The Empire Strikes Back is a science fiction novel written by Donald F. Glut and first published by Del Rey. It is based on the script of the film of the same name. The novel, like the film, introduces new characters, most notably Lando Calrissian and Boba Fett (though Fett was technically introduced in the earlier, low-canon Star Wars Holiday Special).
Glut’s novelisation was originally released in two forms; a standard edition and a special Young Readers Edition that was condensed into 150 pages. Initial printings of both versions contained 8 pages of color photographs in the middle of the book. [Wikipedia]
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