There are a few factors that go into the billing order, and a couple of them came together to get Jack Nicholson top billing in 1989's "Batman."

Nicholson actually had it written into his contract that he be billed first (he had a lot of other wacky stuff written in there, such as the stipulation that he not be scheduled to film during Los Angeles Lakers games).

He was (and still is) a far bigger star than Michael Keaton, who played the titular Batman, so the studio was probably happy to give him top billing -- they might have even done so voluntarily, as they often do.

Another prominent DC Comics hero-villain pairing got the same treatment in 1978's "Superman," in which Gene Hackman, who played Lex Luthor, was billed above acting newcomer Christopher Reeve in the Superman role. (However, neither of them got top billing -- that went to much bigger star Marlon Brando for his much smaller role as Jor-El.)

These are all exceptions to the general rule of giving top billing to the person playing the main character. That usually lines up with the fame factor -- the biggest role usually goes to the biggest name.

But when it doesn't, what we see is there really aren't any rules -- it's all deal-making and compromise.

Have a question? Email us at questions@tvtabloid.com. Please include your name and town. Personal replies will not be provided.