Photon cannon

"Whoa! Careful of those protoss cannons! They can detect banshees even when they're cloaked!"

- Rory Swann

The photon cannon is an automated defense structure of protoss design. Although the protoss revel in the glory of personal combat, they also recognize the need for automated defenses. As such, the cannon fires an encapsulated antimatter sphere similar to that generated by the dragoon, which can target air and ground targets. They are enhanced with special sensor technology borrowed from the observer. Photon cannons require a link to the psionic matrix generated by pylons.

Strengths

 * Inexpensive
 * Easy to deploy
 * vs ground & air

Weaknesses

 * The can use the Yamato Cannon to destroy it at a safe distance as well as other long range units such as guardians.
 * Large numbers of units like zerglings or s can take the cannon out, as it isn't very efficient against multiple foes.
 * High damage foes, like archons or ultralisks, can deal large amounts of damage faster than the cannon can.
 * Without pylons the protoss have no automated defenses.
 * As with all protoss units and buildings, EMP shockwaves from science vessels can render them without shields.

Development
During the StarCraft alpha, the photon cannon was known as the "photon battery."

StarCraft II
The photon cannon re-appears in StarCraft II, much the same as its predecessor.

Co-op Missions
Karax is able to upgrade his photon cannons and warp them in instantly in Co-op Missions once he reaches Level 6.

Development
The photon cannon initially structuraly resembled its predecessor, retaining its 'telescope'. It was replaced by the phase cannon early in the development of StarCraft II. It has since returned in name and ability, although uses the phase cannon's model.