Nintendo Sues Palworld Maker Over Game Mechanics — Patents Rejected

Nintendo Co., Ltd. and The Pokémon Company filed a patent infringement lawsuit against Pocketpair, Inc. in the Tokyo District Court on September 18, 2024, targeting the mechanics of Palworld, the monster-catching survival game that sold 8 million copies in its first six days and reached 25 million players within a month of its January 2024 launch. The lawsuit targets three Japanese patents covering creature-capture and mount-switching gameplay mechanics. Nintendo seeks an injunction against Palworld’s distribution in Japan and compensation for a portion of damages incurred between the date of patent registration and the filing of the suit.

As of May 2026, the case in Tokyo District Court has not reached trial and no verdict has been issued. Nintendo’s patent strategy has faced significant damage on two fronts: the Japan Patent Office rejected a key Nintendo patent application in October 2025, and the U.S. Patent and Trademark Office issued a non-final rejection of all 26 claims in a core Nintendo summoning patent in April 2026. The lawsuit is the highest-profile patent litigation in video game industry history, and its outcome could reshape how game mechanics are protected as intellectual property globally.

Nintendo vs. Pocketpair Palworld Lawsuit Timeline and Updates

January 2024 — Palworld Launches to Record-Breaking Numbers

Pocketpair released Palworld on January 19, 2024, on PC via Steam and Xbox consoles. The game reached 8 million copies sold within six days and 25 million players within a month. It was immediately described by observers as “Pokémon with guns,” referencing the visual similarity between Palworld’s creatures and Nintendo’s Pokémon franchise. Palworld’s commercial success made it an instant target for scrutiny. That same month, IP commentary began questioning whether Nintendo would take legal action.

September 18, 2024 — Nintendo and The Pokémon Company File Suit

Nintendo and The Pokémon Company filed a patent infringement lawsuit against Pocketpair in the Tokyo District Court on September 18, 2024. Nintendo’s official statement confirmed the lawsuit “seeks an injunction against infringement and compensation for damages on the grounds that Palworld infringes multiple patent rights.” Nintendo emphasized it would “continue to take necessary actions against any infringement of its intellectual property rights.”

Critically, the lawsuit is a patent case, not a copyright or trademark case. Nintendo did not allege that Palworld’s creatures were copied designs. The legal theory focused on game mechanics: specifically the act of throwing sphere-shaped objects to capture creatures, creature-combat systems, and mount-riding mechanics. Nintendo had applied for divisional patents from late 2023 onward that observers noted were optimized for the purpose of targeting Palworld specifically, with priority dates predating the game’s release.

Pocketpair responded publicly, stating the company was “surprised” by the suit and intended to vigorously contest both the infringement claims and the validity of the patents themselves.

November–December 2024 — Pocketpair Alters Summoning Mechanics

In patch v0.3.11, released in November 2024, Pocketpair removed the ability to summon Pals by throwing Pal Spheres, replacing it with a static summon that places the Pal next to the player. Pocketpair confirmed this change was a direct result of the Nintendo litigation. The studio expressed disappointment with the alteration but stated that the change was necessary because the alternative would have “led to an even greater deterioration of the gameplay experience” — a reference to the risk of an injunction forcing broader changes or restricting distribution.

February 2025 — Nintendo Obtains US Patent, Signals International Expansion

On February 11, 2025, the USPTO granted Nintendo US patent No. 12220638B2, covering a gameplay system for capturing creatures in a virtual environment. The grant signaled that Nintendo was positioning its patent portfolio for potential US litigation, though no US lawsuit has been filed as of May 2026. Nintendo’s US patent applications are sister applications to the Japanese patents being asserted in Tokyo, covering similar game mechanics under US patent law.

April 18, 2025 — Games Fray Accesses Tokyo District Court Case File

Specialist gaming IP publication Games Fray sent a Japanese lawyer to the Tokyo District Court to access the case file of the Nintendo vs. Pocketpair litigation. The resulting reporting provided the first detailed public analysis of the specific patent claims, Pocketpair’s defense arguments, and the procedural status of the case. Pocketpair’s defense centered on two main arguments: prior art (that the patented mechanics already existed in other games before Nintendo’s patents were filed) and patent invalidity (that the patents themselves should never have been granted).

