Mutations and their causes

Radiation


The various types of mutant creatures that inhabit the wastelands were mostly created by radiation. This is where mantises, geckos, spore plants, radscorpions, brahmin and the various mutant rodent species originated from. Radiation is also how ghouls - decrepit, ragged, almost rotting, zombie-like victims of massive radiation poisoning - are made. Many ghouls were created from vault dwellers living in Vault 12 under the city of Bakersfield (better known as the Necropolis after the War). As part of the vast Vault Experiment Program, the Vault 12 vault door was designed not to close properly. Thus those within the vault were exposed to massive amounts of radiation, the majority of which became ghouls.

Many question these facts, suggesting that radiation doesn't create giant scorpions and zombies. However, in the Fallout universe, things are different. In accordance with 1950's sci-fi physics, radiation makes things bigger and meaner, though under most circumstances, creatures, including the player, can still suffer radiation poisoning and radiation in this case is a fatal thing.

Forced Evolutionary Virus


The other source of mutations in the Fallout world is FEV: the Forced Evolutionary Virus. The super mutants, floaters, centaurs and possibly wanamingos were products of FEV infection. Harold was also mutated by FEV, even though he looks like a ghoul.

It was initially called the Pan-Immunity Virion Project and was created to fight a disease called the New Plague. However, abnormal side effects were observed in test subjects. The test animals began to grow dramatically and their brain activity increased. Seeing the potential there, the Army sent its own people to secure the project and renamed it FEV: Forced Evolutionary Virus, which would turn soldiers into abnormally strong and intelligent supermen.

The Military Base where the FEV was stored was discovered by a group of explorers including Harold and Doctor Richard Grey. Most of whom died when they encountered the automated defense systems. Soon, only Grey and Harold remained. Harold was knocked out (he never did find out how) and woke up out in the desert looking like a ghoul. Grey was knocked into a vat full of FEV by a crane and managed to crawl out. He began to mutate in horrible ways, turning into a sort of blobby kind of thing. He developed psychic powers, which were enhanced by consuming living minds to expand his own brainpower. Slowly, he started doing his own experiments with FEV.

Grey found that many of the test subjects were metamorphosing into giant, mindless brutes with the brains of a child, if they survived at all. However, a rare few test subjects yielded super mutants. Immune to disease and radiation and blessed with exceptional strength, intelligence and endurance, super mutants were superior to humans in every way. They also possessed the exceptionally long life of the mutated as well as the total sterility. Grey--who now called himself the Master--lamented the needless destruction of the war. He decided that he would have to force humanity to evolve. Those who could not evolve would die.

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, there 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. As a rule of thumb, the cleaner the subject's DNA, the better.

Aside from super mutants, the Master also created a variety of other creatures. No one is sure where the floaters came from, but then again most would rather not know. Centaurs were created by tossing a varied mix of dogs, cats, brahmin and other animals into a vat and seeing what came out the other end.

Other Mutants


There are a few other types of mutant creatures in the wasteland that don't directly stem from FEV or radiation. These are mostly the intelligent animals and one spore plant encountered in Fallout 2. The intelligent spore plant and radscorpion in Broken Hills were another, separate experiment conducted by a scientist there. The alien creatures encountered in Fallout 2, which were a pre-war experiment conducted by the US military similar to the Enclave's intelligent deathclaw research, were all, without exception, killed by the protagonist in Fallout 2. Occasionally, other intelligent animals have appeared here and there in the Fallout games, but all have been flukes. A race of intelligent raccoons living in an colony known as the Burrows was originally intended to appear in Fallout 1, but was cut due to style issues.

Frank Horrigan, Enclave super toughie, was produced by a series of treatments involving carefully modified FEV, surgery, a variety of other drugs and a great big suit of armor. He's dead, too. Lastly, Harold, who looks a lot like a ghoul, but he really isn't. Ghouls are the result of massive radiation exposure while Harold was mutated by brief FEV exposure without being dipped. FEV is at best unpredictable and you never can tell what'll come back out of the vats (just look at the Master). Harold is essentially a fluke, the result of a unique combination of a specific degree of exposure to the virus, a specific degree of radiation within his own body and any number of other factors. While FEV doesn't crank out ghouls as reliably as it does super mutants, it does occasionally spit out something that looks like one: Harold.

Another important exception is Talius, the ghoul-like creature that was hiding with the Followers of the Apocalypse and who was turned into his current state by FEV exposure, much like Harold though under different circumstances.

Variants
Over the years, different people have been in charge of Fallout canon and have come up with different interpretations on this subject. Mutant creatures and where they come from is one of the most controversial topics in Fallout canon and it's very easy to annoy veteran scholars of the setting by getting things wrong or even just partially right.

First, Chris Avellone seemed to prefer the "FEV explains everything!" theory of mutation. He suggests that when the Glow was hit by the Chinese warheads, the tanks holding the virus burst and the FEV was vaporized and shot into the air. It was then mutated by the radiation from the blast, and went on to help radiation create the various mutant animals we know and love as well as ghouls. The problem with this theory is that first off it's a bit redundant since Fallout radiation is already fully capable of producing the mutations seen in the gameworld. Second, we know from the Lieutenant's mention of inoculation from mutant FEV that any airborne strain of FEV could not cause these mutations. If it did, why didn't any humans mutate from exposure to the airborne FEV? Furthermore, if radscorpions, geckoes, molerats, deathclaws and other creepie crawlies are all products of FEV, how can they breed as much as they do? Remember, FEV causes sterility. Avellone eventually admitted that he was wrong, and that most mutations in the Fallout world were caused by radiation.

Next, Chris Taylor offers a different point of view on how ghouls are made. He suggests that when people with too much radiation damage are dipped, you get ghouls. When people with mild radiation damage are dipped, you get stupid supermutants. When people with very little radiation damage are dipped, you get intelligent supermutants. This would mean Harold is a normal ghoul. However, since the population of Vault 12 was never dipped, not all ghouls could be made this way, only that FEV would speed up the process slightly.

Harold is also knowen to be the name (or the exact same ghoul told about above) of a ghoul witch ended up havig a tree attached to his head trough slight mutation, he appears in Fallout and Fallout 3, while in Fallout 3 the tree appears to have "absorbed" Harold, and also appears to be Harold himself now.

Enclave Mutation Policy
The Enclave holds the view that any "human" who has been "exposed" to radiation is a mutant and all mutants should be destroyed. The Enclave's definition of "exposure" would seem to mean that only Enclave members and people still residing in Vaults count as human beings.

Related Holodisks

 * Alpha Experiment Disk
 * Delta Experiment Disk
 * FEV Experiment Disk
 * FEV Research
 * Richard Grey Audio Diary
 * Vree's Experiment Disk
 * Captain Maxson's Diary