The long-running legal battle between South Korea’s gaming giants NCSoft and Kakao Games over alleged copyright infringement has now reached its most critical phase: the Supreme Court. On April 6, 2026, NCSoft’s lawsuit accusing Kakao Games’ ArcheAge War of copying core elements from Lineage 2M entered its final legal round, with the outcome poised to reshape the boundaries of intellectual property in the gaming world.
This high-stakes dispute, originally ignited in 2023, centers on whether the systems and structures that define a massively multiplayer online role-playing game (MMORPG) can be exclusively owned—or whether they belong to the public domain, free for all to use. The verdict could have far-reaching consequences not only for the two companies involved but for the entire global gaming industry, which is watching with bated breath.
NCSoft’s complaint was straightforward but forceful: the company alleged that ArcheAge War, developed by Kakao Games and its subsidiary XL Games, had copied key elements from Lineage 2M. In particular, NCSoft pointed to the character tendency system, user interface (UI) layout, and class synthesis mechanics as evidence of unauthorized imitation. The company demanded a halt to ArcheAge War’s service and sought damages amounting to 1 billion KRW (about $750,000 USD).
However, both the initial trial and the subsequent appeal in the Seoul High Court delivered stinging setbacks for NCSoft. As reported by Alpha Economy, the courts ruled that the game structure and system of Lineage 2M “belong to the public domain,” essentially meaning that many of the features NCSoft claimed as unique were, in the eyes of the law, common building blocks used throughout the gaming industry. The second trial court was explicit: “It is difficult to see Lineage 2M as having a distinct originality that differentiates it from prior games.”
Why did the courts reach this conclusion? The judges found that Lineage 2M’s systems were essentially modifications of earlier games, particularly titles like Ragnarok M and V4. These elements, the court noted, have become so widespread in the industry that they cannot be monopolized by any single company. In a pointed statement, the court explained that “the combination of various elements and rules in a game exists largely in the public domain, and the plaintiff’s game elements were merely borrowed or altered from previous games.”
For NCSoft, the stakes could hardly be higher. The company has long relied on an aggressive legal strategy to protect what it sees as the unique DNA of its flagship “Lineage-like” games. In past disputes, such as with Webzen’s R2M, NCSoft managed to win partial recognition of unfair competition claims, even when copyright infringement was denied. This time, however, the courts refused to acknowledge even unfair competition, dealing a blow to NCSoft’s efforts to defend its business model.
Industry insiders, quoted by Alpha Economy and CEO Score Daily, are closely monitoring the Supreme Court’s next move. The central legal question is whether a game’s combination of features—its structure, rules, and mechanics—should be protected as a copyrightable “expression” or simply regarded as an “idea” that anyone can use. The distinction is crucial: copyright law typically protects the specific expression of an idea, not the idea itself. But where does a game’s creative combination of elements fall on this spectrum?
NCSoft maintains that its creative choices—such as the integration of character tendency values, the layout of the UI, and the class synthesis system—represent a unique and original arrangement deserving of legal protection. An NCSoft representative told Alpha Economy, “The overall production intention and arrangement formed by the organic combination of individual elements is NCSoft’s creative individuality.”
Yet, the courts have thus far disagreed, viewing these systems as industry standards rather than original inventions. The second trial court concluded that “the system of Lineage 2M merely modifies elements from previous games and does not rise to the level of a creative work.”
Legal experts point to a pivotal precedent: the so-called “King.com” decision, in which the Supreme Court previously recognized that a creative combination of game elements can be protected by copyright if it demonstrates originality. Whether this precedent applies to Lineage 2M is now at the heart of the current case. According to the president of the Korea Game Users Association, “The biggest legal dispute in this lawsuit is whether the ‘combination of game elements and rules’ is to be regarded as a copyright-protected ‘expression’ or as an ‘idea’ anyone can use.”
NCSoft is expected to focus its Supreme Court arguments on proving that its system combinations are akin to the creative combinations recognized in the King.com case. Even if the Supreme Court upholds the lower courts’ rejection of copyright infringement, there’s another card NCSoft might play: unfair competition. The company argues that Kakao Games unfairly profited from NCSoft’s investments and achievements, even if the specific elements themselves are not protected by copyright.
However, the lower courts have so far refused to recognize such unfair competition in this case. The Supreme Court’s interpretation of what constitutes a “result of significant investment or effort” could still swing the outcome, potentially providing NCSoft with a partial victory.
The broader gaming industry is watching with intense interest. If the Supreme Court confirms that the core structures of games like Lineage 2M are public domain, the legal risks for developers of “Lineage-like” games will drop, possibly unleashing a wave of new titles in the genre. On the flip side, if the court finds even a measure of originality, it could tighten regulatory scrutiny and limit the creative freedom of rival developers.
One industry source summed up the stakes: “For NCSoft, this is a matter of defending its core revenue model. Depending on the Supreme Court’s decision, the company may have to rethink its entire strategy, and the ruling could reshape how the industry approaches similar genre games in the future.”
As the Supreme Court prepares to weigh in, the entire gaming world is holding its breath. The decision won’t just determine the fate of two companies—it will set the rules of play for an industry built on both innovation and imitation.