Japan’s Patent Office has issued a preliminary rejection of Nintendo’s “monster capturing” patent application (2024-031879), a development that could bolster Palworld creator Pocketpair in the companies’ ongoing legal clash. The decision isn’t final, but it signals that the examiner views the claimed mechanic as lacking originality because similar systems existed well before Nintendo filed in December 2021.
In the office’s view, the invention could have been readily devised by someone with ordinary skill in the field. The examiner cited multiple examples of prior art across mainstream games and documentation, including a 2020 ARK: Survival Evolved video, Craftopia materials, Monster Hunter 4’s manual discussing anesthetic balls, Pokémon GO capture rates, Monster Hunter Portable 3rd, and ARK Mobile. This particular filing is also tied to two other patents Nintendo has brought into court, the parent patent JP7505852 and the child patent JP754191.
Pocketpair has been actively supplying references to earlier implementations. On April 9, 2025, the studio allegedly submitted evidence highlighting features from titles such as ARK, Tomb Raider, Titanfall 2, The Legend of Zelda, and Rune Factory 5. The company also pointed to long-standing community mods like Pixelmon for Minecraft and NukaMon for Fallout 4 to show that monster-collecting and capture-rate mechanics have been publicly known for years. Nintendo has countered that mods shouldn’t count as prior art because they depend on base games, a position critics argue is weak given the mods’ public availability and documentation.
Legally, the rejection doesn’t resolve the broader dispute in the Tokyo District Court, where Nintendo sued Pocketpair on September 19, 2024. It does, however, undercut the uniqueness Nintendo is asserting around its game design. The JPO has given Nintendo 60 days to refine its claims and present further arguments; failure to persuade could result in a final refusal, after which the company could still appeal, potentially stretching the process past 2026.
What this means right now: Nintendo’s claim to exclusive rights over core monster-capturing mechanics faces significant headwinds due to extensive prior art in popular franchises and community-driven projects. Pocketpair gains momentum in the short term, but the outcome remains fluid. Nintendo can still contest the examiner’s findings, revise the scope of its claims, and pursue appeals while the court case continues. For developers and players, the ruling underscores how entrenched and widely adopted these mechanics have become across the industry.
