Sid Meier's Alpha Centauri/Units

Alpha Centauri features a Unit Design Workshop which is very flexible in comparison to other Civ games. For each unit, the workshop presents you with choices for each of a unit's weapon (attack strength), armor (defense strength), chassis (speed and terrain movement), reactor (hit points and build cost), and up to two special abilities (but only one until the discovery of Neural Grafting).

Unit Cost
Unit cost is calculated using the following formula:

C = W * (A + S) * 10 / (2 ^ (R + 1))

Where:
 * C is the total unit cost in Minerals;
 * W is the unit's Weapon value (Equipment for non-combat units);
 * A is the unit's Armor value;
 * S is the unit's Speed expressed in move points;
 * R is the unit's Reactor value.

It can be determined that units with a high value in all three areas (Weapon, Armor and Speed) will be much more expensive than units with a high value in just two. Therefore, it is advantageous to design your units for specific tasks rather than attempting to create all-round utility units. For example: a unit built for defending a base will need a high Armor value, but has little use for heavy Weapons or a high Speed, while for an attacker, a powerful Weapon is tantamount to effectiveness, while Armor may not be as important (the idea being that your opponent will be destroyed before they have a chance to fire back).

The basic unit cost formula is subject to several modifiers:
 * Weapon value may never be less than half the unit's Armor value
 * Final cost is halved for units with a Speed of 1
 * Armor value is halved when calculating the cost of sea units, and the final cost is halved again
 * Armor value is doubled when calculating the cost of any air unit; the final cost is quartered for combat air units
 * Add 25% to final cost for each unit of Special Ability cost
 * Add 10 Minerals if both Weapon and Armor values are greater than 1
 * Add another 10 Minerals if Weapon, Armor and Speed values are all greater than 1
 * Cmin = (R * 2 - R / 2) * 10 where Cmin is the unit's minimum final cost.

Chassis
The chassis is the most important part of the unit. It will determine where it can go (land/sea/air), how fast it goes, and what weapons or equipment it may use.

'Copter

 * Prerequisite: Mind/Machine Interface
 * Speed: 10
 * Terrain: air

The 'copter is like the needlejet, except that it can survive running out of fuel in a space without a city or airbase. Instead of being destroyed outright, it simply crash-lands, taking some damage. The 'copter can also attack as many times per turn as it has fuel remaining; however, attacking with the last unit of fuel will result in the unit crash-landing. Care must be taken when assigning go-to commands to a 'copter, as they will always end their turn upon entering a friendly base square, regardless of how many moves they have left. They are unique among non-land units in that they can blitz, or attack multiple times per turn.

Cruiser

 * Prerequisite: Doctrine: Initiative
 * Speed: 6 (8 with Maritime Control)
 * Terrain: Water

The cruiser is the ultimate transport unit. When fully upgraded, it can carry up to 16 units! In addition, it has the most movement points of any sea unit. Ideal for large maps, and long range transportation.

For warships, it may be better to buy the cheaper foil, unless of course, the distance from your base to the target is a far away.

Consider using for maritime probe team strikes, simply due to the large amounts of movement points. Do not engage in probe team warfare unless you can afford to lose the probe team. Just get to the target, do whatever sabotage you need to do, and do it quickly.

Foil

 * Prerequisite: Doctrine: Flexibility
 * Speed: 4 (6 with Maritime Control)
 * Terrain: Water

The early waterborne unit isn't as fast as a cruiser.

Gravship

 * Prerequisite: Graviton Theory
 * Speed: 8
 * Terrain: air

Late-game chassis that is strictly superior to the needlejet, equal in speed but with no fuel limitations. Very valuable chassis when equipped with high-power weapons and armor. However, unlike the 'Copter, it can only attack once per turn.

Hovertank

 * Prerequisite: Nanominiaturization
 * Speed: 3
 * Terrain: land

This is a middle-to-late-game unit that moves faster than the rover. One strategy that could be effective is building the ascent to transcendence at whatever city has the highest industry, then building these with a supply module attached to them at every other city you own and rushing them toward that city.

