Law and governance
The Mongol Empire was governed by a code of law devised by Genghis, called Yassa, meaning "order" or "decree". A particular canon of this code was that those of rank shared much of the same hardship as the common man. It also imposed severe penalties — e.g., the death penalty was decreed if one mounted soldier following another did not pick up something dropped from the mount in front. Penalties were also decreed for rape and to some extent for murder. Any resistance to Mongol rule was met with massive collective punishment. Cities were destroyed and their inhabitants slaughtered if they defied Mongol orders. On the whole, the tight discipline made the Mongol Empire extremely safe and well-run.
Under Yassa, chiefs and generals were selected based on their merit. The empire was governed by a non-democratic parliamentary-style central assembly, called Ikh Kurultai, in which the Mongol chiefs met with the Great Khan to discuss domestic and foreign policies. Kurultais were also convened for the selection of each new Great Khan. Throughout the empire, trade routes and an extensive postal system (yam) were created. Many merchants, messengers and travelers from China, the Middle East and Europe used the system. Genghis Khan also created a national seal, encouraged the use of a written alphabet in Mongolia, and exempted teachers, lawyers, and artists from taxes, although taxes were heavy on all other subjects of the empire.
At the same time the Mongols imported Central Asian Muslims to serve as administrators in China, the Mongols also sent Han Chinese and Khitans from China to serve as administrators over the Muslim population in Bukhara in Central Asia, using foreigners to curtail the power of the local peoples of both lands. The Mongols were very tolerant of other religions, and never persecuted people on religious grounds. This was associated with their culture and progressive thought. Some historians of the 20th century thought that it was a good military strategy, the occasion in which he was at war with Sultan Muhammad of Khwarezm, other Islamic leaders did not join the fight against Genghis — it was instead seen as a non-holy war between two individuals.