Marine commander

A practical guide to commanding marines: opening, economy, upgrades, supporting fights and closing games.

Your job in one sentence#

Keep the marines alive, armed and pointed at the right room, and make sure you have more extractors than the aliens have harvesters.

Drop an Extractor on the closest free resource node (and a second one soon). Send one or two marines to build each.
Build an Armory in the base, then an Arms Lab.
Research Armor 1 or Weapons 1 as soon as the Arms Lab is up. Against early skulk pressure, Armor 1 first.
Med pack marines who are fighting. A med pack (1 res) that wins a 1v1 is the best res you will spend.

Observatory → Phase Tech → Phase Gates. Gates let your team defend and attack anywhere. Put the first forward gate in a room with resource nodes.
Second Infantry Portal so lost fights don't leave the team waiting.
Shotgun research when fades appear; Mines and Grenades are cheap and useful.
Weapons / Armor 2. Keep the Arms Lab busy. Consider a second Arms Lab: if it dies, the upgrades switch off.
Scan before your marines walk into a room where you suspect a fade or onos.

Advanced Armory unlocks HMG, GL and Flamethrower and the Prototype Lab.
Jetpacks answer lerks and let marines reach hives fast. Exosuits break defended hives, but marines need the personal res.
ARCs with scans kill hives from the next room. Escort them.
Advanced Marine Support gives Nano Shield, Catalyst Packs and Power Surge for the final pushes.

Drop med packs on marines, not next to them. Ammo packs for marines that are reloading constantly.
Nano Shield the marine who is about to die, or the exo in front.
Beacon only when the base is truly about to fall. It pulls everyone home.
Watch the minimap for red blips: a skulk behind your team at an extractor is a 10-res problem in 20 seconds.