"Ace" is the designation given to certain enemy aircraft in the Ace Combat series. Featured in nearly all titles since Ace Combat 2 (except Ace Combat Advance), they have become somewhat of a staple for the series. Aces are named such for their target designation, which features their callsign below their aircraft's name (i.e. F-15E "Oryol".) As well, they are often characterized for their use of special paint schemes, which in most cases can be unlocked for player use by destroying them. Furthermore, they also stand out for their often superior flight capabilities, which allow them to easily evade missile fire.
In the Ace Combat series
Ace Combat 2
Main article: List of aces in Ace Combat 2
Ace Combat 2 was the game that introduced the aces concept. In total, there are 11 aces to destroy, which vary between individual pilots and squadrons. Included in this listing is the Z.O.E. Squadron, a formation of five unique aircraft present only in certain missions. During a campaign playthrough, each Z.O.E. aircraft must be destroyed in order to force the next one to spawn (i.e. if the Captain is killed in Sledgehammer, the Colonel will spawn in Power Play), eventually culminating with the ADF-01 Z.O.E. Commander in mission #21.
Ace Combat 04: Shattered Skies
Main article: List of aces in Ace Combat 04
Ace Combat 04: Shattered Skies contains a total of eighteen aces across the game's 18 missions, including an unknown ace alluded to with the F-4E Phantom II's special paint scheme named "Biela". Fitting in with the game's asteroid collision-themed backstory, all aces, excluding the new Yellow Squadron, are named after ancient astronomers; for example, Biela is named after German Baron Wilhelm von Biela, while Mrkos is named after Antonín Mrkos of Czechoslovakia.
Ace Combat 5: The Unsung War
Main article: List of aces in Ace Combat 5
Following in the footsteps of Shattered Skies, Ace Combat 5: The Unsung War contains a total of 16 ace pilots, spread through the game's 32 missions. The game is notable for introducing the trend of featuring paint schemes from previous games, in this case featuring a special Su-37 ace named "Yellow" in mission #27, alluding to the Yellow Squadron from AC04, while also featuring references to anime. It also marked the introduction of "Zipang", an F-14D ace famous for their purple, Japanese sakura-themed design.
Ace Combat Zero: The Belkan War
Main article: List of aces in Ace Combat Zero
Ace Combat Zero: The Belkan War features the highest number of ace pilots at 169, warranting its own section in the "Assault Records" menu. Each of the game's aces appears under certain circumstances, such as difficulty levels and missions, excluding those with a scripted appearance, such as the plot-related ace squadrons, Wolfgang Buchner in mission #10, and former wingman Larry Foulke, who becomes the game's final boss in mission #18.
Ace Combat X: Skies of Deception
Main article: List of Ace and Star units in Ace Combat X
Ace Combat X: Skies of Deception features over thirty ace enemies, including the new Alect Squadron. As well, the game introduces the concept of "star units", special enemy targets referred to as such due to their star-shaped radar signature, which unlock new aircraft customization parts upon destruction.
Ace Combat 6: Fires of Liberation
Main article: List of aces in Ace Combat 6
Similar to Ace Combat 04, Ace Combat 6: Fires of Liberation features fifteen ace pilots across its 15 missions, the most notable of which is Lorenz Riedel, one of the members of the Gault Squadron towards the end of the Belkan War and one of the series' few cross-game characters.
Ace Combat Xi: Skies of Incursion
Ace Combat: Joint Assault
Main article: List of aces in Ace Combat: Joint Assault
Introduced in this game is the Varcolac Squadron.
Ace Combat: Assault Horizon
Ace Combat: Assault Horizon has a different take on the "ace" concept. The main campaign features no enemy aces whatsoever, outside Andrei Markov (and, to some extent, Sergei Illich), the central antagonist. In Co-Op Mode, several new aces are introduced.
Ace Combat: Assault Horizon Legacy
As a remake of Ace Combat 2, Ace Combat: Assault Horizon Legacy features similar aces to the original game. Many of the aces, however, have different planes, and some have different names. In addition, the Z.O.E. aircraft play a role in the story and hence appear as TGT, making their destruction mandatory. Similar to Ace Combat X, shooting down these aces unlocks new parts for aircraft customization.