Liberty Prime

Liberty Prime is a U.S. Army pacification robot. He is put back into service by the Capital Wasteland Brotherhood of Steel after they find him in the basement of The Citadel. (This is, presumably, the "technological marvel" mentioned in the Brotherhood's faction profile.) He was originally designed to aid American troops in the liberation of Alaska from communist China. However, he was not completed on schedule, and America was forced to fight a long bloody battle using their other secret weapon, the more successful and reasonably-scaled Power Armor.

He requires a massive amount of power to operate, as the Brotherhood of Steel was long unable to power him properly even with the advanced tech discovered inside the Pentagon. His large backpack holds a seemingly inexhaustible supply of Mini Nukes, which he can remove and hurl at enemies like a quarterback throwing a pass. He is also equipped with twin head-mounted lasers, much more powerful than a standard Laser Rifle. His massive size and strength count as weapons too: he is endowed with strength befitting a forty foot tall robot, and can rip anything in his path to shreds... if he doesn't step on it first. He also appears to have an Energy Shield, as he can sustain massive amounts of damage and short out energy barrier fields by forcefully walking into them. Finally, to inspire his allies and demoralize foes, he constantly spouts anti-Communist phrases (like most of the servitor/combat robots in the game, he seems to 'think' that he's still in the pre-Fallout years prior to 2077).

Through the computer terminal at the foot of the Liberty Prime, it is revealed that the project was commissioned by General Constantine Chase, and is a joint effort between the U.S. Army, General Atomics, and RobCo.

It would be a difficult proposition, at best, for the Player character to get through the gauntlet of hordes of Enclave troops, Power Armors, and (armed) VTOL aircraft without the fire support of the giant robot, and it is impossible for the player to proceed further towards the Jefferson Memorial after the Enclave secures it (without exploiting glitches in the program), as the area is closed off by several sets of otherwise impenetrable force-fields that only Liberty Prime can neutralize.

Visual Appearance
Liberty Prime is a massive, forty foot tall war robot stored in the basement below the Citadel. It's humanoid in shape, and it somewhat resembles The Iron Giant 1999, but possesses the head (and laser vision) of Gort from the 1951 version of The Day the Earth Stood Still.

Appearances
Liberty Prime appears only in Fallout 3. He is first seen in the lab underneath the Citadel, in his inactive state. During the events of Take it Back!, the Brotherhood of Steel, with the cooperation of Dr. Madison Li managed to reactivate the robot, who then proceeds to clear the way for Lyons' Pride to the Jefferson Memorial, where he remains until the end of the game (despite the sense of urgency imparted to the player, Liberty Prime appears to be indestructible and entirely capable of defeating the Enclave all by himself with little or no interaction by the player).

Trivia

 * Liberty Prime's name is a possible reference to Optimus Prime, of Transformers fame, as their voices sound remarkably similar, and Optimus Prime's most common motto is "Freedom is the right of all sentient beings", similar to Liberty's patriotic battle cries of pro-Democracy. Liberty Prime's battle dialogue is often quite humorous, even given the desperate circumstances. For example, while shooting down multiple Enclave Vertibirds like a human would swat at flies, Prime declares in his booming voice that "Death is a preferable alternative to Communism!"


 * According to a recent interview in 1UP Emil Pagliarulo denied any intentional relation between Liberty Prime and Optimus prime, it's a completly made up name, created long before the Transformers Movie made Optimus Prime a 'famous' name again. Though Emil also admits he could have made the reference subconsciously, as he sometimes is known to do.


 * It is possible to listen to him speak before he's fully on-line. At his feet in the Citadel lab there is a terminal and accessing this terminal allows you to run a voice test. It is best heard by adjusting the volume on your game, turning "Master" and "Voice" all the way up, then maybe even upping your TV or Computer's volume


 * The nukes he throws, despite being quite a bit larger than the Mini Nuke, have the same blast. This may be because Bethesda wanted to limit the amount of damage he could do to the player, or due to relatively antiquated technology compared to the mini-nukes.


 * When being removed from the Citadel basement via crane, if the player goes outside, he/she can see Liberty Prime's gargantuan leg colliding with the Citadel wall due to the inept guard operating the crane.


 * Liberty Prime is not the first giant robot that Bethesda Softworks has created as a major plot element: The brass golem Numidium has featured prominently in The Elder Scrolls II: Daggerfall, and its successor Akulakhan was also featured prominently in The Elder Scrolls III: Morrowind.


 * The American Soldiers in the Operation: Anchorage DLC also uses some of the quotes from Liberty Prime.

Bugs
It is possible that Liberty Prime will have path issues on the first large bridge you cross, and get "stuck" requiring you to reload a save. Sometimes these path issues can be resolved by destroying the junked cars on the bridge. also fast-traveling to the Citadel (only an option if you are out of combat) while prime is "stuck" and run back to the point where Liberty Prime is will help solve the problem. Also Liberty Prime will sometimes simply not move from his starting location. He wont even try. If he gets stuck behind a car simply blowing it up will work however there is a possibility an Enclave Vertibird will crash in his path in which case you can shoot whatever you want at it but it won't move unless you get out the MIRV. Sadly this makes all Brotherhood forces except Paladin Lyon hostile towards you.

Quotes
Liberty Prime has many quotes including:

Die mother FUCKER
 * "COMMUNISM IS A LIE."
 * "DEATH IS A PREFERABLE ALTERNATIVE TO COMMUNISM."
 * "COMMUNISM IS THE VERY DEFINITION OF FAILURE."
 * "CHAIRMAN CHENG WILL FAIL...CHINA WILL FALL!"
 * "VOICE MODULE ONLINE... AUDIO FUNCTIONALITY TEST... INITIALIZED. DESIGNATION: LIBERTY PRIME. MISSION: THE LIBERATION OF ANCHORAGE, ALASKA. PRIMARY TARGETS: ANY AND ALL RED CHINESE INVADERS. EMERGENCY COMMUNIST ACQUISITION DIRECTIVE: IMMEDIATE SELF-DESTRUCT.
 * "BETTER DEAD THAN RED!!"
 * "FREEDOM... IS THE SOVEREIGN RIGHT OF EVERY AMERICAN."
 * "EMBRACE DEMOCRACY, OR YOU WILL BE ERADICATED."
 * "DEMOCRACY IS NON-NEGOTIABLE."
 * "ENGAGING RED CHINESE AGGRESSORS."
 * "ANCHORAGE WILL BE LIBERATED."
 * "COMMENCING TACTICAL ASSESSMENT: RED CHINESE THREAT DETECTED."
 * "COMMUNISTS DETECTED ON AMERICAN SOIL. LETHAL FORCE ENGAGED."
 * "COMMUNISM IS A SMALL SETBACK... ON THE ROAD TO FREEDOM."
 * "OBSTRUCTION DETECTED. COMPOSITION: TITANIUM ALLOY SUPPLEMENTED BY PHOTONIC RESONANCE BARRIER. PROBABILITY OF MISSION HINDRANCE... ZERO PERCENT !!"
 * "INITIATING DIRECTIVE #7395: DESTROY ALL COMMUNISTS!"
 * "THE LAST DOMINO FALLS HERE. COMMUNISM... IS A LIE"
 * "A MINOR SETBACK ON THE ROAD TO FREEDOM."
 * "COMMUNISM... IS DEATH."