The All Terrain Armored Transport (AT-AT) was a large combat walker used by the Galactic Empire. They served as troop transports as well as artillery, and were an iconic symbol of the Imperial Army.
AT-ATs were virtually impervious to all but heavy artillery weapons. Walkers formed the core of many Imperial heavy ground assaults, often the first vehicles to leave their transport shuttle barges or drop ships and enter a combat zone. AT-AT walkers were used to crush and demoralize enemy forces. They also acted as transports for Imperial ground troops and light vehicles. A walker's movable "head" section contained the command cockpit, with room for the commander, pilot, and gunner, It also housed all the walker's weapons. Holographic targeting systems assist the gunners with a 360 degree view of their position.
The AT-AT's main weapons were two heavy laser cannons mounted on the chin. Two medium blasters were mounted on each side of the head. They could be independently rotated for different targets. The head could rotate as much as ninety degrees right or left and thirty degrees up or down for a large field of fire.
AT-AT walkers had an immense armored body section that carried five speeder bikes and up to forty troops. To unload troops, AT-AT walkers kneeled to three meters above ground level and sliding ramps from the main body section.
Beneath the main body section were the AT-AT's two immense drive motors. Four massive legs propelled the walker at a top ground speed of up to sixty kilometers per hour, although this was possible only on flat, stable terrain, while their immense size gave the illusion that they were slow, plodding vehicles.