Here's a treatment of a Gamma World campaign setting I never got to use (BTW, this write-up is from the late 90s (note the WW-style 'glossary') - so, no 'Change' was not picked as a political commentary.):
Gamma World setting.
Universe City was preserved from the ravages of Change sometime after the end of the 20th century, sealed beneath of dome of durralloy and provided with an artificial sun, while the world Changed around it. Then, the Black Years came and world outside Changed a final time. The Bomb was dropped, civilization was destroyed in an atomic apocalypse and nuclear winter, just as had been feared, even in the 20th century. But, Universe City survived, carrying with it all the knowledge of the 20th century, preserved and protected forever by the noble Curators.
In Universe City, only Period knowledge is preserved in writing. Post-Period history is carried on as oral traditions, both among Curators, and common Citizens and Visitors. Thus, it can be quite varied. In general, it is believed that it has been many generations since the Bomb, but that the traditions of Universe City have 'always' been the same. Many versions of non-Period history claim that there was a period of strife immediately after The Bomb, when the Curators held or siezed power, and other factions were eliminated. Some illegal movements, such as The Right and The Staff claim to be the heirs of these factions, and rightful rulers of Universe City.
Since Period science is taken as absolute truth, mutations are believed to be invariably negative - the obvious evidence of human and animal mutant Visitors not withstanding.
Today, Visitors are becoming more and more common, and 'Eclipses' longer and more frequent.
Bomb, The - The descrution of the rest of the world in a nuclear holocaust brought on by the forces of Change.
Change - 'Change' is what destroyed the world. It is a word that in synonymous with death, but also with the powers of post-20th century technology. It is a word that evokes dread, fear, horror and wonder. Though it is used in the oral tradition of the Curators and others, it is primarily uttered as a curse.
Changers - The boodgeymen of the Citizens, Changers are said to apear human, but to alter thier form, as well as being the pawns of the forces of Change which destroyed the rest of the world. Visitors are often suspected of being Changers, and killed as a result.
Citizens - Persons born or 'naturalized' in Universe City, who are not Curators or Students. Citizens are gauranteed many rights and freedoms, in accord with Period ideals of democracy, humanity, and the rule of law - such as the right to vote for which of the Curators presides over the city, and the freedom to Emmigrate if they do not wish to obey the Curators.
Constellations, The - Dim patterns that appear on the sky when the Sun is not shining. They have the traditional names and meanings (preserved in Period astrology texts), but being born 'under' a constellation is a bit more litteral in Universe City.
Curators, The - The qualified leaders of Universe City, educated in the Period ways generation by generation back to the original Preservationists. All Curators must be Pure Strain Humans (as induced mutations, according to Period science, can only result in genetic deficiency) and Students must complete a long, diverse and rigorous curriculum to join thier ranks.
Degree - Rank among the Curators. Curators of the lowest degree are not allowed to marry. Those of the highest degree may be democratically elected to preside over Universe City.
Democracy - Rule by the people. The ideal form of Period government, preserved in Universe City through the benevolent guidance and instruction of the Curators.
Drop-Outs - Failed Students, especially those who dare to oppose the Curators. The Curators often consider them a threat, and the common Citizens are suspicious of the secrets they may know.
Eclipse - A period of Darkness that occurs when the sun is supposed to be shinning.
Education - Training taken from the Period books, tapes, and compact optical storage disks preverved in Universe City. All Citizens are expected to avail themselves of their right to a good Education.
Emmigration - Exile from Universe City. Tantamount to death.
Experience - Knowledge acquired from non-Period sources. This includes both the oral traditions of the Curators, and any information gleaned from Visitors.
Immigrants - Proper Period term for 'Vistitors.'
Military Service - When neccesary, Citizens are armed with Period weapons and sent Outside to take action against dangerous Changers who may threaten Universe City from without. Few return. Those that do are often either mutated or just don't live long. For this reason, as well as Period peace activism, war is very unpopular among the Citizens, who are usually willing to make any required sacrifices to avoid it.
