XCOM is a popular video game series that combines strategy and tactical combat. Players take on the role of a commander leading a team of soldiers to defend Earth from alien invasions. The game features turn-based battles where players must carefully plan their moves, using different classes of soldiers, each with unique abilities, to outsmart and defeat alien foes. In addition to combat, XCOM involves managing resources and making critical decisions that affect the overall war effort. Players must research new technologies, build facilities, and maintain morale among their troops, all while facing the ever-growing threat of extraterrestrial enemies.