IMPORTANCE OF BUILDING PLACEMENT
Author: Daktakpaklak

COUNTERING THE EARLY RUSH

Being able to survive an early rush is an important part of playing StarCraft.  There are several elements to averting a rush which are well known: knowledge of the imminent attack (reconnaissance), a quick and well-executed build-order, and unit-targeting micromanagement are several important aspects of rush-defense. A counter-rush strategy which is much less-frequently observed is using building presence as a defense. Essentially, this idea involves physically obstructing enemy units with other structures. The Terrans are best able to capitalize from this tactic, as they are the only race with ranged units in the early stages of the game; Marines can fire at enemy attackers who are forced to run around the buildings to attack.

On a land map, the first four buildings built by a Terran are generally two Barracks and two Supply Depots. These are all cheap, large buildings with a high number of hitpoints. Build these early structures in a semi-circle a short distance from your Command Center. Position them as close together as possible, but be sure not to obstruct SCV production. Set the Barracks' rally points between the Command Center and the structures, and then pump out some Marines.

Any enemy rushers wishing to target the Marines or SCVs must now walk all the way around the buildings before coming in range.  During this time, of course, your Marines will be scoring free hits. This tactic is also an effective way to combat Dark Templar; by placing a Missile Turret at the center of your compound, there's no way Dark Templar will be able to reach the vulnerable workers. To extend your infatry's range of fire, construct the blockading buildings a bit further out from the Command Center, and build a Bunker in which to house them.

NOTE: Obviously, the ranged weapons of enemy Marines prevents them from having to circumvent the structure line. This makes Bunkers a must if facing a Terran opponent, both to increase your Marines' range and to keep them healthy.