The All Terrain Armored Transport, known more commonly by the abbreviation AT-AT, is an advanced vehicle available to the Imperial Remnant and Pentastar Alignment in Eras 1–5. It has an armament of 2 Laser Cannons.
AT-ATs were first produced by Kuat Drive Yards during the Clone Wars. They were evolved from the earlier AT-TE and AT-PT. The first-generation AT-AT saw its debut during the Battle of Jabiim, late into the Clone Wars. While they annihilated the overwhelmed Confederate forces, their significant decreased when the walkers' legs became mired in the mud, making them much easier to be brought down. During the Wars, wheeled tanks like the Juggernaut line were generally preferred over the legged AT-AT due to their decreased ground pressure.
During the reign of the Galactic Empire, the AT-AT was not forgotten, merely sidelined as the more popular Juggernaut was still the unit of choice among the Imperial Army. The most influential supporter of the AT-AT was General Maximillian Veers, who resurrected the AT-AT back into full Imperial service following the Battle Of Yavin. Three years after the Battle of Yavin, Veers had perfected a superior model. It was these that led the attack on the Rebel base on Hoth. Though the unstable terrain and Rebel tactics led to several walkers being lost, the overall mission was a success.
Sometime after the Battle of Endor, the Empire replaced the standard weaponry of some of the walkers with 2 light turbolasers. During the Reborn Emperor's campaign against the New Republic, a new version of the AT-AT with the most powerful Imperial turbolasers was produced. AT-ATs would remain in service to the Imperial Remnant and the breakaway Warlords throughout the Imperial Civil War, with many seeing battle during the Yuuzhan Vong War. It would serve as the basis for the All Terrain Armored Heavy Transport of Darth Krayt's Galactic Empire, but even the AT-AT itself would see use by it.
The AT-AT is the ultimate Imperial weapon. Strong, durable, immovable, heavily armed, and with a range that far exceeds that of most non-artillery, it is the centerpiece of any Imperial invasion force. If the AT-AT cannot immediately outgun its opponent, chances are it can outlast it, with a single AT-AT able to outlast a Turbolaser Turret in a one-on-one encounter. At least one of these should be in every invasion force. If possible, they should be deployed in pairs.
While the Pentastar Alignment also can build AT-ATs, they are not as reliant on them as is the Imperial Remnant. Although lacking the brute firepower of the AT-AT, the much more flexible Floating Fortress is often the better choice. Pentastar ground forces focus on flexibility and a multi-role approach; the AT-AT does not fit in with this mentality.
The primary weakness of the AT-AT is its slow speed, horrendous turning radius, and fixed firing arc. It can easily be overwhelmed by a mass of infantry, and if you can blind spot it, it will fall. Thus, it is important that the AT-AT is always escorted by smaller, more mobile units such as the AT-ST, TIE Crawler, and infantry. In short, the AT-AT is the centerpiece of the Imperial Remnant ground forces, and should be used like a battering ram against any enemy opposition.