The Mothership is the most powerful unit in the Protoss arsenal: Once a Fleet Beacon has been built, it may be warped in at a Nexus. Because of its extensive capabilities, the Mothership has a unique restriction: only one can be deployed by each player at a time.

Although it does have an attack in the Purifier Beam, the primary use of the Mothership is its powerful support abilities. The Mothership has two spells, Mass Recall and Time Warp. The Mass Recall spell teleports player units in the target area to the Mothership after 4 seconds, just like the Nexus' Strategic Recall spell, but without any cooldown. The Time Warp spell slows down the units and structures in a targeted area. Furthermore, the passive ability Cloaking Field cloaks all nearby friendly units and buildings. While these abilities are powerful and potentially game-changing, the Mothership is very expensive, quite slow, takes a long time to warp in, and is only available at the end of a long tech path. Thus, the Mothership is generally only seen in late game compositions, although specialized builds can produce it earlier.