Difficulty is an optional gaming scale affecting several in-game aspects in one's game. Difficulty settings are well known throughout the gaming industry, and Ace Combat features many different difficulty settings.
In respective order from easiest to most challenging, most Ace Combat games have the following difficulty settings:
- Very Easy: Suitable for first-time players.
- Easy: Suitable for inexperienced or novice players.
- Normal: Suitable for average players.
- Hard: Suitable for advanced players.
- Expert: Unlocked by beating the game on Hard. Suitable for Ace Combat specialists.
- Ace: Unlocked by beating the game on Expert. Suitable for true Ace Combat veterans.
Some Ace Combat games do not follow this pattern. For example, the portable titles only feature Easy, Normal, Hard, and Ace. Ace Combat: Assault Horizon also only features these four, but renamed Easy to Rookie, Normal to Pilot, and Hard to Elite. All of the games up to and including Ace Combat 3: Electrosphere only featured Easy, Normal, and Hard. Ace Combat 6: Fires of Liberation features a downloadable mode known as Ace of Aces, which is not to be confused for a difficulty mode as it features modified versions of part of the mission selection from the game.
Depending on which difficulty is chosen, the game will have several in-game factors altered. Difficulty affects the following:
- Damage taken: On Expert or Ace, most of the players' planes will be lucky to survive one missile hit, while on Very Easy more advanced planes can very well take ten missile hits before exploding from damage.
- Ace Combat: Assault Horizon: On all difficulties except Ace, planes automatically repair and lose their damage status. The tougher the difficulty, the slower the repairs. However, on Ace, plane damage does not repair, and the amount of damage saves at checkpoints.
- Enemy performance: On tougher difficulties, enemies will be more agile and can avoid player attacks more easily.
- Enemy plane strength: Tougher difficulties will give enemy planes a lot more strength, requiring more missiles to take them down.
- Player ammo:
- Missiles: On Very Easy, planes have far more than enough missiles to complete the mission, while tougher difficulties will require more careful use of a player's limited missiles.
- Machine Gun: On easier difficulties, planes have infinite machine gun rounds. On higher difficulties, most planes have around 400-800 bullets. (This does not apply to Assault Horizon.)