A multi-installment science fiction or fantasy story, unified by elements such as plot, characters, setting, and presentation, appearing in at least three (3) installments consisting in total of at least 240,000 words by the close of the previous calendar year, at least one (1) installment of which was published in the previous calendar year, and which has not previously won Best Series.

Previous losing finalists in the Best Series category shall be eligible only upon the publication of at least two (2) additional installments consisting in total of at least 240,000 words after they qualified for their last appearance on the final ballot and by the close of the previous calendar year.