Worldcon bid committees select one or more guests before the site selection vote. Fans consider it inappropriate for bids to compete on the basis of their chosen guests (so as to avoid having someone chosen by a losing bid feeling that fandom had voted against them personally), so bids do not reveal who their guests are until after the vote, and losing bids generally never reveal who they invited. This is usually treated with the same discretion as the Hugo Awards, where only a few people might know in advance who the guests will be.

World Science Fiction Society