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Swimming effortlessly like a squid on your own ink and diving into it to deceive enemies—Patent No....
A Patent Attorney Explains the Nintendo/Pokémon vs. Pocket Pair “Palworld” Patent Litigation—Target Patents, Divisional Application Strategies, and Practical Aspects of Specif
0. Introduction—Note on the Context and Neutrality of This Article
The patent infringement lawsuit filed by Nintendo Co., Ltd. and The Pokémon Company against Pocket Pair Co., Ltd., the developer and distributor of “Palworld,” is currently pending before the Tokyo District Court as of July 8, 2026. No judgment, settlement, or injunction has been issued.
This article does not predict or conclude whether infringement has occurred, whether the patents are valid, or who will prevail in the lawsuit. It is an explanatory article that summarizes the case from a patent attorney’s practical perspective, based solely on publicly available information such as press releases from the parties, patent publications, and media reports.“Palworld infringes the patent” is the plaintiff’s claim, while “it does not infringe any of the patents, and the patents are invalid” is the defendant’s claim. The court’s ruling is pending, and throughout this article, we will clearly distinguish between objective facts and the parties’ claims, media reports, and analyses (accuracy is indicated using three levels: [Primary Source], [Based on Media Reports], and [Analysis]).
In this blog’s series on Nintendo’s Splatoon patents (Overview), we have explained how to read game patents—focusing on the “key points of function → claims → scope of protection”—as well as divisional application strategies.This article serves as an advanced application of that series—a practical case study based on publicly available information that illustrates how patent portfolios are used in actual litigation and how defendants respond. It is structured so that readers outside the gaming industry can also use it as a practical example of FTO (Freedom-to-Operate) analysis and divisional application strategies.
Table of Contents
- Basic Facts and Timeline of the Litigation
- Explanation of the Patents in Question—Reading by “Function” Rather Than Patent Number
- Division Applications and Registrations “Immediately Before” Filing the Lawsuit—What the Timing Reveals About Patent Practice
- Pocket Pair’s Response—A Two-Pronged Defense and Specification Changes (Preemptive Measures)
- Implications for Practitioners and Game Developers
- Summary and Future Watch Points
1. Basic Facts and Timeline of the Litigation
The basic framework is as follows: Plaintiffs = Nintendo Co., Ltd. and The Pokémon Company (jointly); Defendant = Pocket Pair Co., Ltd.; Court of Jurisdiction = Tokyo District Court. The claims seek an injunction against “Palworld” and damages (5 million yen per plaintiff, for a total of 10 million yen, plus interest on late payment.This is believed to be a partial claim for damages) [Source: Pocket Pair announcement, November 8, 2024].
Caution Regarding Misinformation: Information stating that the “claim amount is 500 million yen” has been circulating in some quarters, but this is false information that does not appear in either the primary source or major news reports. The claim amount is a total of 10 million yen plus late payment damages.Additionally, the date the lawsuit was filed was September 18, 2024; September 19 was the date of the announcement via Nintendo’s press release (please note that these dates are often confused).
