Nanjing dialect
In December 2010, it was announced that the film would be made, and pre-production started the same month. They began shooting on location in Nanjing, China, on January 10, 2011. The dialogue of the film was shot about 40% in English and the rest in Mandarin Chinese (particularly in the Nanjing dialect, distinct from Standard Chinese) and Japanese, with an estimated production budget of $94 million, which makes it the most expensive film in Chinese history.