Science Olympiad is an American team competition in which students compete in 'events' pertaining to various scientific disciplines, including earth science, biology, chemistry, physics, and engineering. Over 7,300 middle school and high school teams from 50 U.S. states compete each year. There are multiple levels of competition: invitational, regional, state, and national. Some states or private groups offer 'invitational' tournaments as practice for regional and state competitions.