PG-13 Didn’t Exist Before Gremlins
The summer of 1984 was an important one for film ratings. Along with Gremlins, Indiana Jones and the Temple of Doom came out. Both films were in the top five highest grossing movies of the year, and both were rated PG.
Because both were dark and violent, Steven Spielberg suggested the MPAA create a new rating to accommodate them. By creating the PG-13 rating, studios were able to release darker more violent films without the audience limiting R rating. The first film to get a PG-13 rating was Red Dawn.