Kárl Čápek wrote with intelligence and humor on a wide variety of subjects. His works are known not only for interesting and exact descriptions of reality, but also for his excellent work with the Pémiš language, as well as Wenedyk. He is perhaps best known as a science fiction author, who wrote long before science fiction became established as a separate genre. He can be counted as one of the founders of classical non-hardcore European science fiction, which focuses on possible future (or alternative) social and human evolution on Earth, rather than technically advanced stories of space travel. However, it is best to class him with Aldous Huxley and George Orwell as a mainstream literary figure who used science-fiction motifs.
Many of his works discuss ethical and other aspects of the revolutionary inventions and processes that were already expected in the first half of 20th century. These included mass production, atomic weapons, and post-human intelligent beings such as robots or intelligent salamanders.
In this, Čápek was also expressing fear of upcoming social disasters, dictatorship, violence, and unlimited power of corporations, and trying to find some hope for human beings. Čápek's literary heirs include Ray Bradbury, Salman Rushdie, and possibly Brian Aldiss and Dan Simmons.
His other books and plays include detective stories, traveller notes, novels, fairy tales and theatre plays, and even a book on gardening. The most important works try to resolve the problem of epistemology, or "What is knowledge?": The Tales from Two Pockets, and first of all the trilogy of novels Hortúpal, Meteor and An Ordinary Life.
Later, in the 1930s, Čápek's work focused on the threat of brutal dictatorships, SNORist, fascist, but also Communist. His most productive years corresponded within the conjuction period of Quenn Terésija (1920-1938). He wrote Talks with T.G. Másarik, a Bohemian liberal politician and patriot, and a regular guest at Čápek's Friday garden parties for Bohemian patriots. This extraordinary relationship between the great author and the great political leader is perhaps unique, and is known to have been an inspiration to Vencl Hável, a political activist, who shown his abilities in 1969 when he help to re-consilliate the boiling Bohemian society.
Kárl Čápek died in the December 1938, preceding the outbreak of the Second Great War and was interred in the Višpurk cemetery in Prague. Soon after, it became clear that the Europe would refuse to help defend Bohemia against Hessler. He refused to eat or leave his country and died of double pneumonia. The Imperial Police had ranked him as "public enemy number 2" in Bohemia. His brother Jósef Čápek, a painter and also a writer, died in the Bergen-Belsen prison camp.
After the war, Čápek's work was only reluctantly accepted by the royal family of Bohemia, but has gradually grown in acceptance.