| Timeline | Event | Accuracy |
|---|---|---|
| December 22, 2021 | Original filing date of the three patents in question (approximately one month before the release of *Pokémon LEGENDS Arceus*) | Primary Source |
| January 19, 2024 | Palworld Early Access Release | Primary Information |
| February–July 2024 | Three divisional applications granted through expedited examination (registration May–August 2024) | First Report |
| September 18, 2024 | Lawsuit filed with the Tokyo District Court (announced in a Nintendo press release on September 19) | Primary Source |
| November 8, 2024 | Pocket Pair Discloses Three Patents at Issue and Claims | Primary Source |
| November 30, 2024 | Patch v0.3.11 (Changes to Summoning Mechanics) | Primary Source |
| February 21, 2025 | Pocket Pair argued in a written submission that all three patents are invalid (lack of novelty and non-obviousness). They listed ARK: Survival Evolved, Craftopia, mods, and others as prior art. | Based on media reports |
| May 8, 2025 | Patch v0.5.5 released (specification change to gliding mechanism) | Firsthand Information |
| October 17, 2025 | Japan Patent Office Issues Notice of Rejection for Lack of Inventive Step Regarding Related Divisional Application (Patent Application No. 2024-031879) (Citing ARK gameplay videos, etc.) | Primary Source |
| November 2025 | Plaintiff limits claims to the old version prior to specification changes (AUTOMATON reported on June 12, 2026, confirming this via publicly available court records) | Based on media reports |
| October 1, 2026; November 9, 2026 | Technical briefing at the Tokyo District Court / Disclosure of the court’s preliminary findings (scheduled) | Based on media reports |
Situation in the U.S.—Litigation is limited to Japan
No litigation has been filed in the U.S.; the dispute is limited to Japan. In the U.S., the corresponding patent is currently in the grant and reexamination stages. In November 2025, reexamination of U.S. Patent No. 12,403,397 was initiated ex officio by the USPTO Director(It has been reported that an ex officio reexamination without third-party involvement is an unusual measure not seen since 2012), and in an Office Action dated March 25, 2026, all 26 claims received a non-final rejection on the grounds of obviousness (§103) [Based on media reports].However, since this is a non-final decision, Nintendo has the opportunity to respond. Importantly, the U.S. decision has no direct legal effect on the litigation in Japan.
Furthermore, according to media analysis, the risk of an injunction against the official Version 1.0 (reported to be scheduled for release on July 10, 2026) has effectively been eliminated due to the claim limitations made in November 2025 [Analysis: games fray, Techdirt, etc.].This is an analysis; the question of whether the older versions infringe the patent remains in dispute.
2. Explanation of the Patents in Question—Read Based on “Function,” Not Patent Numbers
The titles of all three patents in question are nearly identical, following the pattern “game program, game system….” Since they cannot be distinguished by their numbers alone, they must be interpreted based on the “functions” defined in the claims. We will examine them using the “function → claim → scope of protection” framework applied to the Splatoon series.
Patent No. 7545191—Selective Throwing for Capture and Summoning
Function: Switch between capture items (Category 1) and combat characters (Category 2); press a button to “ready,” use directional inputs to aim, and release the button to throw. If a capture item hits its target, a capture success check is performed; if successful, the item becomes the player’s property. If the target is a combat character, combat begins.
Bibliographic Information: Filed July 30, 2024; Registered August 27, 2024 (approximately three weeks before the lawsuit was filed). This is a divisional application of Patent Application 2024-031879, with the original filing date retroactive to December 22, 2021.Joint application by Nintendo and Pokémon.
Patent No. 7545191, Claim 1 (verbatim citation from J-PlatPat/Google Patents publication)
When a first category group containing multiple types of capture items for capturing field characters placed on a field within a virtual space is selected by a computer based on an operation input of pressing an operation button,the system causes the player character within the virtual space to perform a aiming action to release said capture item when a first category group containing multiple types of capture items is selected, and to perform an aiming action to release said combat character when a second category group containing multiple types of combat characters is selected, and based on directional input,the aiming direction within the virtual space is determined,based on an operation input from a control button different from the aforementioned control button, the system causes the player character to further select the capture item included in the first category group when the first category group is selected, or the combat character included in the second category group when the second category group is selected,based on an input to release the control button that was pressed while causing the player character to perform the aiming action, if a capture item is selected, causing the player character to perform an action of releasing the selected capture item toward the aiming direction,if a combat character is selected, causing the player character to perform an action of launching the selected combat character toward the aiming direction; if the capture item is launched and hits the field character, performing a capture success determination regarding whether the capture is successful or not;if the capture success check yields a positive result, set the field character struck by the capture item to be owned by the player; and if the combat character is launched to a location where it can engage in combat with the field character, initiate combat between that combat character and that field character on the field,game program.
