How did the incas build an empire in a difficult environment?

The Incas built an empire by utilizing a variety of strategies such as a centralized government, efficient communication networks (like the Inca road system), agricultural innovations (like terraced farming), and strong military organization. They also assimilated local cultures and tribes into their empire through diplomacy and strategic alliances. These factors allowed the Incas to thrive and expand their empire in a challenging Andean environment.