30 Things You Didn't Know About Tim Burton's Batman

20. The Film Was Constantly Rewritten During Shooting

Batman's three months of shooting were said to be a seat-of-your-pants production and a trial-by-fire for all involved, with the script constantly being re-written during filming.

While shooting the film's climactic cathedral sequence - which wasn't in the original green-lit script - Jack Nicholson even had to ask Burton what was going to happen, and Burton himself wasn't quite sure.

Major changes to the third act also came late in the day after Kim Basinger convinced Burton and others that Vicki Vale should be part of the climax. As such it's quite remarkable that the final movie feels quite so coherent and holistic.