Key Points on the Scope of Protection: This claim specifies the entire operation sequence—"switching between two categories" and "ready → aim → fire"—as constituent elements. In principle, all constituent elements must be satisfied for infringement to be established; the structure is such that the absence of even a single element may result in non-satisfaction.The basic principle of claim drafting—that adding elements narrows and strengthens the scope of the patent, while removing elements broadens it—is explained in detail in the article on Splatoon Patent No. 6543361 (subtraction of elements).
Patent No. 7493117 — Capture Probability Indicator
Function: A mechanism that displays an indicator showing the likelihood of a successful capture when aiming (as summarized in media reports and analyses). Filed February 26, 2024; granted May 22, 2024.
Patent No. 7528390 — Mount/Ride Switching
Function: A riding mechanic where the player selects a mount from their owned characters to ride, and while in the air, switches to an aerial mount via a separate input (as summarized). Filed March 5, 2024; granted July 26, 2024.
Note: The claim summaries for these two Japanese patent publications are based on media analysis; as of the time of writing this article, the original text of the publications has not been verified word-for-word.On the other hand, since Claim 1 of the corresponding U.S. patents (US 12,220,638 and US 12,409,387) has been verified word-for-word against the original text, it will be referenced below.
Column: An Overview of the U.S. Patent Family and “The Discrepancy Between Claim Language and Public Perception”
As corresponding U.S. patents, US 12,179,111 (registered December 31, 2024; dual-mode system for capture and combat),US 12,220,638 (registered February 11, 2025—success probability indicator + capture determination upon reaching proximity), and US 12,403,397 (registered September 2, 2025—summoning of sub-characters and two-mode combat.Subject to the aforementioned ex officio reexamination), and US 12,409,387 (filed September 9, 2025—mount-based) have been filed.
Reading the original text reveals a discrepancy with the public’s perception.For example, while it is often introduced as a “Poké Ball patent,” the claim language refers to a “catching item” and is not limited to ball-shaped objects (the ball shape is described at the level of embodiments). Furthermore, Claim 1 of US 12,409,387, which relates to the mount system,contains no mention of a “smooth/seamless transition”; strictly speaking, the configuration involves “the player character mounting an aerial mount character via an input separate from the mount command while the player character is in the air,” and elements of capture and ownership are also included as limitations.This is a practical example illustrating that summaries in news reports often differ from the actual claim language—the scope of protection must always be verified in the original published patent application.
A common approach to interpreting game patents is to break down the claims into a chain of “control input → processing → display”; therefore, the analysis of claim satisfaction is also conducted on a per-control-flow basis. The format explained in the Splatoon patent series can be applied directly to this interpretation.
3. Division and Registration “Immediately Before” Filing a Lawsuit—Timing Reveals Patent Practice
Let’s organize the facts.Although the original filing date for all three applications was December 22, 2021, the divisional applications actually asserted in the litigation were filed between February and July 2024—after the release of Palworld (January 19, 2024)—and were registered between May and August 2024 following accelerated examination.The registration of the final patent, No. 7545191, took place just 22 days (approximately three weeks) before the lawsuit was filed (August 27, 2024).
The legal framework that makes this possible is the combination of the retroactive effect of divisional applications (where the filing date is retroactive to the original application date) and the expedited examination system.In other words, it is legally permissible under the system to “draft new claims within the scope of the disclosure in the original application’s specification after the target product has been released, and to obtain and enforce the rights within a short period of time.” Furthermore, the “possibility that the claims were drafted after seeing Palworld” is a point raised by a third-party analyst; it is neither a fact admitted by the parties nor a finding by the court.Furthermore, keeping a divisional application pending is, in itself, a standard strategy adopted by many applicants, including major game companies.
It has been analyzed that the “pipeline strategy of keeping the parent application alive”—explained in this blog’s post on Splatoon Patent No. 5980266 (which details the divisional application strategy)—was employed in this case in the form of “drafting claims within the scope of disclosure of the original application and obtaining patent rights after the release of the target product.”(As mentioned earlier, whether the claims were drafted with Palworld in mind is speculation by third-party analysts and not a confirmed fact.)
