Overall, the "John Wick" films are difficult to categorize — they're an odd hybrid of noir, spaghetti westerns, crime thrillers, action movies, and several other genres that seem like they might not blend seamlessly. However, the franchise can actually be categorized within a very specific genre called "gun-fu," which can be traced back to the films of John Woo, among others.

Taking the balletic approach of classic kung-fu movies, including more modern iterations featuring actors like Jackie Chan and Bruce Lee, Woo introduced guns into the mix with films like "Hard Boiled," which, in particular, is famous for a three-minute fight scene regarded as one of the best ever shot. The Wachowskis were the next directors to employ "gun-fu," making gunfights an elegantly shot affair that elevated a typical action sequence; crucially, "The Matrix" used famed choreographer Yuen Woo-ping, who went on to help choreograph other homages to the kung-fu genre, including "Kill Bill." In 2002, the little-seen Christian Bale movie "Equilibrium" also served up intense action scenes with a side of gun-fu. "John Wick" is among a new group of films joining the genre, using the weapons as props in highly stylized sequences and creating stylized, optically gorgeous set pieces to please audiences.