Blade Runner ending explained

What happens

Roy Batty saves Deckard on a rooftop, then dies, and Deckard goes home to find Rachael. A folded origami unicorn left by Gaff is waiting for him. Its meaning hints that Deckard himself may be a replicant.

The last image

Deckard leaves with Rachael, having found the origami unicorn Gaff left behind.

Two readings

1 · Deckard is a replicantThe unicorn suggests Gaff knows Deckard's private memories, so those memories may be implanted too.

2 · Deckard is humanThe film never confirms it, and Harrison Ford played him as human.

What it says

The ending asks what makes anyone human, if it isn't birth. Roy, a machine, shows mercy; Deckard, a hunter, may be made too. Leaving his nature open lets the film argue that feeling matters more than origin.