Awards are also given out for published literary works in the novel, novella, novelette, and short story categories.
Members may then vote on the ballot throughout March, and the final results are presented at the Nebula Awards ceremony in May.
The Christopher Nolan Batman movies, Battlestar Galactica, Buffy the Vampire Slayer, and Doctor Who franchises have each had two nominations, but no wins.
Hayao Miyazaki, Christopher Nolan, Joss Whedon, and The Lord of the Rings screenwriters have had the most nominations, with three each.
Entries with a gray background and a plus sign (+) mark a year when "no award" was selected as the winner.