I know actors improvise their ...
Words can never hurt me: Anthony Hopkins
Question: I know actors improvise their lines all the time in comedies, but recently I learned that Anthony Hopkins improvised many of Hannibal's lines. I also recently learned from the documentary Hearts of Darkness: A Filmmaker's Apocalypse that Marlon Brando improvised much of his dialogue in Apocalypse Now. So now I'm curious: How often do actors, outside of comedies, improvise their lines?
Answer: All the time. OK, not all actors all the time, but the practice of ad-libbing or altering lines is an entrenched part of film acting and one of the things that drives screenwriters out of their minds. Especially if they come from the theater: In theater, the script is sacrosanct and no one messes with it except with the express consent of the playwright (assuming someone dares to ask). In film, scripts are usually treated as a kind of outline — not only is the dialogue up for grabs, but pieces of the plot are frequently rewritten after the film has started shooting, with or without the assistance of the original writer(s). Consent isn't even an issue: It's a given that once you sell your script, you've thrown it to the wolves and the best thing you can do for the sake of your own sanity is back off and let the pieces fall where they may. That's why so many screenwriters want to be directors — they figure that as directors they'll have more control over the final outcome.
Clearly, bit players don't get to exercise their creativity by changing their two and a half lines. They say what they're told to say, collect their paychecks and hope to work another day. But featured actors like Marlon Brando and Anthony Hopkins — the kind who get hired because their names are seen as a guarantee of box-office draws (whether that actually turns out to be the case is another matter) — throw their own ideas into the mix all the time. Sometimes that's a good thing and sometimes it's not, but it's the way the game is played.