Nintendo commands one of the most aggressive IP enforcement divisions in the consumer technology industry. In September 2025, it secured US Patent No. 12,403,397 — a divisional filing constructed in 2024 to retroactively target the mechanics of Palworld — and immediately deployed it in litigation at the Tokyo District Court. Six months later, the USPTO Central Reexamination Unit rejected all 26 claims. Not because of Palworld. Because of Nintendo's own paperwork.

This episode dissects that rejection at the architectural level. USPTO Director John A. Squires personally ordered an ex parte reexamination — the first Director-initiated review since 2012 to proceed without external request — signaling institutional scrutiny that goes well beyond a standard prior art dispute. The examiner then used four prior art filings to dismantle every claim: Nintendo's own Taura patent (2019), Nintendo's own Motokura patent (2020), Konami's Yabe patent (2002), and Bandai Namco's Shimomoto patent (2020). The Taura and Motokura references alone established what Nintendo itself knew and had already disclosed. The combination was enough.

We walk through the examiner's exact logic under 35 U.S.C. § 103, map each prior art reference to the specific claims it invalidated, and analyze Nintendo's most viable defense — the hindsight bias argument — and why it is structurally compromised by the fact that two of the four references are Nintendo's own.

By the end of this episode, you will understand why broad software patents are not moats — they are mapped territory. And why your own filing history may be the most dangerous prior art your legal team has not audited.

Stars and Sand is not a law firm and does not provide legal advice. This episode is for informational purposes only. Consult qualified patent counsel before making any IP decisions.