Show No Mercy is the debut album by American thrash metal band Slayer, released in December 1983 through Metal Blade Records. Brian Slagel signed the band to Metal Blade after watching the band perform the song "Phantom of the Opera" by Iron Maiden. The band was forced to self-finance their debut album, combining the savings of vocalist Tom Araya, who was employed as a respiratory therapist, and money borrowed from guitarist Kerry King's father.
Touring extensively promoting the album, the band brought close friends and family members along the trip, who helped backstage with lighting and sound. Although criticized for poor production quality, it became Metal Blade Records highest selling release, also producing the songs "Die by the Sword", "The Antichrist" and "Black Magic", which are played at Slayer's live shows regularly.
The band used Satanic themes in both lyrics, and live performances to gain notice among the metal community. The back cover featured 'side 666'? and inverted crosses, with Hanneman playing his guitar. Due to the imagery and lyrical content Slagel received mail from the PMRC telling the band to stop releasing records; Araya comments "Back then you had that PMRC, who literally took everything to heart. When in actuality you're trying to create an image. You're trying to scare people on purpose." The album produced the songs "The Antichrist," "Die by the Sword," and "Black Magic", which are played at Slayer's live shows regularly.