Infantry

 * Prerequisite: None
 * Speed: 1
 * Terrain: land

The default chassis for units. Some units (Crawlers, Formers, Colony Pods) do not display an actual infantryman in the unit graphic, instead using a custom chassis graphic sitting on enlarged treads. Infantry have a bonus to attacking cities.

Missile

 * Prerequisite: Orbital Spaceflight
 * Speed: 20 (depends on fuel)
 * Terrain: air

Middle-game chassis designed for kamikaze-style attacks. Cannot be equipped with weapons (except for special missile-only weapons) or armor and very few abilities. Can be very powerful if one uses it wisely.

Needlejet

 * Prerequisite: Doctrine: Air Power
 * Speed: 20 (depends on fuel)
 * Terrain: air

Though it can move an impressive distance, the needlejet will crash and burn if it ends a turn outside of a city or airbase. Also, the needlejet has the ability to attack twice in one turn, but if you choose to do this, it will die at the end of the second attack, as a bee dies after stinging something.

Speeder

 * Prerequisite: Doctrine: Mobility
 * Speed: 2
 * Terrain: land

This creates a rover, which, in addition to its increased speed, also applies other properties, such as the loss of the infantry unit's bonus to city invasions. Also, it counts as a mobile unit for the purposes of special armor bonuses.

Weapon
Weapons determine a unit's attack strength. Higher attack strengths give a unit better chances in battle. Missile payloads may only be equipped on the Missile chassis.

Hand Weapons

 * Strength: 1

Psi Attack

 * Prerequisite: Centauri Psi
 * Strength: uses psi combat; depends on morale or lifecycle
 * Cost: 10

Units with the Psi Attack ability attack with psi instead of weapons. The most common and basic example of such an attacker is a Mind Worm boil.

Laser

 * Prerequisite: Applied Physics
 * Strength: 2

Particle Impactor

 * Prerequisite: Nonlinear Mathematics
 * Strength: 4

Gatling Laser

 * Prerequisite: Superconductor
 * Strength: 5

Missile Launcher

 * Prerequisite: Synthetic Fossil Fuels
 * Strength: 6

Resonance Laser
Provides a 25% bonus against units with Psi Defense. The most common such defender is a native unit.
 * Prerequisite: Bioadaptive Resonance
 * Strength: 6
 * Cost: 8
 * Alien Crossfire Only

Chaos Gun

 * Prerequisite: Superstring Theory
 * Strength: 8

Fusion Laser

 * Prerequisite: Organic Superlubricant
 * Strength: 10

Tachyon Bolt

 * Prerequisite: Unified Field Theory
 * Strength: 12
 * Cost:

Resonance Bolt
Provides a 25% bonus against units with Psi Defense. The most common such defender is a native unit.
 * Prerequisite: Sentient Resonance
 * Strength: 12
 * Cost: 16
 * Alien Crossfire Only

Plasma Shard

 * Prerequisite: Advanced Spaceflight
 * Strength: 13

Quantum Laser

 * Prerequisite: Quantum Machinery
 * Strength: 16

Graviton Gun

 * Prerequisite: Applied Gravitonics
 * Strength: 20

Singularity Laser

 * Prerequisite: Controlled Singularity
 * Strength: 24

String Disruptor

 * Prerequisite: String Resonance
 * Strength: 30
 * Cost: 40
 * Alien Crossfire Only

Conventional Payload

 * Prerequisite: Orbital Spaceflight
 * Strength: 12

Fungal Payload
Fungal Missiles target a land square without a base or unit. Depending on reactor this plants an additional 1 - 4 squares of fungus, destroys most improvements and generates mindworms and a fungal tower in the detonation square. It leaves boreholes, bunkers, condensers, and solar mirrors. It destroys roads, forests, farms, soil enrichers, mines, and sensors.
 * Prerequisite: N-Space Compression
 * Strength: N/A
 * Alien Crossfire Only

Planet Buster

 * Prerequisite: Orbital Spaceflight
 * Strength: 99
 * Cost: 32

Tectonic Payload
Tectonic Missiles target a land square without a base or unit. Depending on reactor level the land will be raised 1 - 4 levels, up to the maximum of 3500m. This does not destroy improvements.
 * Prerequisite: N-Space Compression
 * Strength: N/A
 * Alien Crossfire Only

Equipment
Units with equipment cannot attack - instead they are granted a number of special actions.

