This research focuses on brand extension potential. In contrast to academic research analysing the key success factors of extensions based on consumer perceptions at a given time, this article proposes a long-term approach of brand extendibility. This process is based on three steps. This process considers the brand narratives classified in three types of contracts (delimitation, determination and mastery) and analyses their openness. Using a structural semiotic approach, we study the discourse of twelve luxury brands. Three groups of brands are identified: brands anchored in both determination and mastery contracts defined as open (with high extendibility), brands anchored in a determination contract defined as open as well as in a mastery contract defined as closed (with low extendibility), and brands anchored in a mastery contract defined as open as well as in a determination contract defined as not closed (with high extendibility but the risk of diluting the brand value). Compared with extensions actually developed by these brands, the results are discussed and managerial implications are derived.