Czech Art Deco, Legiobank style, National style, National decorativeness, Curved Cubism, Rondocubism or Third Cubist style is a series of terms used to describe the characteristic style of architecture and applied arts, which existed mainly during the First Czechoslovak Republic. In the beginning, this particular style was completely neglected. Some rehabilitation has taken place since the 1950s. In the 1990s, attempts were made to place this specifically Czech style in the context of European Art Deco.
Rondocubism developed after the First World War in the newly formed Czechoslovakia and became the national style for a short time, but was replaced by functionalism as early as in mid-1920s. It is characterized by the introduction of round forms such as semicircles, circles and ovals, which were intended to evoke echoes of the national Slavic traditions. Rondocubism was preferred in Prague, but was also used in industrial architecture in the surrounding area. Several rondocubist buildings were built also in Slovakia, mainly in Bratislava. The main works of architectural Rondocubism are the commercial building of the Legion Bank, or Legiobanka, by Josef Gočár and the Adria Palace by Pavel Janák in Prague.
Rondocubism also manifested itself in part in painting, for example by Josef Čapek, and in object design; for example, there are some complete room furnishings, by Bohumil Waigant and Josef Gočár.