Air combat (Civ5)

Introduction

Air combat occurs when an air unit enters into combat with land unit (or vice-cersa), or with another Air unit. Air combat doesn't occur until quite late in the game, during the Modern age, when the first Flight technologies are researched. Its rules differ considerably from both Land and Naval combat.

Air mechanics

The most common air units are the Airplanes. Because of the technological challenges to moving through the Air (and the amount of Fuel this takes), airplanes have very special movement rules:

Moving Airplanes

Because of fuel limitations, airplanes can't stay outside of their bases (on the open land), for extended periods of time, like all other units. That means an Airplane always has to end their turn in a base, or if they want to move to another base, they have to expend their turn to do so. In other words, Airplanes may only 'move' between bases, while what would be normal movement for other units, for them is effectively Attack range, within which they can attack an unit each turn, then return to base. Every Airplane model can 're-base' (move) to a maximum number of tiles - that means it is unable to instantly move to the other side of the world in 1 turn. More advanced Airplanes can re-base to bases further away, up to the Stealth Bomber that can literally move across continents and oceans.

Valid bases for Airplanes are:

Cities - all of your Empire's cities, including Puppet cities, but not Allied City-states. Any city may base up to 6 Airplanes, or 10 if it has an Airport.

Carriers - these big ships' main purpose is to provide bases and support for Airplanes and move them across the ocean. Normally Carriers can base 2 Airplanes, but Promotions can extend their capacity to 5 planes.

From a base, Airplanes may attack any tile within their Operative radius. This radius is larger the more advanced the unit, and may also be increased via a special promotion. Once the Airplane finishes its attack, it returns to its base (if it survives, that is).

Note that Airplanes cannot be attacked while inside their bases, and since they always finish their turns inside bases, then it follows that they can't be attacked at all. Airplanes can only be damaged via Interception, or by their targets in retaliation to their attacks.

Airplane stacking

Unlike other military units, you may stack many Airplanes in a single tile/base. Up to 6 airplanes may base within any city; an Airport's hangars add to the storage capacity, increasing that number to 10.

A Carrier can also base a limited number of Airplanes, starting at 2, and increasing via Promotions.

Helicopter units

Helicopter gunships don't follow these rules, although they're also considered Air units. Helicopters move just like Land units, with the difference that they can hover over terrain, including Mountains, ignoring all movement penalties (and bonuses) and moving 1 tile per MP. Helicopters are also able to remain outside of bases indefinitely, like other normal units. They attack according to the rules of Melee combat, but for bonus purposes are considered Air units (so, for example, units that have bonuses fighting air units are much more dangerous to Helicopters).

Atomic bomb

The Atomic bomb is also considered an Airplane unit, because it's delivered via a Bomber. It is subject to the same rules as Airplanes, including Interception.

Air combat

Air combat occurs when an Airplane conducts an attack from its base of operation. A series of events may then be triggered, according to certain rules.

Air-to-surface attacks

Any Airplane may use its Air Strike ability within its Operational range to attack a land unit or city. It will leave base, perform the attack, then return to base. Note that the attacking Airplane is prone to a retaliation attack from its target - all unit types can retaliate, including cities, just as if they were attacked in melee. However, most unit's efficiency at retaliation to Air Strikes is very low - only the specially designated anti-air units such as the Anti-aircraft gun have dangerous retaliation strength.

Airplanes may also attack Naval vessels within range, with the same results.

The best Air-to-land attack units are the Bomber-type Airplanes. Besides having a hefty Combat Strength, they can acquire a series of promotions that increase damage against all sorts of land or naval targets.

Interception

The only real defense against Air strikes is Interception. This is an automatic ability which certain units posses, and consists of a bonus attack which is triggered when a hostile Airplane enters the effective interception radius of the unit. That unit then automatically attacks the Airplane. Note that normally only 1 interception attack may be done in a turn (an extra attack may be possible after acquiring certain promotion)! Also note that Interceptions don't count towards the normal move/action of the unit in a turn, they're an extra attack.

Interception special abilities are available in all three classes of military units:

Land - Anti-Aircraft Guns and Mobile SAMs
Naval - Destroyers and Missile Cruisers
Air - Triplanes, Fighters and Jet Fighters

When there are more than one interceptors in range of the attacking Airplane, ONLY one performs an interception! This way the other interceptors may react to other Airplane attacks.

The best interceptors by far are Fighter - type airplanes. They not only can acquire promotions increasing their damage when intercepting, but also can acquire an additional Interception per turn - something none of the other units can do.

Air sweeps

Fighter airplanes have the special ability Air Sweep which is specifically designed to counter interception, so that other Aircraft could attack safely. When using the ability, the Fighter attacks a tile in such a way as to trigger a nearby interceptor's bonus attack, but evade most of its normal damage. Fighters are especially good when targeting land or naval interceptors, and suffer practically no damage during the sweep. That's not the case when they encounter another Fighter unit. What occurs then is known as 'Dogfighting' - the two attack airplanes enter in spectacular air-to-air combat. Whatever the outcome, an Air Sweep wastes 1 interception for the defending army. Promotions can improve a Fighter's ability to Air Sweep.

Surface-to-Air attacks

As mentioned above, these are only possible against Helicopters. Any Land, or Naval unit may attack a Helicopter in its range, with different success (specialist anti-air units are very dangerous when attacking Helicopters). Otherwise, Airplanes may only be attacked via Interception.

Air Recon

All Fighter units and the Stealth Bomber have a special ability - Air recon. They make automatic reconnaissance sweeps in the beginning of each turn (that don't count towards their move), which gives you permanent vision over a great range of tiles around their base. A very important ability for the late game, which allows you to better plan your offensives.

Missiles

Guided Missiles are a late-game special weapon, which is essentially another type of Air unit. Just like Airplanes, missiles may only be stationed in bases, and attack from there within their operational range. Unlike normal Airplanes, Ballistic missiles can't acquire promotions, and are usable only once - they're a one-shot, expendable weapons, and are destroyed after their first attack.

The bases possible for Missiles are a little different: besides Cities, Missiles may be stationed in Missile Cruisers (3 capacity), or in Nuclear Submarines (2 capacity).

Their Operational range is quite large, comparable more or less to a Jet Fighter's. The greatest quality of Ballistic missiles is, however, the fact that they can't be intercepted, and are essentially a sure-hit weapon.

The Nuclear Missile is also a Ballistic missile, and is governed by the above rules. It is especially terrifying that, unlike the Atomic Bomb, the Nuke can't be intercepted.