Synth

Synth is a diminutive for synthetic humanoid and is used to name synthetic intelligence units designed by the Institute to look, function, and behave like humans.

History
Pre-War, the Institute was contracted by the American government to develop artificial intelligence for military purpose. Working with Vault-Tec, the Institute developed parts of the ZAX supercomputers. The Great War forced the Institute below ground into the massive tunnel systems below the college. There, they were forced to devote less time to experiments and more time towards creating a viable below ground society.

Eventually, the situation below ground stabilized, with the Director and his Board keeping control of the Institute. Unfortunately, their models on the situation above ground turned out to be correct: livable, but there were still massive storms of radiation, raiders, and mutants. Missions to head to the surface for supplies were unpopular, resulting in the Institute trying to develop ways to purify the wastes.

Instead, a new purpose was found: purifying the body rather than the environment. The concept of the synth began here; a body, perfectly designed. Immune to radiation, mutation, disease, and aging. Literally, Mankind Redefined. It was hoped that eventually, the minds of those pure humans in the Institute could be transferred into the new bodies, and from there, they could reclaim the surface world as the perfect world, ushering in a new age of homo sapiens.

As generations of synths were developed, the Institute came closer. The earlier generations, once obsolete, were instead used for the above ground missions. The AI research was rediscovered and installed in the synths so they could complete their missions without needing active control from below ground. Eventually, new programs emerged that combined the AI and Mankind Redefined projects. This culminated in the Gen 3 synths, that were essentially indistinguishable from humans physically and mentally. The mental aspect was important, because this wasn't the original point of the Redefined project.

The mind transfer project would take time, so the Gen 3 synths were deployed in labor projects below ground and normal missions above ground. Settlers were kidnapped from the surface world to use in experiments to test whether their consciousnesses could be transferred into blank Gen 3 synths. Institute scientists found out, through the deaths of hundreds of test subjects, that the mind of the settler could be recreated in the synth, but not necessarily transferred.

Middleton
The research on mind transfer was primarily done at the Middleton Facility, a side lab located away from the main Institute, so it was spared during the destruction of the Institute by the Minutemen. Above ground was destroyed in the Great War, while the below ground was unknown to the Commonwealth and believed to have been destroyed in an accident by the Institute. However, a single synth survived. Calling himself Adam, he made it his life's work to install synths as the dominant race above ground.

He fixed the facilities in the below ground labs, and began creating a synth army to support him. However, one fundamental problem remained, one the Institute believed wouldn't be a problem should aging be fixed: synth reproduction. Eventually, the materials to make new synths would run out, and from there, since aging was never fixed, eventually the synths too would die out, a similar problem to the Master's Super Mutant army. Adam had his top scientists work on fixing these issues, while he had other synths establish a town above ground. Known as Middleton, it offered safe harbor to all synths displaced by the destruction of the Institute. Only synths, and only synths that hadn't been in contact with "human supremacist" organizations like the Minutemen or Railroad. Eventually, a large town was established, known informally as "Synth City" to the other towns in the Commonwealth. Adam and his top supporters ran the whole thing behind the scenes below ground. Above ground, a synth religion was created, dedicated to a being called "the Creator" which Adam planned to introduce himself as.