Tripple Barracks

The tripple Barracks build allows you to put early pressure on the opponent, and is very popular against Zerg. You will also have an army and economy that allows you to take your expansion. The build is safe against most rushes, and you can wall off to prevent the enemy from seeing your build.

The build requires you to get an early gas, but the Tech Labs and Marauders are cheap when it comes to gas, so you only need one in the beginning. You want a marine from your first Barracks to fend of any early zerglings or scouts. Keep producing Marauders from the Barracks with Tech Labs and Marines from the others. You can choose between getting a Reactor or researching Concussive Shells at about 30 supply. Remember to keep making Supply Depots, as your supply will quickly rise when you produce out of three Barracks. The best time to attack is when the Stim Pack and Infantry Weapons upgrades are finished, or a little while before that. You can also wait for Concussive Shells to be finished if you are going for that.

There are a few choices for transitioning from the trippel barracks opening. You want to focus on Marines and Marines, as you already have 3 Barracks up. You can go for a Starport for Medivacs, or make more Barrakcs. You can also have a few Siege Tanks to support the infantry. You can secure your expansion when you move out.