Curricula differ from school to school, but generally include German, mathematics, informatics/computer science, physics, chemistry, biology, geography, art (as well as crafts and design), music, history, philosophy, civics / citizenship, social sciences, and several foreign languages.
For younger students nearly the entire curriculum of a gymnasium is compulsory; in upper years more elective subjects are available, but the choice is not as wide as in a U.S. high school. Generally academic standards are high as the gymnasium typically caters for the upper 25-35% of the ability range.
Schools concentrate not only on academic subjects, but on producing well-rounded individuals, so physical education and religion or ethics are compulsory, even in non-denominational schools which are prevalent. The German constitution guarantees the separation of church and state, so although religion or ethics classes are compulsory, students may choose to study a specific religion or none at all.