Colony Module

 * Prerequisite: none
 * Equipment cost: 10

A unit with a Colony Module can build a new base. Producing a unit with a colony module consumes one population. When deployed in a base, it will add one population to that base's total population.

Probe Team

 * Prerequisite: Planetary Networks
 * Equipment cost: 4

Units with probe equipment can perform a number of covert actions.

Terraforming Unit

 * Prerequisite: Centauri Ecology
 * Equipment cost: 6

Terraforming units can create all manner of terrain improvements. The Terraforming Unit can be later enhanced with the special abilities

Terraformers are the single most important unit in the game. The AI's poor use of them contributes greatly to its poor performance. Formers are the primary way to make your cities more productive, and are the only way to make tiles more productive (except fungus, which improves with the Centauri techs). Centauri Ecology should always be one of your first techs, or a competent opponent will defeat you.

For comparison, a good unterraformed tile yields 2-1-1 (rolling and rainy, on a river), before nutrient/mineral/energy bonuses are considered. A good terraformed tile yields 0-6-6 (borehole) or 4-1-1 (condenser-farm). A fair unterraformed tile yields 1-1-0 (moist and rolling). A fair terraformed tile yields 1-2-1 (forest).

Supply Transport

 * Prerequisite: Industrial Automation
 * Equipment cost: 8

Supply units can extract one type of resource (either energy,mineral, or nutrient) from any non-cultivated square and convey it to its home base, and can also be brought to a base to apply its full production cost toward the production of a unit prototype or Secret Project.

Supply crawlers are the second most important unit in the game (second to Terraformers). Since they allow you to harvest more tiles, they act like extra population units, but without the drone problems or the nutrient requirements. In effect, supply crawlers are constructed population points, and at 30 minerals are a bargain.

Troop Transport

 * Prerequisite: Doctrine: Flexibility
 * Equipment cost: 4

A Troop Transport, as the name implies, can transport land troops from one place to the other. In combination with the Carrier Deck ability, can also transport air units. The number of transported units depends on the chassis and reactor: Foils can transport twice the reactor strength, Cruisers can transport four times the reactor strength, all other units can only transport one unit at a time.

Having a transport in a sea base along the coast allows units to freely enter and leave the base from the coast.

Defense
A unit's defense determines how well it fights when it is attacked. Defense strength affects a unit's mineral cost. Some defenses affect a unit's cost by more than just their defensive strength.

No Armor

 * Strength: 1

Psi Defense

 * Prerequisite: Eudaimonia
 * Strength: Psi
 * Cost: 6

Units equipped with a Psi Defense always engage in Psi combat when attacked, ignoring weapon and armor strengths. This is useful for defending against opponents whose weapon technology exceeds your defensive technology.

Synthmetal Armor

 * Prerequisite: Industrial Base
 * Strength: 2

Plasma Steel Armor

 * Prerequisite: High Energy Chemistry
 * Strength: 3

Pulse 3 Armor
''Same as Plasma Steel Armor, but more expensive and with +25% bonus vs. mobile attackers. Alien Crossfire only.''
 * Prerequisite: Adaptive Doctrine
 * Strength: 3
 * Cost: 5

Generally a bad choice of armor, since it costs just as much as Photon Wall, yet is less effective than Silksteel Armor even against mobile attackers. Still, it comes earlier in the tech tree than Silksteel, and might make the difference against an Impact Rover. Provides no benefit to ships except perhaps when defending in a base against a mobile land attacker, since ships are never mobile attackers. The AI prefers Pulse-3 Armor, which needlessly pushes up its unit costs. Disable it or decrease its cost to help out the AI.

