Ender's Game

In a future where humanity survives only by preemptively striking at the Formics, an insectoid alien species, the military recruits children for Battle School. Andrew "Ender" Wiggin, a prodigy of tactical intuition, is isolated from his siblings and subjected to a grueling curriculum of physical and strategic games. What appears to be a competitive training program is, in reality, a series of simulated invasions designed to forge a commander capable of leading the final, real-world defense of Earth. The narrative tracks Ender's psychological isolation and his growing realization that the stakes of his education are far higher than he was led to believe.

Description adapted from Open Library ↗.