Harrison Ford portrays Deckard in the fashion that the story line dictates, while adding a great deal of emotion to the seemingly unemotional character. Ford's Deckard appears to be the product of the society as he scours the city in search of replicants.
Hauer's replicant is a strong force in the movie as he shows the machine and the human side of the replicants. The key to Hauer's character was to portray the replicant desperate for more life, but still cunning, manipulative, and dangerous; and Hauer achieved this very difficult combination.
The actress portraying Rachel also showed the emotional fluctualtions of Hauer, but she was not called upon to do any powerful acting. She did create the feeling of artificial life in the first scene and continued it while occasionally using sex appeal and fear. The other actors were mainly bit parts but did create the required scene and mood of the picture.
In comparison to other science fiction movies, Blader Runner has strong acting and uses these actors to enhance the picture itself.