Being an actor isn't all about glamour and glory. There are a lot of long hours that go into making every movie, requiring the actors to perform one scene dozens of times to ensure that the director can get the best possible performance. So to pass the time and help speed things along a little, it's not totally uncommon for thespians to indulge in some adult substances. Drug use on movie sets was much more recurrent in the 70s and 80s, but that doesn't mean it has entirely disappeared from the process. The cocaine might have been swapped out with weed, but just ask any PA tasked with retrieving actors from their trailers, and they'll tell you that drug use is still alive and well in Hollywood filmmaking. Sometimes it doesn't affect the onscreen results much. (Maybe the editor has to use CGI to cover up some red eye.) Other times, it's hard to tell if the actors were supposed to be acting high, or if it was just kinda worked into the scene at the last minute. Here's a fun exercise: Read the following list and then re-watch some of the movies discussed. See if you're able to pick out the scenes where these actors are riding high.