What is a Terran Wall ?
A terran wall is a defensive build where the player builds structures at the entrance of his main base.This denies early scouting from his oponent,and most importantly early rushes.
The terran wall is vital in every game,no matter the enemy race.The wall is especially crucial against zerg and protoss players.If a protos player can enter freely in your base early in the game,its ussualy game over.
His zelots will decimate your marines ,leaving you without any defense.Its even more crucial against a Zerg player,and here the speed at wich you wall off matters.
One of the most ways a Zerg wins early in the game is with the Zergling rush.Zerglings can run right into your mineral line ,bypasing any marine you might have and completely decimate your scv's.


