Introduced by African American communities, Chinese rap battle features an intensive ritual exchange of impoliteness, aggression, and vulgarity, but its linguistic realizations have not been systematically examined. Taking Iron Mic as a case study, this paper explores how advanced and novice rappers perform ritual impoliteness in Chinese underground rap battle competitions. Using mixed methods of discourse analysis and content analysis, we analyze the ritual impoliteness strategies in 51 rounds of Chinese freestyle rap battles. The findings show that advanced and novice rappers employed comparable instances of taboo language, threatening, and insults on their opponents’ superficial qualities and rap skills. Moreover, advanced rappers performed significantly more boasting and ritual insults on the others’ moral qualities. Their use of ritual impoliteness is warranted by hip-hop community norms of authenticity and creativity as well as Chinese social values of reciprocity, filial piety, and moral educators. This paper contributes to the research on Chinese ritual impoliteness and rap battle competitions.