A very simplistic explanation is that gammas are like betas, but with much greater resistance to mutation. In this universe, betas can be mutated into omegas or alphas if exposed to certain pheromones of dominant alphas/omegas without much difficulty. Gammas, on the other hand, are extremely resistant to mutation. It's not impossible to mutate them, but very, very difficult.
thank you all for the explanation cuz i don't really wana read their story bcause of the spoilers i read about them. i read a lot of tragic and toxic sht ending but i think i won't like one bit of eat me if you can novel. but i becme curios about miller family and the worldbuilding after reading desire. especially stacy and lauren since stacy had the same defect as greyson and lauren after that hospital scene and bcause she's also a wanted fraudster lol.

ive seen a spoiler that miller's grandpa is a gamma that was forcibly turned into an omega by his alpha partner. so what's a gamma? how are they different from alpha beta and omega?