Super Mutant

Super mutants are mutated humans, products of the Forced Evolutionary Virus, or F.E.V.. They are much taller and bulkier than humans, have (mostly) green, gray or yellowish skin, are immune to disease and radiation, and are gifted with superhuman strength and endurance. Although they are completely sterile, constant regeneration of their DNA caused by FEV makes them biologically immortal (but not impossible to kill, of course).

Biology
Average super mutants stand approximately 3.2 meters tall and weigh around 360 kg. Their skin color is predominately gray with tints of green, although some mutants with other skin colors also exist. Their skin is extremely tough, and their muscle and bone structure is enhanced.

Super mutant cells undergo cellular division at an increased rate. Mitosis occurs at a rate 15% quicker than that of normal humans. Cellular structure is to be highly similar to normal humans. DNA strands are very complete, with all recessive genes for ailments eradicated from the system. The recessive genes which are commonly found in humans have been manipulated in such a way as to bring about the best possible combination. The RNA were also manipulated to allow for a greater transmission of signals.

The mutation has some severe side effects. Chief among them is sterility. As the gametes of the reproductive system consist of 'half-cells' using split DNA, they are perceived as 'damage' by FEV, which repairs them, rendering the mutants sterile. Super mutants are unable to reproduce with any creature, whether clean or mutated. Other side effects include an alteration of pigment of the epidermis.

While they don't die of old age, they do get senile with age, which also makes them more prone to being killed.

Master's Army
Super mutants were created by Richard Grey, also known as "The Master", who led the expedition to Mariposa Military Base in 2102. When the expedition was attacked by robots, he was himself dipped in a FEV vat, and managed to crawl out. FEV was initially meant to be injected into humans, but Grey soon found out that direct physical contact worked as well. He began to mutate in horrible ways, turning into a blob of flesh-like material. He developed psychic powers, which were enhanced by consuming living minds to expand his own brainpower. Slowly, as wanderers made it into the base themselves, he started doing his own experiments with FEV. Grey--who now called himself the Master--lamented the needless destruction of the Great War. In his warped state, he decided that he would have to force humanity to evolve. If everyone could be as perfect as his super mutants, there would be no more conflict. Those who could not evolve would die. Around 2155, the Master began seeking out uncontaminated humans with which to create mutants and build his super mutant army.

However, creating super mutants was a very hit or miss process. The great majority of super mutants produced by the Master and later his Lieutenant in Mariposa's Vats were big, dumb brutes. Physically, they were vastly superior to humans, but they had the intelligence of children. What exactly causes some mutants to be brilliant and others to be stupid is unknown. The Master was certain it was related to radiation damage: humans who hadn't been exposed to too much radiation yielded smarter mutants (see his personal diary for his thoughts on this). His Lieutenant, however, had a different theory. When the bombs hit the research facility and turned it into the Glow, they cracked open a few tanks filled with FEV. The bombs' radiation then mutated this FEV into an airborne strain. But this new airborne FEV didn't have any real mutagenic effects on people. All it did was inoculate human subjects against the real FEV, acting as a sort of vaccine. The ideal dipping subject was someone who hadn't been exposed to the airborne FEV. Both of these conditions--no radiation exposure and no mutant FEV inoculation--were present in one population: Vault dwellers. Each Vault contained around 1,000 viable subjects to be dipped and turned into super mutants. Which factor exactly determines what you'll get from a dipping--radiation or inoculation--is still uncertain, though as a rule of thumb, the cleaner the subject, the better.

Fall of the Master
In 2162, a man known as the Vault Dweller destroyed the mutant army by causing an explosion in the FEV vats at Mariposa, which collapsed the entire base, and killed the Master. Without the leadership of their creator and his lieutenant, the mutants divided into at least three factions. One of them decided to leave California and find a place for themselves somewhere in the East. Another wanted to continue the Master's work, rebuild the army, and dominate the Core Region once again.

Some super mutants, however, especially those who retained more of their intelligence than their less pure brethren, wanted to make peace with humans, put old differences aside and work together to rebuild the world after the War. In 2185, super mutant Marcus and Brotherhood of Steel Paladin Jacob crossed paths in the desert and punched and shot at each other for a few days. Eventually, they gave up, unable to get an advantage over the other. The two started traveling together, arguing over Master and BOS doctrine. Eventually the two, along with the trail of ghouls, humans, and super mutants, founded the community of Broken Hills. Some super mutants also settled in other more tolerant human communities, like the New California Republic.

