Lego Juris sought registration of the shape of its brick as a Community three-dimensional mark. Mega Brands challenged the registration, arguing that the shape was dictated solely by technical function, because the studs on the surface ensure the assembly system.

The CJEU confirmed that a shape cannot be registered as a trademark if all its essential characteristics are necessary to obtain a technical result. The reason is fundamental: if the shape were protected as a trademark, competitors would be excluded indefinitely from using necessary technical solutions, an unacceptable perpetual monopoly.

The Court rejected LEGO’s argument that alternative shapes exist to achieve the same technical result. The existence of alternatives does not save the mark. What matters is whether the characteristics of the registered shape are technically motivated rather than aesthetic.

This judgment defines a clear boundary between three-dimensional trademarks and patents: technical solutions are protected by patents, for a limited term. A product shape can function as a trademark only if its essential features are arbitrary or fanciful, independently of the product’s function.