Mongols largely ignored the traditional Chinese examination system and relied on foreigners (typically other Mongols) to serve as officials but maintaining top-decision making posts for themselves. The Mongol law discriminated against the Chinese, treating them like slaves (according to Marco Polo). However, they were forced to make accommodations if they were to control this agrarian society. Thus, Khubulai Khan evoked the values of Confucianism by improving roads, building canals, lowering some taxes, patronizing scholars and artists, limiting the death penalty, supporting peasant agriculture, and prohibiting Mongols implanting animals on farmland. Mongol rule was still harsh, exploitative, foreign, and deeply resented.