The Advanced Construction Bot can build Tech 2 structures and opens the door to an advanced economy.

Start by building Advanced Metal Extractors and a Fusion Reactor.

It's quite slow and weak, so try to escort it with a few defensive units. Each Tech 2 constructor also increases the player's energy and metal storage capacity by 100.

Mobile constructors produce a small amount of energy, helping you scale economy just by having them alive. Construction Turrets do not do this.