There's only one movie you need to watch for Avengers: Endgame 1 / 8
MCU crossovers can rely strongly on previous films. 2 / 8
But a complete rewatch means watching over 20 movies. 3 / 8
If you want to understand Avengers: Endgame, Avengers: Infinity War is the only one you have to watch. 4 / 8
Some of the films, like Captain America: Civil War, do help with character arcs. 5 / 8
The Guardians of the Galaxy movies flesh out Thanos as a villain and introduce cosmic Marvel. 6 / 8
Thor: Ragnarok explains where Thor and Hulk start in Infinity War. 7 / 8
But if you only have time for one, Avengers: Infinity War is absolutely it. 8 / 8