Compiled overview of the 100 ton Atlas 'Mech, from various BattleTech novels and game sourcebooks:

The sight of BattleMechs lumbering across the terrain is a familiar one among the worlds of the Inner Sphere. Nevertheless, the sight of an Atlas still manages to make even experienced MechWarriors break out in a sweat. The AS7-D Atlas was designed as a last-ditch attempt to ensure the superiority of the Star League's Regular Army over the growing armies of the House Lords. General Aleksandr Kerensky himself set down the specifications for the Atlas, calling for "a 'Mech as powerful as possible, as impenetrable as possible, and as ugly and foreboding as conceivable, so that fear itself will be our ally."

Ugly and foreboding are two apt descriptions for the Atlas. Though some 'Mechs might be taller and heavier, none have the Atlas's aura. Considerable effort went into making the Atlas's weapons as visible as possible to give an opposing MechWarrior plenty of opportunity to see that he is out-gunned, and not being paid enough to die. Designers spent an entire year fashioning the head/cockpit to create a perfect merging of function and gruesomeness. The end result resembles a mechanized headless horseman with his jack-o-lantern skull. The design is accentuated by huge stooping shoulder cowlings and a hunched back with every line leading the eye inward towards the machines frightning visage. MechWarriors nicknamed the Atlas "Death's Head".

The AS7-D Atlas was one of the first 'Mechs to mount such a large and devastating gun as the Defiance 'Mech Hunter Class 20 Autocannon. Even though it carries only ten rounds of ammo, the mere threat of such a large cannon is often enough to send lighter 'Mechs scurrying. This weapon's only problem is that it lacks a cooling jacket and can overheat easily.

The Atlas's long-range missile delivery system is a unique design. Upon discovering that the twenty launching tubes of the Far Fire LRM-20 would not fit into the 'Mech's torso, the designers modified the launcher to use only five tubes with a feed system that can shoot four salvos within ten seconds. The feed system is fairly reliable, and techs need only worry about shielding the ammo from heat emitted from the nearby reactor. Reloading is quick, as each missile tube has its own ammunition clip. Completely loaded, the missile system can shoot twelve salvos of twenty missiles.

The 'Mech's armor is thick, and the forward torso and legs are especially well protected. Someone once calculated that if a battalion of Stinger 'Mechs engaged an Atlas, the Atlas would retire for repairs an hour later, leaving only one Stinger still able to move.
(...uhm, ya, right! The Atlas does pack an impressive 19 tons of Durallex Special Heavy Armor, but this guy was just kissing General Kerensky's ass. No one 'Mech can withstand a battalion of anything. Fuck, just ask an Ewok!)

Four Defiance B3M Medium Lasers and a TharHes Maxi short-range missile 6-pack make the 'Mech a decent close-range fighter, but it's true close-range weapon is it's mellee ability. The Atlas' strong Foundation Type 10X internal structure gives the arms and hands enormous power. This has created many horror stories concerning Atlases lifting light sized 'Mechs with one hand and fling them to the ground as though they there were mere toys.

The main drawback of the Atlas is its slow speed. Intelligent opponents will retreat before the forbidding machine, hoping either to draw it into tight quarters, such as a city or woods, or sucker it into water or mud. Once there, the Atlas's lack of mobility and jump jets is a fatal flaw.

The AS7-K Atlas is a formidable new re-design that incorporates an extra-light engine, Cellular Ammunition Storage Equipment, and an impressive array of weapons.

The AS7-K trades the Class 20 Autocannon for a Dragon's Fire Gauss rifle. The arm mounted medium lasers have been upgraded to Victory Nickel Alloy extended-range large lasers. The two rear-facing, torso mounted mediums are now Victory Heartbeat medium pulse lasers. The Yori Flyswatter anti-missile system complete the design's arsenal. the only sacrific for these upgrades was the scraping of the short-range missile 6-pack. That, and the price tag jumped from 9.5million to over 22.5!

The Atlas was first used against Stefan the Usurper. In the final battles to gain control of Earth's major spaceports, the Atlas was instrumental in securing beachheads to allow troops to land safely.

General Kerensky's second-in-command, General Aaron DeChevilier, spearheaded the final assault on the Usurper's last stronghold, the Imperial City. He continually exposed his Atlas to enemy fire, yet marched on as if the laser bolts, missiles, and cannon shells were nothing more than the annoying buzz of flies. When DeChevilier's Atlas pushed over the concrete outer wall surrounding the Imperial Palace, Kerensky headed for the Usurper's palace gates in his Orion.

Considering the Atlas's raw power, it is no wonder that Kerensky wanted all Atlases to accompany him into his self-imposed exile. Ironically, more than two thirds of the pilots who refused to join him were Atlas pilots. The remaining Atlases (and those still being produced by Yori Mech Works and Independence Weaponry on the planets Al Ma'ir, Hesperus and Quentin) continue to inspire terror wherever they tread.

Note: Information used here was the domain of FASA before they split the rights between Wizkids LLC and Microsoft (table-top gaming and video games respectively). Copyright of the fluff text is in limbo, but names of persons, places, & things are without any doubt the property of Wizkids LLC. Use of any terms here related to the BattleTech trademark are not meant as a challenge to Wizkids LLC's rights.