Ludo Waltman presents principles for responsible university ranking. He discusses 10 rules for ranking universities, including that one size does not fit all universities, rankings should be transparent about their methodology and data, and they should acknowledge uncertainty. He then highlights the 2019 edition of the CWTS Leiden Ranking, which newly includes indicators of open access publications and gender diversity among authors. Waltman concludes by emphasizing the social responsibility of both rankings and universities to encourage responsible behavior from rankers.