The AT-AT is one of the most powerful surface vehicles to ever be constructed and not to mention, one of the largest. The AT-AT was designed to be used on any terrain on many different worlds and to match terror inspired by Imperial Star Destroyers and Stormtroopers. The Empire has countless repulsor vehicles, however the drive systems of these vehicles could be overcome by gravity fluctuations, unusual planetary magnetic fields, and or other special planetary conditions. Designers turned to older technology which was limited in use in older vehicle designs, such as the AT-PT. The "walker" designs were previously (in the Old Republic) not used on a large scale. At first, Imperial officers ridiculed the AT-AT, but their laughing came to an end when these mighty weapons of war proved themselves on the battlefield and surpassed Imperial expectations. Almost virtually unstoppable as weapons of war, they were impervious to all but heavy artillery weapons. Blaster bolts from ordinary turrets and cannons merely glance off the armour or are harmlessly absorbed and dissipated by it. Thus meaning it's armour is virtually impervious to blaster fire. A repeated concussion missile assault will penetrate the armour, however. AT-ATs proved to be potent and powerful psychological weapons due to their colossal size and their nightmarish animal resemblance combined with its combat strengths.

    These walkers formed the core of many heavy ground assault units, often the first vehicles to leave their transports to enter in combat. In combat they can crush and strike fear in defending armies and even the most battle hardened troops fear the AT-AT. These metal monsters can crush anything and everything that is in their path with its massive durasteel feet. The stomping footpads of the AT-AT can cause the ground to shake before they even appear to the enemy, thus frightening and demoralizing the enemy. Until the Battle of Hoth, no army had ever fought resolutely against an onslaught of AT-ATs. A powerful reactor produces the raw energy needed to move this weighty walker. These walkers are capable of marching through most defences. The height of the vehicle allows the crew to view over obstacles that would interfere with other smaller combat vehicles, such as trees or low buildings that would be encountered during urban battle situations.

    The "head" section holds all of the weapons and contains the command cockpit for the crew. Holographic Targeting Systems assist the gunner with a 360 degree view of the battlefield. These battlescan images can be viewed by the electrorangefinder (pull-down periscope) or it can be superimposed upon the view port. The "head" section can rotate 30 degree arcs vertically and 90 degree arcs horizontally. The Pilot and the Gunner (Co-Pilot) can peer over the battlefield through the transparisteel view port and are supported by many sensory and targeting devices on board, thus providing the pilots a superior view of the battlefield around them. Both pilots are fully qualified to perform all control functions, in normal practice one serves as the driver, while the other serves as the gunner. Firing controls at any time can be yielded to the vehicle commander who stands at the combat co-ordination station, which is behind the pilot stations. The pilots are guided by terrain sensors located under the cockpit and terrain scanners and impulse terrain sensors built into the feet of the walker. The scans read the nature of the terrain ahead, assuring infallible footing. An armoured flexible tube connects the "head" section to the body, it acts just like a neck. The neck consists of ringed electromagnetic systems which enable the neck to flex.

    To disembark troops the AT-AT kneels to three metres above ground level, sliding ramps on the main body extend to the ground, so battle ready troops "hit the ground running," weapons drawn, they are shielded from enemy fire by the AT-AT's main body. There is a second way to deploy troops from the walker. The walker comes equipped with extensible deployment cable racks. At each of the deployment hatches are three of these cable racks. Troopers strap themselves in the deployment harness and are winched down by a high-speed cable winch, which allows the walker to deploy troops in several rapid waves. Equipment and speeder bikes can be deployed in this manner as well. Beneath the main body are two immense drive motors that propel this metal beast. The side hatches on the main body are Escape Hatches, so if there is an emergency, personnel can get out of the walker. Those hatches are also used for access to the walker via boarding ramps of Imperial Landing Platforms.

    Some of the few weakness of the AT-AT are: when balance is lost it cannot be regained and the "neck" section is susceptible of being to repeated attack, this is were vital linkages run. The AT-AT has Atmosphere Exchangers and a Filtration Unit located in the aft of the walker. The body of the AT-AT consists of two decks. The upper deck consists of two compartments. The compartment behind the "head" of the walker  is the troop compartment. The troop compartment contains troop benches which are equipped with backpack charger units for each trooper and has a drop down harness to hold the trooper in place. To get to the deployment deck, troops must climb down a ladder on the aft wall of the compartment. Behind the deployment compartment is the speeder bike garage. Behind the troop compartment is the fuel cell that powers this behemoth. The deployment deck also contains the some troop benches, which are the same configuration as those found in the troop compartment. At the very top of the walker's body is the atmospheric intakes. The three slots on either side of the walker, between the shoulder joints for the legs are heavy braces, which at those three points lock the AT-AT into their landing barges.

    AT-ATs usually carries a set of speeder bikes for scouting or survivor-hunting missions. The speed and agility of the speeder bikes complement the walkers, making the combined assault capability thorough and overwhelming. The AT-ATs used at the glorious Battle of Hoth were specially modified cold-weather AT-ATs. While they have the all the outside appearances of an ordinary AT-AT, these walkers had specially designed heat circulation systems, de-icing controls and energy efficient environmental controls. However, ordinary AT-ATs perform well in desert, forest or snow conditions.