Guardian cannon (Tiberium Wars)

The Guardian cannon was a defensive anti-tank turret in the used by GDI during the Third Tiberium War.

Background
The Guardian cannon was armed with a powerful 105mm cannon protected by a forward-facing shield and mounted on a rotating platform capable of traversing the turret 360 degrees horizontally and 30 degrees vertically. The cannon itself fired large-caliber APDS rounds. It was effective against light to medium vehicles, but required support against infantry, aircraft, and heavier vehicles. However, the Railgun upgrade improved the Guardian cannon's damage significantly, allowing it to cope with heavy armor. The Battle Base also incorporated two Guardian cannons into its defenses.

Game structure
The cannons are a good anti-tank defense, powerful though not as deadly or versatile as Nod's Laser Turrets. However, in Kane's Wrath, GDI and Steel Talons Guardian Cannons can be upgraded with Railguns, making them a viable defense even in the late game. Guardian Cannons can detect stealth units, so they are capable of being a good deterrent to Stealth Tank attack, as well as being able to support nearby units and base defenses in finding hidden enemies.

In Tiberium Wars, the Guardian Cannon has sluggish firing speed coupled with mediocre damage, making it less viable than the Predator tank even for defense. However in the Kane's Wrath expansion pack, the Guardian Cannon's firing rate has been doubled, turning it into a much more effective base defense. The cannon still suffers from a relatively short range, being, like any base defense, vulnerable to artillery. Long ranged units such as the Devourer tank and Avatar Warmech are also safe from Guardian Cannon fire. It is prone to being overwhelmed with masses of vehicles (though so are the equivalent basic anti-vehicle structures of the other factions), is easily outgunned and is generally cost-ineffective against heavy assault vehicles like the Annihilator Tripod or Mammoth Tank, hardly damages most infantry types, and lacks any any anti-air capability. Guardian Turrets tend to be unpopular with GDI commanders since their Predator tanks already can outgun enemy armor early on, are mobile, and do not require power to operate, although they do not have the sheer armor and firepower of the Guardian Turret; investing in more tanks which are adequate for both defense and offense takes priority over sheer defense in many circumstances. In the early game, however, it can still be an important defense, particularly in GDI-on-GDI battles, where both sides are more likely to take an armor-superiority approach to victory and the Guardian Turret's cost effectiveness on defense will come into play.

The standard Guardian Cannon can be reliably described as one of the less effective base defenses in the game, typical of GDI designs; GDI tends to supplement their base defenses with their vehicular superiority in armor and firepower. It is still a cost efficient defense against mid-level units such as regular tanks (except for Devourer Tanks, which outrange it) and light vehicles, however, providing that it isn't being overwhelmed. If it is upgraded to use Railguns it becomes markedly more effective, making it a very good defense against light and medium units and decent against heavy ones, while giving it some noticeable ability to kill infantry.

Development
In the game files, it sometimes referred to as the Golem cannon.

Changelog

 * Tiberium Wars patch 1.05:
 * now cannot miss against moving enemy vehicles.
 * added recoil effect
 * Kane's Wrath patch 1.02: damage increased from 175 to 200

Trivia

 * The Guardian Cannon's buildup animation does not play at all when the game's animation quality settings are set to low. For the animation's duration, the cannon is completely invisible.
 * The Auto-Turret from StarCraft II bears a striking resemblance to the Guardian Cannon.