Written alongside producers Max Martin and Shellback, it was released on November 14, 2017, as the third single from her sixth studio album, Reputation.

Swift and Sheeran sang the song again in 2024 as part of a mashup with "Everything Has Changed" (2012) and "Thinking Out Loud" (2014) on the fourth night in London.

[2] For his songwriting, Sheeran came up with the inspiration while attending a Fourth of July party at Swift's residence in Rhode Island.

[15] Swift and Sheeran performed "End Game" for the first time during the Jingle Ball festival hosted by iHeartRadio on December 2, 2017.

[17] Swift performed "End Game" as an acoustic surprise song as part of her Eras Tour concert on November 11, 2023, in Buenos Aires,[18] and with Sheeran as a mashup with "Everything Has Changed" and "Thinking Out Loud" on August 15, 2024, in London.

Kitty Empire from The Observer selected "End Game" as an example for Swift's experimentation with R&B on Reputation, noting that it "isn't very good".

[20] In a review by Pitchfork, Meaghan Garvey was not impressed by the guest appearances of Future and Sheeran, the former of which was seemingly a means to help Swift stay relevant with contemporary hip hop trends.

"[4] Brian Josephs from Spin praised Future's verse, feeling that the rapper "fully owned it, making him a bizarrely good fit for a modern day Swift song".

[8] Writing for PopMatters, Evan Sawdey picked "End Game" as one of Reputation's "misguided" songs, alongside "Look What You Made Me Do" and "This Is Why We Can't Have Nice Things".

[22] Raise Bruner from Time considered the song to be Swift at her peak: "emotionally open, but ready and willing to have some fun with the hype around her own persona".

[23] Spencer Kornharber from The Atlantic called the song "maddeningly catchy" and compared its styles to music by Rihanna.

[24] Rob Sheffield from Rolling Stone was similarly positive, calling it "deeply weird, wildly funny", praising the chemistry of the three artists and Swift's witty lyrics.

[46] Directed by Joseph Kahn, the video depicts Swift partying at three locations during nighttime: with Future and partygoers on a yacht in Miami, with Sheeran at a nightclub in Tokyo, and with various friends on a double decker bus in London.

[50] Frank Guan from New York observed that the video effectively eschewed Swift's previously well-known girl next door image, by "drinking, playing a game on her mobile phone, hamming it up at a karaoke bar, cheerfully failing at Dance Dance Revolution, really getting into Future, having a crowd of friends with only a few white girls and no white guys [apart from Ed Sheeran] in sight".

Guan was impressed by the video's nighttime aesthetics featuring darkness against flashing lights and vivid colors, writing that "the end result is as simple as it is appealing".