Static Defense, sometimes colloquialized as static d, is any immobile object that provides defensive combat capabilities, most commonly referring to buildings. Dedicated buildings require no supply and have vital statistics more cost effective than training army units. (The Bunker is somewhat of an exception, since it has no attack capabilities on its own and requires supply-consuming units inside.)
Being immobile, static defenses only operate in an certain area. Static defenses are often used to fortify a position which cannot be abandoned without serious consequences. A real game application of this could be defending from a rush or pressure play in the early game while attempting to quickly tech up. Common tactics to bypass static defense include drops and other means that allow units to get to a target without being attacked, or simply attacking them with specific offensive units that out-range them (available to all races at a certain tech progression).
"Static Defense" can also be used in a variety of offensive strategies.
- Missile Turrets require an Engineering Bay and provide anti-air static defense and detection capabilities.
- Bunkers require a Barracks. They do not provide combat capabilities on their own, but rather enhance the defensive capabilities of Marines, Marauders, Reapers and Ghosts. Occupants may still attack, and their range is increased by 1. Bunkers may be Salvageed for 75% of their original cost.
- Planetary Fortresses can be upgraded from the Command Center once an Engineering Bay has been made. They are the only static defense with an area of effect attack.
- Siege Tanks, although able to move and shoot while unsieged, may be considered static defenses while in Siege Mode.
- Auto-Turrets and Point Defense Drones, summoned from a Raven, serve as temporary static defenses.
- Photon Cannons are the main static defense of the Protoss. They detect and can attack ground and air units. They require a Forge. Photon Cannons must be built within the Psionic Matrix and become inoperable if the matrix is removed for any reason.
- Photon Overcharge (casted by the Mothership Core) is another temporary source of static defense. In Heart of the Swarm, it had the same damage and weapon speed as a Photon Cannon, but has range 13 instead of 7. (Note: Nexus sight range is only 11.) In Legacy of the Void, it has the same range as a Photon Cannon, but a damage of 30 instead of 20.
Both forms of Zerg static defense must be made on creep and have the ability to uproot, move and reroot in a new location. They can only attack and detect while rooted.