Gammorin's Forces
Some time after their departure, the faction led East by Gammorin was pursued by Brotherhood of Steel airships. While most of them ended up in the vincinity of Chicago, far from Gammorin's forces, one of the zeppelins crashed north of the mutant encampment. The leader, Paladin Latham, challenged Gammorin to a single unarmed combat and, to surprise of everyone, killed the mighty mutant. As he defeated the previous chieftain, the super mutants expected him to become the new leader of their army. Latham suffered a head injury during the combat, and throughout the years, he grew more and more insane, even though he managed to organize the mutant forces into an army nearly as powerful as they had been during the Master's reign.

When Latham's forces encountered Calculator's robots from Vault 0, he swore an oath to destroy the cybernetic menace. By that time, he assumed the name "Gammorin", after the mutant chief he had killed. Gammorin's mutant scientists ran extensive research in order to find a cure to super mutant sterility. However, their laboratories in Jefferson City were destroyed by a splinter faction of the Brotherhood of Steel from the Chicago area, who believed it to be a weapons manufacturing plant. Eventually, Latham/Gammorin and his forces were defeated by the Brotherhood. After the defeat, many mutants were, however, allowed to join this Brotherhood to fight against the robots. The Brotherhood tried to continue the work on the cure to super mutant sterility, but they were unsuccesful.

Forces of Attis
A smaller sub-section of the mutant army did remain together in the Core Region, under the command of a visionary lieutenant named Attis. Highly intelligent and vindictive towards the Brotherhood of Steel, Attis took his group into hiding, searching for clues regarding the history of the FEV virus. Some time after 2208, learning about a secret Vault-Tec installation in Texas with new and possibly improved versions of the FEV virus, Attis led his group to the area where the rumors started, the ruined city of Los. His ultimate goal was the continuation of The Master's plan - to rebuild the mutant vats and eventually transform the entire human race into mutants. His forces were eventually defeated by the Brotherhood of Steel.

Second Generation
In 2236, the Enclave discovered the remnants of the Mariposa Base. Soon, assault squads combed the desert for slaves they could use to mine the military base and get to the Vats. One of the squads included soldier Frank Horrigan. Enclave construction crews, as well as human and super mutant slaves began excavations. In September they uncovered FEV, and mutations began to occur in the human workers. Frank Horrigan comes into contact with the virus and is sent to the Enclave labs for study.

In 2237, having obtained the FEV data, the Enclave abandoned the site after more mutations occured, causing 2nd Generation super mutants to arise - the Enclave left a single squad behind to wipe out the super mutants, but the mutants, using armaments they have cached in the base during excavation, reduced the squad to ashes after suffering heavy casualties. The remaining 1st and 2nd Generation super mutant slaves were sealed inside the base by Enclave sappers, who collapsed the entrance to the base. The mutants formed a new community under the leadership of Melchior, whose magician talents had allowed them to hide the weapons.

East Coast
By 2277, the Super Mutants have appeared on the East Coast of the United States. These Super Mutants were created in the Evolutionary Experimentation Program, the experiment assigned to Vault 87. The modified strain of FEV which created these mutants resulted in a new strain of Super Mutants which, in addition to becoming senile, grow larger and stronger as they age. They are different as they are yellow in skin and less intelligent outside of combat they take prisoners to make more of them.

During exploration of Vault 87, information from a terminal reveals more about the process of mutation that Super Mutants go through, at least when it comes to the specific strain of FEV found in the Super Mutants found in the Capital Wasteland. As a human mutates, it's muscular and skeletal systems develop rapidly, while their mental faculties diminish. Also, sexual characteristics are eliminated: reproductive organs disappear, and they develop uniformly, without secondary sexual characteristics. A female human exposed to this strain of FEV would develop exactly the same as a male, thus it's impossible to differentiate between Super Mutants born female and those born male.

In Fallout 3, Super Mutants are divided into different classes, each more powerful than the previous. This is likely done to more easily fit into the game's dynamic leveling system, ensuring that the PC always encounters enemies of reasonable difficulty. These classifications, in order of weakest to strongest, are "Super Mutant", "Super Mutant Brute", and "Super Mutant Master". Note that the Super Mutant Behemoth is not included in this list as these are special, unique encounters rather than generated opponents.

Appearances in games
Super mutants appear in all Fallout games.

Inconsistencies
In the first two fallout games it was stated, that FEV increased size and musculature by about 30%. This would give only 2.5m average height.

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Supermutant