Hugo Award nominees and winners are chosen by supporting or attending members of the annual non-profit
World Science Fiction Convention, or Worldcon, and the presentation evening constitutes its central event. The selection process is defined in the World Science Fiction Society Constitution as
instant-runoff voting with six finalists, except in the case of a tie. The works on the ballot are the six most-nominated by members that year, with no limit on the number of works that can be nominated. Initial nominations are made by members in January through March, while voting on the ballot of six finalists is performed roughly in April through July, subject to change depending on when that year's Worldcon is held. Prior to 2017, the final ballot was five works; it was changed that year to six, with each initial nominator limited to five nominations. Worldcons are generally held near the start of September, and are held in a different city around the world each year. Members are permitted to vote "no award", if they feel that none of the finalists is deserving of the award that year, and in the case that "no award" takes the majority the Hugo is not given in that category. This happened in the Best Related Work category in 2015 and 2016. == Winners and finalists ==