High school students who have qualified at A2, B1 or B2 level in a Nationale Deutscholympiade (NDO), or any other accredited national selection procedure, are eligible to compete in the IDO. Contestants must be between 14 and 17 years of age.
The following persons are not eligible to take part in the IDO:
- Students whose mother tongue is German or who have at least one native German-speaking parent.
- Students who have lived for more than six months at a time in a German-speaking country.
- Students at German schools abroad or private schools whose principal language of instruction and communication is German.
- Students who are already of legal age (18 or older).
- Students already enrolled to study at a university.
- Students who provide false information about themselves will be disqualified and/or stripped of their titles.
- Two contestants per country, whether at the same or different language levels, may compete in Dresden.