The competition for the Miss Universe title has seen many changes, although there have been several constants throughout its history. All the contestants compete in a preliminary round of judging (nowadays called the "Preliminary Competition") where the field is narrowed to a select number of semifinalists. This number has fluctuated over the years. The first Miss Universe pageant had ten semifinalists. For the next two years, the number of semifinalists grew to 16. In 1955, the number dropped to a stable 15, which remained through 1970. In 1971, the number was reduced to 12. That number was further reduced to 10 in 1984. This lasted until 2003, when the number of 15 was reinstated. In 2006, there were 20 semifinalists, the highest number ever. In 2007, the organization announced the Top 15 system would be back, which was also used in 2008 until 2010. In 2011, the results of a fan vote was shown on the screen during the swimsuit and evening gown competitions, but this did not affect the final outcome of the competition. From 2011 to 2013, there were 16 semifinalists, 15 chosen by judges and one chosen through Internet votes. The 16th semifinalist by fan vote has been dropped as of 2015, and the number has been reverted to 15 semifinalists. And in 2016 edition there were 13 semifinalists, 12 chosen by judges panel from the quarantine to the preliminary night and one chosen by Twitter and Vodi app.
In the early years, the contestants were judged in swimsuit and evening gown only. In later years, the contestants also competed in a preliminary interview round in a one-on-one meeting with each individual judge.