Hardcore Rap (also referred to as Hardcore Hip-Hop), is a form of hip hop music that developed through the East Coast hip hop scene in the late 1980s. Pioneered by such artists as Kool G Rap and KRS-One, it is generally characterized by an aggressive sound and confrontational lyricism, while the form has often been associated with gangsta rap. Following a breakthrough in the early 1990s, hardcore hip hop became a popular crossover style during the mid-1990s. Hardcore Rap reflective lyrical themes include partying, braggadocio, crime, violence, sex, nudity, wrath, poverty, menacing, omen, rebellion, profanity, racism, drugs, weapons, resentment, ghettos, gangs, social issues, consciousness, struggling, nihilism, distrusting, life, death, police brutality, and the harsh experiences of the rapper's urban surroundings. Run-D.M.C. have been credited as the first hardcore hip hop group. Before a formula for gangsta rap had developed, artists such as Boogie Down Productions and Ice-T wrote lyrics based on detailed observations of "street life", while the chaotic, rough style of Public Enemy's records set new standards for hip hop production. In the early 1990s, hardcore rap became largely synonymous with West Coast gangsta rap, as exemplified by N.W.A, until the Wu-Tang Clan emerged in 1993. Wu Tang Clan's minimalistic beats and piano-driven sampling became widely popular among other hip hop artists of the time, such as Onyx, House Of Pain, Ras Kass and Cypress Hill. The most notable Southern hardcore scene existed during the 1990s in Memphis, where the dark, gritty lyrics and production (labeled by some as Horrorcore) contrasted with more party-oriented Southern hip hop.
Gangsta rap has been associated with the style; however, not all hardcore hip hop revolve around "gangsta" lyrical themes, even though there is a great deal of overlap, especially among hardcore rappers of the 1990s. Allmusic stated that hardcore hip hop is characterized by "anger, aggression and confrontation whether in the lyrical subject matter, the hard, driving beats, the noisy sampling and production, or any combination thereof." Russell Potter wrote that while hardcore rap has been associated with a "monolithic 'gangsta' outlook" by the popular press, hardcore rappers have "laid claim to a wide variety of ground". .