For the phonebook scene, a prop was made out of foam and rubber, so Keanu Reeves could genuinely hit Grill, played by The Game. Initially, Game insisted on using a real phonebook, but after only one take, he asked to switch back to the fake prop.
The film was shot in a grueling 43 days with very long hours for the cast and crew, according to director David Ayer.
The chase sequence in South Central really took place in alleys and back of people's houses which took over two nights.
Detective Tom Ludlow (Keanu Reeves) wakes up at the beginning to the same alarm sound as in Matrix (1999), where he played Thomas Anderson a.k.a. Neo.