 The show blended elements from the space opera and Western genres , depicting humanity 's future in a manner different from most contemporary science fiction programs in that there are no large space battles . Firefly takes place in a multi @-@ cultural future , primarily a fusion of Western and East Asian cultures , where there is a significant division between the rich and poor . As a result of the Sino @-@ American Alliance , Mandarin Chinese is a common second language ; it is used in advertisements , and characters in the show frequently use Chinese words as curses . According to the DVD commentary on the episode " Serenity " , this was explained as being the result of China and the United States being the two superpowers that expanded into space . 