May 2025 — Pocketpair Alters Gliding Mechanics

Patch v0.5.5, released in May 2025, changed how players glide in Palworld. Previously, players rode on Pals to glide across the world. The patch replaced Pal-assisted gliding with a generic inventory glider not tied to any specific creature. Pocketpair explicitly attributed this change to the Nintendo litigation, calling it “yet another compromise” to prevent further disruption to the game. Observers noted that Pocketpair had publicly previewed the original gliding feature, using Pals, more than six months before the priority date of Nintendo’s related patents — a fact Pocketpair cited as evidence of prior art in its defense.

September 2025 — USPTO Grants Nintendo Summoning Patent

The USPTO granted Nintendo patent US12403397, covering a system for summoning a character to fight in two battle modes, without objection in September 2025. The grant was noted by IP commentators as significant, as it appeared to strengthen Nintendo’s potential US patent position. The grant would prove short-lived in terms of unchallenged status.

October 2025 — Japan Patent Office Rejects Nintendo Application

The Japan Patent Office rejected Nintendo patent application No. 2024-031879, a member of the same patent family as two of the three patents Nintendo is asserting in the Tokyo District Court case. The JPO found the application lacked an inventive step, citing prior art from games including ARK: Survival Evolved (2015), Monster Hunter 4 (2013), Kantai Collection, Pocketpair’s own earlier title Craftopia, and Pokémon GO (2016). The rejection was significant because it directly undermined the legal foundation of closely related patents being used in the active lawsuit.

November 2025 — USPTO Director Orders Reexamination of Summoning Patent

USPTO Director John Squires, who had assumed the position in September 2025, ordered a reexamination of Nintendo’s US summoning patent No. 12403397 in November 2025. Reexamination orders by the USPTO Director are extraordinarily rare: of approximately 15,000 ex parte reexamination requests since 1981, only 175 have been granted. The director-initiated reexamination reflected institutional concern about the breadth of the patent’s claims and their relationship to existing game mechanics.

April 1, 2026 — USPTO Rejects All 26 Claims of Nintendo Summoning Patent

A USPTO patent examiner issued a non-final rejection of all 26 claims in Nintendo’s US summoning patent, No. 12403397, on or around April 1, 2026. The examiner rejected the claims as “obvious” based on prior art, citing a Konami patent filed in 2002 and a Nintendo patent filed in 2019 as references that made the claimed mechanic unoriginal. Windows Central described the ruling as “a reality check from the US Government.” The rejection is non-final: Nintendo has a two-month window to respond, which it requested an extension on, pushing the response deadline to late June 2026. Nintendo can appeal, and the patent may survive in a narrower form, but the total rejection of all 26 claims represents a severe blow to Nintendo’s US patent strategy in this dispute.

April–May 2026 — Japan Patent Office Rejects Nintendo Touchscreen Application

Nintendo filed patent application No. 2026-019762 with the Japan Patent Office, seeking touchscreen-specific coverage of monster-catching mechanics to target the upcoming Palworld Mobile game. The application is a divisional of a divisional of a divisional — three generations removed from Nintendo’s original December 2021 priority date filing, and part of the same patent family as two of the three patents being actively litigated. The JPO examiner rejected the application in April 2026, finding it lacked an inventive step, citing among other prior art Nintendo’s own publicly released Pokémon game documentation and YouTube videos from 2013 showing ball-throwing capture mechanics.

Nintendo can contest the rejection or amend the claims and resubmit, but the April 24 rejection was described by Games Fray as “a major setback” for Nintendo’s effort to obtain patent coverage ahead of Palworld Mobile’s planned 2026 launch.

What the Patents Actually Cover

Nintendo’s lawsuit does not allege that Palworld’s creatures look like Pokémon. That would be a copyright or trademark claim. The lawsuit targets game mechanics: the underlying rules and systems that govern how the game operates. Nintendo asserts three Japanese patents, which cover creature capture via thrown objects, the mechanics of having a character enter two distinct battle modes (including having a captured creature fight), and ridable character systems that allow a player to mount creatures and traverse the game world.

The breadth of these patent claims is central to the controversy. If Nintendo’s patents were upheld at maximum scope, throwing any object to capture any creature in any video game could require licensing from Nintendo. The same would apply to riding captured creatures. Critics argued this would give Nintendo effective control over a gameplay genre, not a specific creative expression. Game mechanics have historically been considered non-protectable under copyright law because of the idea-expression dichotomy: you can protect the specific artistic expression of a game but not the underlying rules. Nintendo chose patent law precisely because patents can protect functional systems — but the prior art challenges that erupted on both sides of the Pacific raised the question of whether these mechanics were actually novel enough to warrant patent protection at all.

