Research

Research Tree

You are given Laser weapons, Medi-kits, and Motion Detectors as research topics at the start of the game. Every subsequent research topic stems from a breakthrough in a previous research topic, or new technology picked up on the battlefield and brought back to your stores. (You can sell off the item from your stores once research has started, if you need the space.)

Laser Weapons

Laser Weapons  (tech breakthrough)
  |
Laser Pistol
  |
Laser Rifle
  |  
Heavy Laser       
  |  
Laser Cannon 
(Laser Tank)    
  | 
Laser Defense 

Plasma Weapons

    Heavy Plasma               Plasma Rifle 
         |    Heavy Plasma Clip   |  Plasma Rifle Clip  
         |___________|            |__________|
                 |                       |
                 |                       |
                 |__________OR___________|
                            |
                    Plasma Cannon
              (Hovertank/Plasma)*1
                            |
                   Plasma Defense

Fusion Weapons

 Blaster Launcher    Blaster Bomb
             |___________|
                  |
                Fusion Ball
                (Hovertank/Launcher)*2
                  |
                Fusion Defense

Armor

      Alien Alloys
              |  
Elerium-115  Personal Armor  UFO Power Source      
|_____________|_________________| 
          | 
          |     
     Power Suit      UFO Navigation  
          |_________________|   
                   |
             Flying Suit 

Craft

Alien    Elerium        UFO            UFO
Alloys      115     Power Source   Navigation
|___________|___________|______________|
           |
   UFO Construction
           |
           |
   New Fighter Craft
      (Firestorm) *1 = [Hovertank / Plasma]
           |
New Fighter-Transporter
      (Lightning)
 __________|____________
 |                      |
Grav              Ultimate Craft
Shield               (Avenger)

Notes

• 1 Need "New Fighter Craft" before you can build the plasma

hovertank.

• 2 Need fusion ball launcher before you can build the fusion ball

hovertank.

-- from Kasey Chang's USG

Live Alien Research

Researching live aliens gives different results depending on their rank. It is very important to take certain aliens alive to finish the game. Picking your aliens becomes easier with the Mind Probe and Small Launcher, although a well-applied Stun Rod early in the game can give your tech tree a big boost. Note you not only need to have an unconscious alien when you exit the Battlescape, you also need an Alien Containment module at the base your craft returns to, or they'll die before you get any useful info.

• Any Live Alien
  • Alien Origins
• Alien Soldier
  • Alien missions (harvest, base, etc)
• Alien Medic
  • Species information *1
• Alien Navigator
  • Hyper-Wave Decoder

• Alien Engineer
  • UFO stats (of that UFO)

• Alien Leader (or Commander)
  • The Martian Solution

• Alien Commander
  • Cydonia or Bust *2

• Any Ethereal, or Sectoid Leader/Commander
  • Psionics (see below)

Notes

• 1: Alien medics can give information on species other than their own
• 2: Commanders can be found in bases, or UFOs on Base missions, however, only commander from a base can be researched. (Any species of alien commander will do - Cydonia or Bust requires The Martian Solution, and that in turn requires Alien Origins)

Psionics

Psionic Alien
  |
Psi Lab
  |  \
Psi-amp Mind Shield

Endgame

Any Live Alien
 |
Alien Origins
 |
 | Any Live Alien Leader
 | /
The Martian Solution  
 |
 | Any Live Alien Commander
 | /
Cydonia or Bust
 |
 | Avenger
 | /
Cydonia (mission)

-- from Kasey Chang's USG