Resonance 3 Armor
''Same as Plasma Steel Armor, but more expensive and with +25% bonus vs. Psi attacks. Alien Crossfire only.''
 * Prerequisite: Field Modulation
 * Strength: 3
 * Cost: 5

Mainly useful for combining with Hypnotic Trance on a foil for a great Psi defender. Other than that, see above.

Silksteel Armor

 * Prerequisite: Silksteel Alloys
 * Strength: 4

Photon Wall

 * Prerequisite: Photon/Wave Mechanics
 * Strength: 5

Probability Sheath

 * Prerequisite: Probability Mechanics
 * Strength: 6

Neutronium Armor

 * Prerequisite: Matter Compression
 * Strength: 8

Pulse 8 Armor
''Same as Neutronium Armor, but more expensive and with +25% bonus vs. mobile attackers. Alien Crossfire only.''
 * Prerequisite: Super Tensile Solids
 * Strength: 8
 * Cost: 11

Resonance 8 Armor
''Same as Neutronium Armor, but more expensive and with +25% bonus vs. Psi attacks. Alien Crossfire only.''
 * Prerequisite: Sentient Resonance
 * Strength: 8
 * Cost: 11

Antimatter Plate

 * Prerequisite: Matter Editation
 * Strength: 10

Stasis Generator

 * Prerequisite: Temporal Mechanics
 * Strength: 12

Fission Plant

 * Prerequisite Tech: N/A
 * Strength: 1

The default reactor for units. Later in the game, it is ideal for worm-killing units since psi combat ignores reactor strengths, and without a strong weapon, more advanced reactors will usually make the unit more expensive.

Fusion Reactor

 * Prerequisite: Fusion
 * Strength: 2

The first more powerful reactor you can get. The decrease in build costs is noticeable, and your units will be nearly unstoppable until your opponents discover Fusion as well.

Quantum Chamber

 * Prerequisite: Quantum Power
 * Strength: 3

Reactors beyond Fusion are of little use, since the game will probably be over by this point.

Singularity Engine

 * Prerequisite: Singularity Mechanics
 * Strength: 4

AAA Tracking
+100% defense vs air units.
 * Prerequisite: Advanced Military Algorithms
 * Cost: 1

Air Superiority
Allows a unit to attack air units in flight. Air units with Air Superiority gain a +100% combat bonus versus other air units but suffer a -50% combat penalty against ground and sea units.
 * Prerequisite: Doctrine: Air Power
 * Cost: 1

Algorithmic Enhancement
Improves probe team success rate and decreases probe attack energy costs. Also allows a probe team to attempt an attack on a base or unit under the Hunter-Seeker Algorithm, though at an extremely low success rate.
 * Prerequisite: Nanominiaturization
 * Cost: 1
 * Alien Crossfire only

Amphibious Pods
Allows ground units to attack sea bases, and allows ground units to attack from on board a sea-going transport. Also allows ground units to cross the gap between a friendly sea base and dry land without needing a transport in the base.
 * Prerequisite: Doctrine: Initiative
 * Cost: 1

Antigrav Struts
+1 movement rate for ground units, and ignore terrain movement penalties. An air unit with Antigrav Struts gains a movement rate increase equal to its reactor level.
 * Prerequisite: Graviton Theory
 * Cost: 1

Blink Displacer
Attacker ignores base defense bonuses.
 * Prerequisite: Matter Transmission
 * Cost: 1

Carrier Deck
Transport may carry air units.
 * Prerequisite: Nanometallurgy
 * Cost: 1

Clean Reactor
Unit does not require support from its home base. Not to be confused with the unit's Reactor, the Clean Reactor trait eliminates the cost of support. Note that probe and supply units inherently do not incur support costs, hence do not need this ability.
 * Prerequisite: Bio-Engineering
 * Cost: 2

Cloaking Device
Ground unit ignores zones of control (may move past enemy units without stopping).
 * Prerequisite: Frictionless Surfaces
 * Cost: 1

