The 1982 Movie Blade Runner was adapted from this book.
The world has been ravaged by war and left barely habitable. Almost all the animals in the world have been wiped out. Owning a live animal is a sign of wealth and status. The human population are slowly leaving the shattered planet in favour of the new colony on Mars. Each person who agrees to leave Earth is rewarded with their own personal android as a servant.
But androids are not allowed on Earth. Rick Deckard is a bounty hunter, and his job is to hunt down any androids that slip past Earth security. Each android is a perfect replica of a human and can pass undetected. Except for one thing. Androids have no sense of empathy. A test will reveal this. When Deckard finds his prey he destroys them or “retires” them as it is known.
But this latest assignment to retire six Nexus-6 androids is proving more troublesome than usual. As he hunts his targets down one by one events cause him to begin questioning his beliefs regarding androids, the morality of what he does, and even his own humanity.
At present true artificial intelligence eludes us. But I believe that one day such a thing will exist, and when that time comes the themes covered in this book will have to be considered by all of us.