Building Blocks of Design Law: CJEU rules on LEGO Group Modular Design Protection

Background and legal framework

The Court of Justice of the European Union (CJEU) recently issued a landmark judgment in the LEGO Group case (C-211/24) concerning the scope of EU design protection for modular systems. This recent judgment addresses fundamental questions regarding the protection and enforcement of Community designs for modular products, specifically the LEGO Group’s iconic toy building blocks and parts:

 The dispute arose when Pozitív Energiaforrás Kft. sought to import toy sets into Hungary that included building blocks and parts similar to those protected by the LEGO Group’s registered Community designs.

 

The LEGO Group initiated infringement proceedings, which led to a preliminary reference on the interpretation of Articles 8(3), 10, and 89(1) of Regulation (EC) No 6/2002 (the Community Design Regulation, “CDR”).

CJEU’s findings on the “Informed User” and overall impression

The CJEU’s judgment provides important clarification on how the CDR applies to designs featuring modular interconnection elements, the role of the “informed user”, and the interpretation of enforcement remedies. Companies operating in sectors reliant on modular or interlocking components, such as toys, furniture, and industrial products, should carefully review their design strategies considering this ruling.

Article 10 CDR establishes that a registered design protects any product that produces a “different overall impression” on the “informed user.” In assessing the scope of that protection, the degree of freedom of the designer in developing his design is to be taken into consideration. The concept of the “informed user” is pivotal: it is not defined in the regulation, but CJEU case law has consistently held that this user is neither an average consumer nor a sectoral expert, but someone particularly observant and knowledgeable about existing designs in the relevant sector.

Article 8(3) CDR provides a specific exception for modular systems. This provision is commonly referred to as the “LEGO exemption”. It allows certain design features - specifically those enabling modular systems made from mutually interchangeable parts - to be registered and protected as a Community (now EU) design, even if those features are dictated by technical function or must-fit requirements. It essentially creates a narrow carve-out from two general exclusions (Articles 8(1) and 8(2) CDR) that would otherwise deny protection to such technical features. Therefore, Article 8(3) CDR allows protection for designs enabling the multiple assembly or connection of mutually interchangeable products within a modular system - such as LEGO bricks and parts - if the design is novel and possesses individual character. The goal of Article 8(3) CDR is to protect the functional design aspects of modular systems that serve as key innovations and competitive advantages, while still preserving compatibility across product lines and manufacturers. It ensures designers can protect modular interconnection features that are both functional and distinctive, even if they look uniform or serve a purely technical role.

The informed user’s level of attention is likely to vary according to the sector concerned. The CJEU clarified that the standard for the “informed user” applies uniformly to all designs, including those covered by Article 8(3) CDR. The informed user is not a technical expert or sectoral specialist, but a person with a relatively high degree of attention and knowledge of designs in the sector. The Court rejected the notion that, in the context of modular systems, the informed user should be equated to a technical expert capable of minute technical analysis. Instead, the assessment must remain grounded in visual perception (i.e. the appearance of the product). An appropriate, relatively high level of observance or attention should be considered. It is, however, not necessary to take into consideration the perception of a user who is a specialist in the field concerned with detailed technical expertise. The Court also reaffirmed that the “overall impression” is determined by how the informed user perceives the appearance of the product, not by a technical analysis of its function. Even if the designer’s freedom is limited by technical constraints (as is common in modular systems), the assessment remains visual. However, the more restricted the designer’s freedom, the more likely it is that even minor differences in appearance may suffice to create a different overall impression and avoid infringement.

Importantly, for designs protected under Article 8(3) CDR, the features enabling modular interconnection must be considered in the overall impression assessment. This means that connection points and assembly features are relevant to design protection for modular systems, so long as they contribute to the product’s visual character.

Special reasons for enforcement exceptions

Article 89(1) CDR sets out remedies for design infringement, requiring courts to order prohibitions, seizures, and other sanctions unless “special reasons” exist not to do so. The term “special reasons” is not defined, raising questions about its scope and interpretation.

The CJEU held that “special reasons” under Article 89(1) CDR must be interpreted strictly and uniformly across the EU. Exceptions are limited to exceptional, fact-specific circumstances, such as practical impossibility for the infringer to continue the infringing acts. Notably, the mere fact that infringement involves only a small portion of a modular set does not constitute a “special reason”.

However, the court left one issue open: it did not decide whether enforcement measures, such as destruction, must also apply to the non-infringing parts of a modular set. This gap leaves some uncertainty for national courts when dealing with mixed sets that contain both lawful and infringing components.