Comm Jammer
+50% defense vs. fast units (rover, hovertank).
 * Prerequisite: Advanced Subatomic Theory
 * Cost: Attack/Defense (rounded down, maximum 2)

Deep Pressure Hull

 * Prerequisite: Nanometallurgy
 * Cost: 1

Deep Radar
Unit can see two squares away instead of one. Note: units still cannot see into fungus (as sensor arrays do).
 * Prerequisite: Advanced Military Algorithms
 * Cost: 0 for air or sea units, 1 for ground units

Dissociative Wave
Halves all positive combat bonuses (such as the +25% defense against fast units conferred by the Comm Jammer special ability).
 * Prerequisite: Centauri Psi
 * Cost: 2

Drop Pods
Allows a unit to make an Airdrop over a range of eight tiles, instantly moving from the tile of origin to the destination, provided that there are no air defenses near the destination tile, that the unit has not moved yet this turn, and that the unit is starting from a friendly base or airbase. Upon discovery of Applied Gravitonics (or upon completion of the Space Elevator, whichever comes first) any units with Drop Pods may instead make Orbital Insertions, which removes the eight-tile restriction. A unit that has made an Airdrop or Orbital Insertion may attack on the same turn, but will suffer a -50% combat penalty.
 * Prerequisite: Mind/Machine Interface
 * Cost: 2

Empath Song
+50% to psi offense.
 * Prerequisite: Centauri Empathy
 * Cost: 2

Fuel Nanocells
Adds +2 to an air unit's fuel supply, effectively increasing its range by 1.
 * Prerequisite: Matter Compression
 * Cost: 1

Fungicide Tanks
Formers remove fungus at double speed.
 * Prerequisite: Synthetic Fossil Fuels
 * Cost: 1

Heavy Artillery
Ground unit can make long range bombardment attacks from up to two squares distant. It is important to note that artillery units are incapable of attacking any other way.
 * Prerequisite: Polymorphic Software
 * Cost: Armor+Speed-2 (rounded down, maximum 2)

High Morale
Unit gains one automatic Morale upgrade, in addition to any conferred by the unit's respective facility (ie. Command Center, Naval Yard or Aerospace Complex).
 * Prerequisite: Intellectual Integrity
 * Cost: 1

Hypnotic Trance
+50% to psi defense. This is probably the most popular special ability in the game, perhaps rivaling Clean Reactor, putting defending land units on equal footing with attackers, and turning sea or air units into veritable psi fortresses.
 * Prerequisite: Secrets of the Human Brain
 * Cost: Attack/Defense (rounded down, maximum 2)

Marine Detachment
Allows an attacking unit to capture a severely damaged enemy sea unit.
 * Prerequisite: Adaptive Doctrine
 * Cost: 1
 * Alien Crossfire only

Nerve Gas Pods
+50% attack bonus. Additionally, when attacking a city, kills half of the city's population (round up) if the attacking unit wins.
 * Prerequisite: High Energy Chemistry
 * Cost: 1

WARNING: using a unit equipped with this in combat is considered a Simple Atrocity. That means if the UN charter is in effect, sanctions will be imposed upon you (nullifying commerce for at least 10 years), and regardless of the UN charter, the opponent on whom you used nerve gas will hate you forever.

Non-Lethal Methods
Unit counts as two for police purposes (suppressing two drones instead of one).
 * Prerequisite: Intellectual Integrity
 * Cost: 1

Polymorphic Encryption
Doubles the energy cost incurred by an enemy probe team attempt to subvert the unit.
 * Prerequisite: Pre-Sentient Algorithms
 * Cost: 1

Repair Bay
Transport acts as a bunker (units heal while on board).
 * Prerequisite: Nanometallurgy
 * Cost: 1

Soporific Gas Pods
Unit reduces Morale of non-native enemy units by two when attacking.
 * Prerequisite: Bioadaptive Resonance
 * Cost: 1
 * Alien Crossfire only

Super Former
All terraforming orders except for Remove/Plant Fungus are executed at double speed.
 * Prerequisite: Advanced Ecological Engineering
 * Cost: 1