Ghost Opening

The Ghost opening is a build specialized against Protoss, because of the EMP Shot. The Ghost with EMP combined with Marines can take out an army of Protoss Gateway-units, and even Immortals. Be careful if the Protoss is quickly getting Colossus, but you are safe against most other openings, both ground and air. Even Dark Templars can be EMPed, revealing them and allowing the infantry to take them down.

The build is based on getting a few Ghosts out as fast as possible. To do this you need the Ghost Academy. This is a gas-heavy build, requiring you take your second gas early. Put down a third Barracks with a Tech Lab when you can afford it, and put a Reactor on your other Barracks. This will allow you to easily transition to Marauders if you meet Colossus. You should attack when you have 2 or 3 Ghosts with EMP ready, in addition to an army of Marines. You might also want to research Combat Shield for your Marines.

The vital part of this build is that you hit most of the Protoss army with the EMP Shot. If you do, your forces will quickly be able to take them down and start taking down his base. Transition to MMM (Marines, Marauders, Medivac), Mech (Thor, Hellion) or Marines, Tanks and Vikings based on the opponents choise. Keep building Ghosts to send with your army no matter what strategy you are using, as the EMP Shot is useful against all types of Protoss units.