Review of the various different versions of Blade Runner and how comparing them tells us a lot on how to use exposition in script writing.
"Considering how much of a box-office flop it was in 1982, it is incredible to see the buzz of excitement surrounding the 25th Anniversary special release of Blade Runner on DVD in a brand new 'Final Cut'.

Blade Runner is not the first flop to gain cult status on home video, yet the film is notable for many other reasons. Firstly, as an ongoing work-in-progress, the film has now reached its fifth version. George Lucas may have revisited his Star Wars films more than once, but even he would balk at the number of times an editor has started from scratch with Ridley Scott's piles of dystopian celluloid."