<p>The “sergeants-and-soldiers” effect is a significant feature of helical copolymers, where a small fraction of chiral components can endow the copolymers with an intense optical activity close to that of chiral homopolymer. With the development of helical polymers, some abnormal examples have also been discovered, in which the twisting sense of main chain can be inversed with the increment of chiral unit content, termed as abnormal “sergeants-and-soldiers” effect. In this review, we detailedly summarize the development of “sergeants-and-soldiers” effect and its theoretical model in chiral polymer systems, including normal and abnormal “sergeants-and-soldiers” effects, modification of Ising model, dynamic transformation of the above two chiral amplification effects, as well as their applications in chiral separation, asymmetric catalysis, and circularly polarized luminescence. Finally, the remaining challenges are discussed to provide an outlook on the future directions.</p>