However, this strategy is not foolproof. There are two limitations: (1) divisional claims must fall within the scope of disclosure in the original application’s specification (prohibition on adding new matter), and (2) since novelty and non-obviousness are assessed based on the retroactive filing date, the strategy remains vulnerable to prior art existing before the original application (in this case, ARK, etc., is a point of contention).In fact, the related divisional applications—Japanese Patent Application No. 2024-031879 and Japanese Patent Application No. 2026-019762—received notices of rejection on October 17, 2025, and April 24, 2026, respectively, citing grounds such as lack of inventive step(Neither of these constitutes a final decision, nor do they automatically invalidate the registered patents).
The practical lesson applies in both directions. For patent holders, “keeping division applications pending for key products builds resilience against future disputes.” For third parties, “FTO cannot be fully completed without monitoring not only the published patent gazettes but the entire patent family, including pending division applications.”
4. Pocket Pair’s Response—A Two-Pronged Defense Strategy and Specification Amendments (Preventive Measures)
Pocket Pair’s defense is reported to be based on a two-pronged strategy: (1) a claim of non-infringement and (2) a claim that the patents are invalid. In Japanese infringement litigation, under Article 104-3 of the Patent Act, a defendant may raise the defense that “this patent has grounds for invalidity” within the lawsuit itself, without having to go through an invalidity trial.According to reports [based on media coverage], in their preparatory brief filed on February 21, 2025, Pocket Pair argued a lack of novelty and non-obviousness for all three patents and listed their own titles—such as “Craftopia,” “ARK: Survival Evolved,” and the mods “Pocket Souls” and “NukaMon”—as prior art.There are also reports that a request for invalidation proceedings has been filed with the Japan Patent Office in parallel, but this information has not been confirmed. For the sake of fairness, it should be noted that Nintendo reportedly countered by arguing that “mods do not function independently and therefore do not constitute prior art” (this is not a court ruling).
Pocket Pair has explained that these changes are a precautionary measure taken while maintaining its position that “none of the patents are infringed and that they are invalid,” and does not constitute an admission that the pre-change specifications infringed on the patents.
Specification Change 1: Patch v0.3.11 (November 30, 2024)
The “throw a Pulse Sphere to summon a Pal” mechanic was removed and replaced with a system where Pals are summoned directly beside the player.Claim 1 of Patent No. 7545191 includes the element “the act of launching a selected combat character in the direction of the crosshairs” as a requirement; direct summoning without throwing raises questions regarding compliance with this “launching” requirement (the conclusion regarding sufficiency will not be discussed here).
Specification Change ②: Patch v0.5.5 (Announced May 8, 2025)
“Gliding with Pal” was changed to a glider item system. Claim 1 of the verbatim-verified corresponding U.S. patent US 12,409,387 requires “mounting a character owned by the player character.”If the Japanese patent related to riding (reported as No. 7528390) includes a similar requirement, then gliding using an item that is not a character owned by the player constitutes a change that raises questions regarding compliance with this requirement (a verbatim verification of the Japanese patent publication has not yet been completed).
A critically important practical point: Pocket Pair maintains its assertion that “it does not infringe on either patent and that both are invalid,” while explaining these changes as “preemptive measures to continue development and distribution” [Primary Source].In other words, the specification changes do not constitute an admission of infringement. This is a typical use of design-around to isolate and mitigate future risks while litigation is ongoing.
The effectiveness of this approach is evident. In November 2025, it was reported that the plaintiff limited its claims to the old version prior to the specification changes [based on media reports], effectively eliminating the risk of an injunction against the current and official versions.This can be cited as a real-world example of design-around successfully reducing the actual harm resulting from litigation (the scope of the injunction and the period covered by damages). However, the question of whether the older version infringes remains in dispute.
