A Detector is a unit or structure with the ability of Detection: it is able to reveal cloaked, permanently cloaked, burrowed, or hallucinated enemy units. Having enough Detectors across the map is an important aspect of any player's strategy, as they will provide intel on potentially fatal attacks from otherwise unstoppable hidden units. While every race has a mobile detector unit, they also have a passive defense building that provides detection, such as Photon Cannons, Spore Crawlers, and Missile Turrets. Detector buildings lack the mobility of units, but make up for it by being much more durable and by being equipped with a weapon. Regardless of which race a player uses, if the opponent uses cloaked or burrowed units, having a Detector in your army before engaging your opponent is pivotal.
Units in Starcraft II are tagged with one or more Attributes that determine bonus damage, affect targeting, and/or can influence spells and abilities.
- Raven (range 11)
- Ghost's EMP Round reveals cloaked, but not burrowed units. (range 10, radius 1.5)
- Orbital Command ability Scanner Sweep (radius 13)
- Missile Turret (range 11)
- Note that the Xel'Naga Tower does not have the Detector ability.
- Terrans' Sensor Tower does not detect.
- The Protoss detector, the Observer, is also a valuable scouting unit with the ability to reveal enemy game-play decisions.
- Although detection is tied to a unit's sight range, it will provide detection within that range when its own line of sight is blocked as long as vision is provided by another unit, e.g. Missile Turret at the bottom of a ramp with a Marine on top of said ramp; this will detect Dark Templars on the upper cliff level.