The CJEU states that “special reasons” shall be interpreted uniformly and strictly in the EU legal order, limits the flexibility of national courts in case of infringements. The concept of “special reason” entails an exception to the court’s obligation to make the orders provided for in that provision. It therefore must be interpreted strictly and related to factual circumstances specific to a given case. Infringing components represent only a small proportion of a larger modular set, but they will not, by itself, exempt the infringer from injunctive relief. However, the CJEU missed the opportunity to decide whether non-infringing parts in the defendant’s sets are also subject to enforcement measures.

Furthermore, the link with the requirement under Article 3(2) of the Directive 2004/48/EC on the enforcement of intellectual property rights (“IP Enforcement Directive”) remains unclear. This provision states that: “[…] measures, procedures and remedies [to ensure the enforcement of the intellectual property rights] shall also be effective, proportionate and dissuasive and shall be applied in such a manner as to avoid the creation of barriers to legitimate trade and to provide for safeguards against their abuse”. While the CJEU’s strict interpretation of “special reasons” reinforces the deterrent and uniform application of remedies across the EU, it raises questions as to how national courts should reconcile this rigidity with the IP Enforcement Directive’s proportionality requirement. In particular, the obligation to ensure that remedies do not create unjustified obstacles to legitimate trade could, in certain circumstances, justify a more nuanced approach - especially in cases involving complex products or modular sets that combine infringing and non-infringing elements. The absence of clear guidance from the CJEU on how to balance the strict enforcement of design rights with the proportionality principle under Article 3(2) IP Enforcement Directive leaves open the possibility of divergent national interpretations, potentially undermining the very uniformity the Court sought to achieve.

Conclusion and practical takeaways

This judgment has significant practical implications for rights holders, manufacturers, importers, and retailers of modular products:

1. 1. 1. 1. Design protection can extend to functional connection features. The CJEU confirmed that under Article 8(3) CDR, even technical interconnection elements of modular systems (such as studs, sockets, or clips) can benefit from design protection, provided they contribute to the product’s visual appearance and meet the requirements of novelty and individual character. This clarification strengthens the position of rights holders like the LEGO Group, but it also means that competing manufacturers of compatible products must tread carefully. For instance, a company producing “compatible” toy bricks or modular shelving systems can no longer rely on the argument that connection points are purely technical and unprotectable.
            
            
         2. The “informed user” test remains focused on visual impression. The assessment of whether a design creates a different overall impression remains rooted in how an informed user perceives the product visually, not in technical analysis. Even where design freedom is limited by functional constraints, such as modular construction systems, office furniture, or mechanical components, minor visual variations in the shape, proportions, or patterning of connectors can make the difference between infringement and a lawful design. In practice, this invites companies to invest in subtle aesthetic differentiation.
            
            
         3. Following the CJEU judgment, minor infringements can have major consequences. Importing or selling modular sets that contain even a small number of infringing components can lead to injunctions and seizures. It appears that the “partial infringement” defence (i.e. arguing that only a small part of a larger set is affected) will not shield companies from enforcement action, provided these components are protected. For example, a distributor selling a large toolkit or furniture assembly set that includes a few infringing connectors will not be able to rely on the argument that the infringing elements are “incidental” of “partial”. This increases exposure for downstream actors, such as importers, retailers, and e-commerce sellers, who may not control the design of the products they sell.
            
            
         4. Enforcement exceptions are strictly limited. The CJEU held that “special reasons” under Article 89(1) CDR must be interpreted narrowly and uniformly across the EU. This approach enhances legal certainty for design owners, but it limits flexibility for national courts, as courts have little flexibility to withhold remedies.
            
            
         5. Businesses should reassess design strategies and clearance practices.
            
            For established design holders, the decision reinforces the value of design portfolios covering functional modular elements.
            
            Competitors and new entrants active in modular products should carefully review their design portfolios, carry out clearance searches before launching new products, and ensure that interchangeable parts are visually distinct from protected designs. 
            
            Importers and retailers should likewise be vigilant in monitoring supply chains to avoid the risk of enforcement actions. The judgment also highlights the importance of monitoring competitor products for potential infringement risks.

The CJEU’s judgment reinforces the harmonized approach to design protection for modular products in the EU, focusing on visual distinctiveness and strict enforcement standards. Businesses operating in sectors reliant on modular systems should review their design strategies and compliance practices to ensure robust protection and risk management.

Our team is on hand to provide further advice and support on how to navigate these challenges successfully. Engage with our design law specialists to assess the impact of this ruling on your current and future design registrations and to strategize effectively in light of these developments.