5. Implications for Practitioners and Game Developers
① The importance of pre-release FTO searches. Game mechanics such as user interfaces, capture, and riding can also be subject to patents. The patent portfolios of major competitors should be investigated before entering a genre or prior to release.
② Investigating “registered patents” alone is insufficient. This is the most important lesson from this case. None of the three patents at issue in this litigation existed at the time of Palworld’s release (they were granted based on divisional applications filed after release).In addition to searching published patent applications, continuous clearance is necessary—including monitoring pending parent applications and divisional families, as well as watching for applications at the published application stage.
③ The use and limitations of design-around strategies. While specification changes are effective in reducing the risk of future injunctions, claims for damages regarding past versions do not disappear (in this case as well, older versions remain subject to review).Design-around strategies must be evaluated on a per-element basis according to the claim divisions, and it is essential to be mindful of the risk of the doctrine of equivalents, under which a design may be deemed substantially identical even if the literal language is removed.
④ The defense of invalidity evidence search. Non-patent documents such as prior game play videos and mods can also constitute prior art. The fact that the Japan Patent Office cited an ARK gameplay video in its notice of grounds for rejection is symbolic. On the other hand, there remain points of contention, such as the eligibility of mods as prior art.
⑤ The rights holder’s perspective. Utilizing a pipeline of divisional applications and early examination is a legitimate strategy for obtaining patent rights. At the same time, this case demonstrates that ex post screening—such as notices of grounds for rejection issued to family applications after enforcement or (in the U.S.) reexamination at the Commissioner’s discretion—can come into play.
⑥ The reality of damages awards. The claim in this case was limited to a portion of the total 10 million yen sought, and in Japanese video game patent litigation, injunctions tend to be the primary focus. Please note that assessments such as “even if the plaintiff wins, the damages award will remain small” are based on analysts’ assessments [Analysis] and are not established facts.
6. Summary + Points to Watch Going Forward
① This lawsuit is pending before the Tokyo District Court, and no conclusions have been reached regarding infringement, patent validity, or the outcome of the case.
② This case is a valuable practical example that allows us to simultaneously observe key themes in patent practice: “divisional application strategy ×
design-around × invalidity defense.” ③ The next milestones are the technical briefing scheduled for October 1, 2026, and the court’s disclosure of its preliminary findings scheduled for November 9 of the same year [based on media reports].
We plan to update this article or publish a follow-up when there are significant developments, such as the disclosure of the court’s preliminary findings or a judgment. Please also refer to the articles in the Splatoon Patent Series: “General Overview,” “Patent No. 5980266 (Division Strategy),” and “Patent No. 6543361 (Subtraction of Claims).”
For consultations regarding FTO searches in the gaming and software sectors, pre-release clearance, or patent application and divisional application strategies, please feel free to contact us via the inquiry form on the EVORIX Intellectual Property Office website.
Main References
- Nintendo Press Release (September 19, 2024) [Primary Source]
- Pocket Pair “Report on Patent Infringement Litigation” (November 8, 2024) and Statement Regarding Patch v0.5.5 (May 8, 2025) [Primary Source]
- Google Patents: JP7545191B1 / US12179111B2 / US12220638B2 / US12403397B2 / US12409387B2 [Primary Source (Published Patent)]
- AUTOMATON (Reports on JPO Notice of Reasons for Rejection and Claim Limitations, June 12, 2026, and others) [Media Coverage]
- games fray (USPTO Ex Officio Reexamination—Non-Final Rejection of All 26 Claims) / PC Gamer / Techdirt (July 2, 2026) [News & Analysis]
Disclaimer: This article is intended to provide general information based on publicly available information (announcements by the parties, patent publications, and media reports) as of July 8, 2026, and does not constitute legal advice regarding any specific case.This case is pending litigation, and the facts and assessments may change depending on the course of future proceedings. This article does not make any determinations or predictions regarding the existence of infringement, the validity of the patent, or the outcome of the litigation.
