Science Olympiad is an American team competition in which students compete in 23 events pertaining to various fields of science, including earth science, biology, chemistry, physics, and engineering. Over 7,800 middle school and high school teams from 50 U.S. states compete each year. U.S. territories do not compete; however, since 2012 high school teams from Japan have competed at the national tournament as unranked guests. Science Olympiad is not associated with the International Science Olympiads, which is a group of science competitions with their own rules and objectives.