Following Genghis Khan’s western expedition, the board game was spread to grassland areas in the 1230s before it was introduced to Europe. It was brought to the Mongolian people via Persia, thanks to the extension of the "Silk Road"(丝绸之路Sīchóu Zhī Lù) through the Mongolian grasslands. The board of the game is a square board with 64 small squares of two different color shades alternating with each other. It is pretty much the same as the board of international chess. The light-colored squares are called "white squares" and dark-colored ones "black squares". The chess pieces are also in black and white, with each color representing one of the two players. There are a total of 32 pieces, with 16 for each player, including one king, one commander-in-chief, two chariots, two elephants, two horses and eight soldiers. What’s unique about the Mongolian chess is that the elephant pieces are made into camels and soldiers are made into hunting dogs, adding some flavor of nomad life on the grassland.