In the beggining, terran exiles (murderers, robbers and that shit) were sent to outer space. They colonized 13 planets and created a nation called the Confederacy (all this took many years... like 200). One day, the Confederacy knows of some strange alien organisms raiding planets. And 2 of the 13 Terran worlds fall to the Zerg, while battling with the Sons of Korhal in those planets.(a rebel group) And all I just explained to you happened in the Starcraft Beta version... That's were you start playing the campaign. Jim Raynor and his men are arrested by Edmund Duke, general of the Confederacy, commander of the Alpha Squadron, because Jimmy ordered his men to destroy an Infested Command Center. While Jim was still imprisoned, General Arcturus Mengsk (leader of the Sons of Korhal) rescues Jim and his men from the prison ship, but with only one condition: helping Mengsk on his goals of conquest. Jimmy meets Lieutenant Sarah Kerrigan, who is a Ghost. Mengsk orders Jim and Sarah to free the people of Antiga Prime from the iron fist of the Confederacy. Eventually, they succeed in this. While all this was happening, the innumerable Zerg raid more the Confederacy planets and the Protoss, under the command of Executor Tassadar, were after them, releasing massive planetary bombardements. All life upon the surface was extinguished. Mengsk, knowing that the advance of the Protoss could be harmful, orders kerrigan to protect the Zerg against the Protoss in a space platform, in order to save "humanity". Kerrigan succeeded, but was taken captive of the Zerg. Raynor refuses to follow and help Mengsk and escapes with his men.
Well... I have been typing for more than 30 minutes... I'll post more of this later... bye