Between 1934 and 1968, almost every Hollywood movie had to follow the 'Hays Code,' a set of moral guidelines that strictly prohibited what could be shown on screen. The code was created to avoid government censorship by proving the industry could 'police itself.' Under the code, criminals could never win, 'suggestive' dancing was banned, and even married couples had to be shown sleeping in separate twin beds. One of the most famous rules was the 'three-second rule' for kissing. Filmmakers became experts at using symbolism to bypass the code—such as showing a train entering a tunnel or fireworks exploding to represent intimacy. The code finally collapsed in the late 60s as filmmakers demanded more realism, leading to the birth of the MPAA rating system we use today.