Ghosts epitomize the height of terran evolution and physical conditioning. Born with incredible psionic potential, these individuals are recruited and quarantined for government training from childhood. Ghosts channel their psionic energies to augment their natural physical strength and endurance. This process is enhanced by specialized skin-suits worn by ghosts that are laced with a form of psi-sensitive artificial muscle fiber. Thus, a typical ghost is tougher, stronger, and faster than even a well-trained but otherwise average terran.

Exceptional ghosts exist that can tear through walls, run at remarkable speeds, and leap tall obstacles. Excitable media rumors of long-range telepathy, telekinesis, and even mind control or other exotic powers have all added to the grisly reputation of ghosts cultivated by their masters.

As a precautionary measure, neural inhibitors are surgically implanted in all ghosts to prevent such deadly individuals from going rogue. The effectiveness of this measure is questionable, however, for there are whispered tales of ghosts working outside governmental authority. Most infamously the current leader of the zerg Swarm, Sarah Kerrigan, was originally a ghost loyal to Arcturus Mengsk prior to her capture and infestation with the zerg hyperevolutionary virus.

On the battlefield, ghosts are rightly feared for their preternatural sniping ability with the C-10 canister rifle. An unwieldy weapon in the hands of others, the C-10 is capable of a one-shot kill when used by a ghost. Tactically ghosts’ primary responsibility is to locate enemy structures or units and eradicate them by calling down drop-pods or tactical nuclear weapons. The C-10 is equipped with an underslung low-frequency laser to pinpoint targets of such strikes.

The most unnerving skill of these agents is their ability to cloak themselves from enemy sight. This "invisibility" has earned ghosts a fearsome reputation for their mysterious battlefield tactics. The psionically powered personal cloaking device is a special-issue item only available by request. Once equipped, the device meshes with the ghost’s hostile environment suit so that with an effort of will, the operative becomes entirely undetectable without the aid of specialized sensory equipment.