Research

Research Tree

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.

• 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
  • The Martian Solution

• Any Ethereal, or Sectoid Leader/Commander
  • Psionics/Psi Lab, which leads to psi-amp and mind shield

• Alien Commander
  • Cydonia or Bust *2

Notes

• 1 alien medics can give information on species other than their own
• 2 commander can be found in bases, or UFOs on Base missions, however, only commander from a base can be researched (?)

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