companion character to fight” has been used in video games, either automatically or manually. It appears in Digimon, Shin Megami Tensei, the spirit ashes of Elden Ring, and numerous independent games centered around fighting and collecting creatures. Most observers believe that it is incorrect for any one company to build a fence around that mechanic and charge rent, which is likely why the initial response to the patent’s approval was so overwhelmingly negative. It appears that the USPTO ultimately agreed. The question now looming over Kyoto is whether Nintendo will accept that conclusion or fight its way to a more limited version of the claim.