Pocketpair’s Defense Strategy

Pocketpair’s defense arguments center on two pillars. The first is prior art: that the game mechanics Nintendo patents describe existed in commercially released games well before Nintendo’s patent filings. ARK: Survival Evolved (2015), Monster Hunter 4 (2013), Craftopia (Pocketpair’s own earlier game), and Pokémon GO (2016) have all been cited as prior art references showing that creature capture, combat summons, and mount-riding mechanics existed and were publicly known before the relevant Nintendo patent priority dates.

The second pillar is patent invalidity on the merits: that the patents were improperly granted because the claimed mechanics are not inventive, novel, or sufficiently distinct from what already existed in the field. Both the JPO’s October 2025 rejection and the USPTO’s April 2026 rejection largely vindicated this argument, finding independently that Nintendo’s claims failed the inventive step or non-obviousness requirements that patent law requires.

Pocketpair also pursued a practical workaround strategy. By proactively altering the game mechanics that most closely tracked Nintendo’s patent claims, Pocketpair reduced its exposure to injunctive relief. IP analysts at Games Fray and IPFray noted that by the time the Tokyo District Court reaches trial, Palworld may have already been sufficiently modified that an injunction would produce minimal practical effect.

What Is at Stake for the Gaming Industry

The Nintendo vs. Pocketpair case is the most significant patent lawsuit in video game history because of its potential scope. If Nintendo prevails at maximum breadth, the ruling would establish that game mechanics themselves — the functional rules of how a game operates — can be owned and exclusively licensed by a single company. Any developer building a creature-collecting, ball-throwing, or mount-riding mechanic would potentially face licensing demands from Nintendo.

The industry implications extend far beyond Palworld. Aniimo and several other creature-collection games launched or announced during the pendency of this lawsuit. A Nintendo victory would put all of them at risk. A Pocketpair victory, or a narrowing of Nintendo’s patent claims through the invalidation process, would establish that core game mechanics remain in the public domain for developers to build upon. Patent analysts have observed that Nintendo’s approach of filing divisional applications specifically tailored to the facts of a competitor’s game, after the competitor’s game was already released, represents a pattern that, if permitted, could give incumbents a tool to retrospectively threaten any successful new entry in their genre.

What This Lawsuit Teaches Consumers

The Nintendo vs. Pocketpair case is not, at its core, a consumer protection story. No one was defrauded. No one was harmed in the conventional legal sense. But it matters to anyone who plays games, because it is a fight over who owns the rules of gaming itself. The mechanics of capturing creatures by throwing objects at them existed years before Nintendo’s patents were filed. The prior art rejections from both the JPO and the USPTO say so plainly. Whether those patents were properly granted in the first place, and whether Nintendo should be able to restrict an entire gameplay genre based on them, is the question the Tokyo District Court will ultimately have to answer.

What consumers have already paid for the lawsuit is concrete and tangible: two gameplay changes to Palworld made explicitly because of legal pressure from Nintendo. The ability to throw Pal Spheres to summon creatures was removed. Gliding on Pals was replaced by a generic glider. Both changes came from a developer who said clearly that litigation forced them. Gamers who purchased Palworld in January 2024 got a game; gamers who launched the same game in late 2025 got a different one, because Nintendo’s lawyers intervened between those two dates. That is what it looks like when game mechanics become patent property: the product changes, and players absorb the cost of legal battles they had no part in.

The Nintendo vs. Pocketpair lawsuit will likely be studied in IP law classrooms for decades. Its outcome will determine whether game mechanics can be monopolized through patent law in the world’s two largest gaming markets. If prior art keeps defeating Nintendo’s applications and the Tokyo District Court narrows or invalidates the patents in suit, the decision would make it harder for incumbents to use patent filings as a weapon against new entrants in established genres. If Nintendo prevails, the calculus changes for every independent developer working in creature-collecting, crafting, or survival game spaces. The stakes do not get much higher than this. For related coverage of gaming industry lawsuits, see our reporting on the Roblox class action and the Dapper Labs NBA Top Shot settlement.