The potential recruit is first subjected to testing, including tissue compatibility tests and psychological screening. Relatively few get past this initial selection process. Those that do pass are termed Neophytes, and the process continues with the surgery, indoctrination, conditioning, and training that will make them Space Marines. Those that survive but fail surgery or screening are either retained as or mechanically augmented and turned into semi-sentient to serve the Chapter, mainly under the command of Adeptus Mechanicus aligned Tech Marines of the Chapter who perform most tasks involving creation or maintenance of technology.