Command and Conquer: Generals - Zero Hour is the expansion pack for the computer game Command & Conquer: Generals, released in 2003. Zero Hour added several new abilities to each side, and a new mode of play called the Generals Challenge, where the player takes on the identity of one of nine generals (three representing each faction) and does battle against most of the other generals, eventually confronting a powerful "boss" general, General Leang.