Each invited country sends one team, the host country may participate with two teams. The teams consist of five students from secondary schools (no universities), with one student (Captain) representing the team during the Physics Fights. Each team is supervised by two teachers.
In preparation for the tournament, 17 "open" tasks are defined annually by an International Organizing Committee and published on the Internet in early autumn (www.iypt.org). The tasks come from many areas of physics, often including tasks from other natural sciences.
In preparation for the IYPT, the teams work on these questions, the aim being to find creative, conclusive solutions and to present them convincingly as a team of reporters. An opposing team (opponent) discusses this proposal with the reporter team in a so-called Physics Fight. Another team observes the fight and, as a reviewer team, evaluates both the reporter and the opponent. All teams take part in five Physics Fights, where they act as Reporter, Opponent or Reviewer. An international jury evaluates all participating teams after each fight. Grades from 1 to 10 are awarded, with different weighting depending on the role the team played in the fight.
Since 2014 the German team is determined in a separate competition a few months before the IYPT. At the German Young Physicists' Tournament (GYPT) the students fight according to similar rules as at the IYPT. The same tasks will be worked on as later on in the IYPT. Finally, the German national team is put together from the best GYPT participants.