Reign in Blood is the third studio album and major label debut by American thrash metal band Slayer. It was released on October 7, 1986 on Def Jam Recordings. The album was the band's first collaboration with record producer Rick Rubin, whose input helped the band's sound evolve. Reign in Blood was well received by both critics and fans, and was responsible for bringing Slayer to the attention of a mainstream metal audience. Kerrang! magazine described the record as "the heaviest album of all".