Ace Combat Zero: The Belkan War, published in Europe as Ace Combat: The Belkan War, is the eighth installment in the Ace Combat franchise and a prequel to Ace Combat 5: The Unsung War. The game was developed alongside Ace Combat 6: Fires of Liberation and released in 2006. It was the first Ace Combat game to be released under the newly-merged Namco Bandai.
The single-player campaign follows the story of a legendary mercenary ace, "Cipher", and his impact on both the outcome of the Belkan War and the lives of the enemy aces he defeated in combat. The story is narrated in retrospect by Osean journalist Brett Thompson and a series of his interviews with Belkan War veterans, in particular with Cipher's former wingman Larry "Pixy" Foulke.
Cipher (callsign "Galm One"; real name unknown) is the player character of the game and the flight lead of the 66th Air Force Unit. His real identity and name are never revealed, but he eventually distinguishes himself as "The Demon Lord of the Round Table" by defeating a large number of Belkan aces over the Airspace B7R. Although the player is free to choose any plane for Cipher, he canonically flies an F-15C Eagle.
Larry "Pixy" Foulke (callsign "Galm Two"; also known as "Solo Wing") is the player's original wingman, introduced in the first mission. His nickname "Solo Wing" refers to an incident before the events of the game when he lost the right wing of his Eagle in combat, but still managed to land it safely. To commemorate this event, Pixy sports a unique paint scheme with his right wing painted bright red. This story may have been based on an real life training incident with an Israeli F-15D Eagle in 1983. Pixy goes missing in action in mission 12 but returns in the final one. Before his disappearance, he pilots an F-15C Eagle like Cipher.
Patrick James "PJ" Beckett (callsign "Crow Three", later "Galm Two") is first introduced as a member of the supporting Crow Squadron in mission 09. However, when Pixy goes MIA, PJ replaces him as Cipher's wingman, flying with him until the final mission. Throughout the game, he flies an F-16C Fighting Falcon.
The Belkan War features more named enemy units (most of them members of the legendary Belkan Air Force) than all prior Ace Combat games to date combined; consequently, dogfights against small squadrons of highly skilled AI pilots play a much larger role in this game than in others. It is also the only installment to feature the Ace Style system, which determines the course of the story according to the player's conduct on the battlefield.