The process for choosing the Hugo Awards, and the method of establishing and changing the rules, has evolved over the years from the original creation of the awards in 1953.
The Hugo Award started out as a one-step process; there was no separate nominations and final voting, but, instead, a vote among all the works that were considered eligible. You wrote down the work you liked best, and whichever work had more votes than any other work won the award. (This is sometimes called “first past the post” voting, because it works like a horse race. The current system is called “Instant Runoff Voting,” or IRV. It tends to select consensus winners favored by a majority of the voters.)
Starting in 1959, there was a separate nominations ballot, and then a vote among the nominees for the final ballot. The nominators weren’t required to be members of the Worldcon (or any Worldcon) — ballots were freely distributed. In fact, on pg 167 of the May 1962 Analog, there’s an open solicitation for nominations as part of Miller’s “The Reference Library” column (the book reviews section of Analog). And voting on the final ballot was also open until 1961, when the rules were changed to limit it to current Worldcon members.
The rules beginning in 1963 limited nominations to the current and immediately preceding Worldcon, and the procedure stayed unchanged until 2012, when next year’s Worldcon members were added to the group that could nominate.
From the creation of the Hugo Awards in 1953 through the 1963 Worldcon, the Hugo Award categories were determined by each year’s Worldcon committee. The general membership did not control the process until the adoption of a constitution for the World Science Fiction Society. The WSFS Constitution didn’t exist until 1963. There were a set of Business Meeting resolutions, but they hadn’t all been collected or determined as to which were binding, and how, prior to then. The WSFS Constitution was put together by a committee appointed by the 1962 (Chicon III) Business Meeting, headed by George Scithers, and was adopted by the 1963 Worldcon.
Starting with the 1964 Worldcon (the year following the adoption of the first WSFS Constitution), the Constitution indicated what the categories were. From that time onward, the members of the Worldcon controlled what the categories were and how the election process worked by amending the Constitution.
While the specific process has changed from its early days, and the categories have varied over time, one thing has remained constant, and that is that works of both science fiction and fantasy have always been eligible for the Hugo Award. The Hugo Award has never been exclusively for science fiction; it has always included works of fantasy. There never was a time when fantasy was “added” — it’s always been eligible.
Although the categories have changed from year to year and the details of the process have changed (such as when members of the following year’s Worldcon were allowed to start nominating, as of the 2012 Hugo Awards), the current Awards process has been broadly in place since the 1964 Worldcon.
[Much of the content of this page was provided to us by Ben Yalow, WSFS rules scholar, and we extend our thanks to him for the help.]