Point Defense

This article contains information relevant to both the C# and VB6 versions of Aurora. Where differences exist, they are noted in the appropriate sections.

Point defense is using missiles and beam weapons to automatically defend a ship, a fleet or a colony against incoming missiles, small attack craft or fighters; basically anything that comes too close for comfort.

While it is possible to attack missiles with any weapon (from fighters all the way up to a battleship's main guns), an effective point defense system usually relies on an outer 'umbrella' of anti-missile missiles, an inner 'screen' of turreted guns to catch anything that slipped through the outer barrier, plus decoys, shields, and armor to catch anything that makes it through the inner point defense.

Exact missile mechanics vary somewhat between different versions of the game - in particular, C# v2.2.0 (November 2023) had a major revision to missile mechanics that significantly changed the detailed tactics for point defense. This article will focus more on the concepts than on the detailed tactics.

Point Defense

See Ship Combat on how to set up weapons and fire controls on your ships.

See the Anti-Missile Tutorial for an introduction to defending against missiles.

Note: to understand the different modes of point defense fire, keep in mind that positions of ships and missiles are updated in five-second increments, so a missile moving at 22,000 km/s actually moves in 110,000 km "hops". That's why your sensors almost never detect objects at maximum theoretical range: they are just outside of detection range in one turn, and already some way inside it the next turn.

Anti-missile Missiles (AMM)

Generally these are small (size 1) missiles that focus on being fast and nimble. Range is a secondary concern, and the warhead only needs to do 1 damage to kill a normal missile.

See the Anti-Missile Tutorial and Missiles for details.

In the Ship Combat tab of the F4 Naval Organization window, you set their fire control to automatically engage any incoming threats within a given range with a number of one to five AM-missiles, depending on how lucky you feel. Higher numbers mean better chances to hit all threats, but you might run out of ammunition quickly.

Ship Mounted Turrets

Beam weapons with high tracking speed can effectively attack fast missiles. On all but the fastest ships, this means you will want a turret, as your ship will almost always be much slower than your best Beam Fire Control tracking speed. With small Lasers, Gauss Cannons, or Meson cannons mounted on a turret, a high tracking speed short-mid ranged weapon for Missile Interception is possible. They can also be used as short range weapons against enemy fighters or ships that dare to close in with your ships.

Ship Mounted Turrets can actually provide multiple inner layers of PD fire for the fleet by staggering weapon ranges. However, due to the high speeds of missiles and the 5-second minimum time increment, this is not always as effective in practice as it would be on paper.

Point defense modes for beam weapons

In the Ship Combat tab of the F4 Naval Organization window, you can select a fire control, assign weapons to it and set it to one of several automated Point Defense firing modes.

Area Defense

Area defense occurs during the normal weapons fire segment of a 5-second increment. If a missile crosses the engagement range of a weapon set to Area Defense during a single movement then it will not be engaged.

Use this when you want a beam weapon to fire at maximum range. For example, a combination of laser and fire control that has a range of 400,000 km might be able to fire several times at a missile salvo. Or you might split off defensive ships and order them to fly ahead of the main task group, where they can engage incoming missiles before they reach the high-value units.

Ranged Defensive Fire (C# only)

This is similar to Area Defense, except that it will only shoot at missiles whose target is also within the weapon's range.

Point Blank Defensive Fire

Point blank defense occurs at the end of the last movement segment, when the missile intercepts any ship in this task group. Range to the missile is 10,000 km, the smallest unit of distance in Aurora, thus assuring maximum hit chances at point-blank range. (In VB6, this is known as "Final Defensive Fire" instead, but the mechanics are identical.)

Point Blank Defensive Fire (self only)

Like above, but only if the missile attacks the ship carrying the fire control and not a different ship in this task group. Use this when you want to reserve this weapon to protect the high-value ship it is mounted on.

Close-In Weapon Systems

CIWS are a weapons category of their own and are designed as a ship component. They are fully autonomous, automatic gun turrets that contain their own weapons, sensors and fire controls. They always operate in "Final Defensive Fire (self only)" mode, so they do not protect other ships and cannot be used offensively. All you have to do is stick them on a ship and wait. They count as commercial components and can be mounted on any ship.

Point Defense setup within a fleet

A widely used doctrine for combat fleet defense consists of a AMM-equipped missile ship (long range), Area Defense beam-weapons ship (medium range) and a Final-Fire-laser ship (short range).

You want your PD missile launchers to be able to fire at the incoming missiles multiple times before they strike, but not waste too much ammo. Anything that gets through the missile screen gets attacked by the Area Defense ship with long range lasers. Finally, your Final-Fire ships will fire one last time at 'leakers'.

Comments

Ideally, any PD weapon would have a rate of fire of 5 seconds. Missile PD can get away with 10 or even 15 seconds, but most likely not more than that. However if you happen to know that this particular enemy fire salvoes of very fast missiles every 40 sec you may want to have some burst Final Fire capability every 30-40 sec rather than wasting short ranged turret RoF when there are no missiles in range 80% of the time.

Weapons on Point-Blank or Ranged Defensive status will always get a final shot before the missile makes its attack. Weapons on Area Defense do not.

For the C# v2.2 changes, see the changelog

• Fractional damage warheads
• Point defense changes (part 1)
• New guidance options
• Laser warheads
• Point defense changes (part 2) - Major post
• Decoy attack missiles
• Multi-warhead missiles
• AMM minimum range option
• Defensive anti-missile decoys

For an in-depth analysis of VB6 point defense, see this thread: http://aurora2.pentarch.org/index.php/topic,5197.msg53720.html#new