Only one criterion : genetic perfection
Why it is hard sci-fi
A society in which embryo selection has been industrialised. Job placement, insurance, and life prospects are decided by genetic profile at birth. The film follows a man with an unselected genome who passes as a selected client by buying biological samples from a paralysed donor. The procedural detail is exact. Hair, skin flakes, urine samples, and contact lenses are all part of the deception, and the lab assays are explicit.
Science inside it
Pre-implantation genetic diagnosis, polygenic scoring, statistical prediction of disease and lifespan, identity verification through genotyping. The film also asks an honest question about what selection does to the unselected, treating discrimination as the inevitable consequence of a working test rather than a bug.