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).

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.

Infantry

 * Prerequisite: N/A
 * 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.

Weapon
'Copters, Gravships, Hovertanks, Infantry, Needlejets, and Speeders all equip weapons. Missiles (and only missiles) carry Missile Payloads. Mind Worms carry the Psi Attack weapon. Units with any other chassis must equip Equipment instead of a Weapon.

Hand Weapons

 * Prerequisite: N/A
 * Attack Strength: 1

This weapon is really no weapon at all: when a unit has no other weapon, it will use this.

No Armor

 * Prerequisite Tech: none
 * Defense Strength: 1

Pulse-3 Armor
Prerequisite: Adaptive Doctrine

''Same as Plasma Steel Armor, but more expensive and with +25% bonus vs. mobile attackers. Alien Crossfire only.''

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.

Pulse-8 Armor
Prerequisite: Super Tensile Solids

''Same as Neutronium Armor, but more expensive and with +25% bonus vs. mobile attackers. Alien Crossfire only.''

Resonance-3 Armor
Prerequisite: Field Modulation

''Same as Plasma Steel Armor, but more expensive and with +25% bonus vs. Psi attacks. Alien Crossfire only.''

Resonance-8 Armor
Prerequisite: Sentient Resonance

''Same as Neutronium Armor, but more expensive and with +25% bonus vs. Psi attacks. Alien Crossfire only.''

Fission Plant

 * Prerequisite Tech: N/A
 * Hit Points: 10

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.

Clean Reactor

 * Prerequisite Tech: Bio-Engineering

Not to be confused with the unit's Reactor, the Clean Reactor trait comes with Bio-Engineering and while it increases the costs of the unit's construction, it reduces the cost of support.

Deep Pressure Hull
Allows teh unit to function as a submarine.

Hypnotic Trance

 * Prerequisite Tech: Secrets of the Human Brain

This is probably the most popular special ability in the game, perhaps rivaling Clean Reactor. Adds 50% to psi defense, putting defending land units on equal footing with attackers, and turning sea or air units into veritable psi fortresses.

Nerve Gas Pods

 * Prerequisite Tech: High Energy Chemistry

WARNING: using a unit equipped with this in combat is an atrocity. That means if the UN charter is in effect, everybody will declare war against you. You have been warned.

+50% attack bonus.