Dear Rich: I'm thinking of developing a board game based on a friend's idea. The game title and game roles are borrowed directly from a movie. Can I use the movie title and characters' names in my game? Secondly, I want to use characters' portraits from the movie in my design. What if I just draw the portraits by myself, say, in cartoon style? Third, the game rule is based on a party game called Mafia. Is that legal? Before we begin, can we send a shout-out to anyone asking Dear Rich questions about using a movie or TV show as the basis of their book, movie, t-shirt, or coffee mug? Regardless of the legal analysis provided by the Dear Rich staff, if the owner finds out about what you're doing, you're likely to get hassled. (Yes, we're talking about "sue first, ask questions later.") We're not advising you give up your legal rights, but if you have limited resources, we do advise against investing them in a project with a built-in hassle factor.
Okay, the short (and long) answers to your questions are: (1) copyright does not protect titles, but may protect a title when used in connection with other important elements (like character names); trademark law may also protect the movie title, (2) your drawings may or may not avoid copyright problems (it depends on whether they're considered derivatives) and may or may not avoid right of publicity claims (it depends on how the game is marketed), and (3) the psychologists who invented Mafia don't appear to claim proprietary rights, so you're free to base your game on it as long as you don't copy somebody else's derivative version. Take-away points: enjoy the game; don't sell it.
