As with the rest of Pure Heroine, "Glory and Gore" was written by Lorde and Joel Little, recorded at Golden Age Studios and produced, mixed and engineered by Little. "Glory and Gore" is a chillwave and hip hop-influenced electropop ballad, instrumented by pulsing synthesisers. According to the sheet music published at Musicnotes.com by EMI Music Publishing, it is set in a moderate tempo of 72 beats per minute. It is written in the key of F minor, and follows the chord progression A♭–Fm–Cm–B♭m. Lorde's vocals range from E♭3 to E♭5. Lyrically, it describes the glamorization of violence in the media.
In a review of Pure Heroine, Larry Day from The 405 called the track "single-worthy". Billboard's Jason Lipshutz called Lorde's vocals during the song's hook "contagious". Jon Hadusek of Consequence of Sound wrote that "Glory and Gore" did not fit in with the minimal production found in the majority of Pure Heroine. Pitchfork's Lindsay Zoladz criticised the song for having too many lyrics forced into each line. John Murphy from musicOMH was critical of the latter half of Pure Heroine, writing "by the time 'Glory and Gore' and 'Still Sane' roll around, the template's starting to sound a bit tired."
"Glory and Gore" was sent to United States modern rock radio by Lava Records and Republic Records on 11 March 2014 as the fourth US single from Pure Heroine. A US adult album alternative (AAA) release followed on 7 April 2014. "Glory and Gore" serves as the fifth single overall from Pure Heroine, as "Tennis Court" was released outside the US in 2013. Following the release of Pure Heroine, "Glory and Gore" appeared at number seventeen on the New Zealand Artists Singles Chart dated 7 October 2013. Prior to its single release, the song entered the United States Billboard Hot 100 chart at number 88 on the week of 8 March 2014, with sales of about 32,000 copies that week—almost double the sales of the previous week. The following week "Glory and Gore" sold 47,000 copies (up 46%) and became the Hot 100's "Digital Gainer" as it moved up to number 68 on the chart.The song peaked at number 30 on the US Digital Songs chart, number seventeen on the US Alternative Songs, and number nine on the main Hot Rock Songs. As of April 2014, "Glory and Gore" has sold 307,000 digital downloads in the US.
On 24 September 2013, Lorde performed the track, among others, at The Fonda Theatre in Los Angeles, California. On 3 October 2013, Lorde held a concert at the Warsaw Venue in Brooklyn and performed the song among other tracks from the album. Lorde performed "Glory and Gore" at Silo Park, Auckland on 29 January 2014 as part of her make-up show for the 2014 Laneway Festival, with The New Zealand Herald's Chris Schulz calling the performance a "highlight"