The premise of the show involves eight female K-pop rappers competing against each other to showcase their vocal abilities.

Second World was a singing competition featuring head-to-head battles, unit performances, original re-arrangements of well-known songs and collaborations with various producers.

The show's concept revolved around the aim of showcasing the vocal abilities of rappers in K-pop groups, who are often misconceived as not being strong singers.

Furthermore, the show allowed them to showcase their diverse musicality which may not have often been possible when limited to their role as rappers in their respective groups.

Global Hearer scores are based on a maximum of 300 points, wherein the contestant with the highest number of preliminary votes receiving 300 points, and the scores of the rest of contestants shall be based in proportion with the highest votes.