NS2:FA - Marine Techtree

Marines advance through their techtree by building tech buildings (Armory, Observatory, Prototype Lab). When a building finishes construction it starts researching upgrading itself and all other structures of the same type. Research costs material and will continue as long as there exists more structures than current research level. The current research level is always maintained despite destroyed strucutres, but is temporarily disabled if all structures of that type is destroyed.

Research of different types may be done concurrently.

(ex. Current Armory research level is 2, and a third Armory is built, research is immediately started on the next level. If any Armory is destroyed before it is complete, research will be halted until another is built. But the current research level is maintained except if all Armories are destroyed)

Armory
Rifle - Standard Issue. Default weapon for Soldiers.
Catalyst pack (Rifle add-on) - One time use, gives an attack rate increase for a short while. Requires level 1.
Shotgun - Does large damage in bursts. Sprint slightly faster. Requires level 2.
Flamethrower - Damages energy as well as armor, leaves a burning effect that makes aliens take damage over time until healed. Disables alien structures while under constant exposure. Requires level 3, and 2 CCs.
Grenade Launcher - Fires a projectile that explodes after 2.5 seconds. Friendly fire. Very effective against structures. Does not detonate on impact. Also a Rifle with a much smaller clip. Requires level 4 and 2 CCs.
Plasma Repeater - Energy minigun, takes a while to charge up, but fires quickly and narrow while limiting turning and movement. Reloads using Plasma instead of carried ammo. Requires level 5 and 3 CCs.

Observatory
Supply Dispenser - Drops medpacks/ammopacks at target. 2 Charges, takes a few seconds to recharge. Requires level 1.
Scanner - Use to scan at engineers current position. Reveals aliens and structures.through obstacles/walls. 1 Charge, takes a while to reload. Requires level 2 and 2 CC's.
Mines - 2 one-time use proximity mines that does heavy damage. Requires level 3 and 2 CCs.
Atmospheric Upgrade - Increases armor, and slightly increases movement speed of all marine players. Requires level 4.
ARC Designator - A mobile siege gun follows you around and positions by your laser designator. While sieging does heavy damage to structures revealed through sight or scanning. Requires level 5.

Prototype Lab
Weapons Upgrade I - Increases damage done by most weapons. Requires level 1
Weapons Upgrade II - Further increases damage done by most weapons. Requires level 2
JetPack - Allows aerial movement, immunity to gas - Requires level 3 and 2 CCs.
Weapons Upgrade III - Increase damage done by most weapons even further. Requires level 4.
Heavy Armor - Greatly increases armor but decreases movement speed. Requires level 5 and 2 CCs.