The Bureau: XCOM Declassified is the second game in some kind of the franchise reboot. Despite the fact that the first game, XCOM: Enemy Unknown was a strategic game, this time is it a tactical third-person shooter. The story follows CIA Agent William Carter, who survives the attack of aliens in 1962 and becomes a member of the Bureau - secret U.S. organisation that was created to fight with threats of national security scale. However, after arriving in the bunker, Faulke - director of the facility - states that all of the U.S. military bases have been destroyed and they cannot contact the White House. With that being said, the Bureau is now re-named into XCOM and starts its story from this moment.

Despite genre difference to its predecessor, The Bureau still focuses on tactical elements of the gameplay. Agent Williams has a squad of 3 members with him included. While in the fight, the player can stop the game to give orders to his crew - change your position, use some skill or focus on the exact target.