R.U.R., drama in three acts by Karel Čapek, published in 1920 and performed in 1921. This cautionary play, for which Čapek invented the word robot (derived from the Czech word for forced labour), involves a scientist named Rossum who discovers the secret of creating humanlike machines. He establishes a factory to produce and distribute these mechanisms worldwide. Another scientist decides to make the robots more human, which he does by gradually adding such traits as the capacity to feel pain. Years later, the robots, who were created to serve humans, have come to dominate them completely.