Outside - The rest of the world, or earth, that was destroyed by the Bomb. A radioactive wasteland. Also, metaphorically, a hellish afterlife.
Peacemaker - Sidearm carried by the UCPD. Shaped like a mid-20th-century police revolver, but actually a six-shot stun ray pistol.
Period - Anything of the 20th century - knowledge, language, culture, literature, and artifacts. Since earth survived the 20th century in pretty good shape, all things that are Period are good. All things that are not Period are bad - either dangerous harbingers of Change or pathetic decline to the Primitive.
Preservationists, The - The first Curators, and thier outside supporters, who saved Universe City from Change. Revered with something like religious awe.
Primitive - Anything that would have been recognized in the 20th century as being of the past. Swords, belief in magic, animal-drawn transportation, etc. Primitive things and people are to be politely derided and pittied, rather than feared.
Right, The - An outlawed movement among the Citizens, based on forbidden Period knowledge purported to allow the superstition of belief in a higher being, the acquisition of wealth and power by individual Citizens, and the execution of those who are not Right.
"Speedies" - Officers of the UCPD.
Staff, The - Illegal movement among the Citizens, claiming to have knowledge of the technology of Change, and to be the rightful rulers of Universe City. Officially, they are said to be servants of the Curators who revolted and were rightfully Emmigrated. A key legend among them refers to a Staff that can control the Sun.
Students - Citizens accepted by the Curators into a comprehensive program of Education and indoctrination, which leads to the best of them becoming Curators, themselves.
Sun, The - An artificial source of light and heat that daily traverses the sky. The Sun is assumed to function by nuclear fusion, like the unimaginably larger and more distant star, Sol, which naturally performed the same function for the rest of the earth.
Superstition - Belief in anything outside the realm of 20th century science, history, philosophy and general knowledge. Belief in gods or magic, post-20th-century science/history/knowledge, 'Ancients,' 'Mutant Powers,' etc...
Hurish - An outlawed religion, secretly practiced by many Citizens, which purports to believe that the whole of the outside world was not destroyed, and that rescurers from Outside will someday free them from bondage under the Curators, and lead them to a distant paradise, built and perfected by the forces of Change. For many years the Hurish were merely segregated and oppressed, then, at some point, they were actually outlawed and either 'converted' or Emmigrated. Also, some Hurish claim to also be a race apart, while for most it is merely a set of beliefs.
Universe City - A living re-creation of the Period (20th century), protected from Change by a durralloy sky (dome), and the efforts of the Preservationists (an SCA-like organization of the Ancients). So called, because it contains the complete 'universe' of knowledge available to the Period in a single settlement ('city').
UCPD - The Universe City Police Department. Chosen from among the Citizens by the Curators to keep the peace, UCPD officers wear classic mid-20th century police uniforms. The primary duty of the UCPD is to prevent citizens from harming eachother. Of course, since any activity that would threaten the Period order of the Curators would bring great harm to all Citizens, preventing and punishing such activities takes up most of thier time.
Visitors - Persons from Outside, mostly radiation-resistant mutants, who have immigrated to Universe City. They are poor, benighted beings, riddled with Primitive Superstion and bearing dangerous fragmentary non-Period knowledge and technology of Change. Also called Immigrants.
Wrong, The - An outlawed movement among the Citizens, based on forbidden Period knowledge purported to allow unlimmitted reproductive activity, unfettered equality of access to all resources, and the perpetual imprisonment of those who are not Wrong.
"You See" - A pun on the initials of Universe City, used to preface a statement that is meant to be taken as true.
In addition, most of the common terms in Gamma World - Ancients, Tombs, Artifacts, Domars, etc - are known to the inhabitants of Universe City, via the Visitors. Generally, though, they are taken as mere Superstition. Still a Citizen will not be completely at a loss when confronted with them.