Volume 3 presents substantial advance in the relational model theory and the algorithmic treatment of modal logics. It contains invited and contributed papers from the third conference on "Advances in Modal Logic," held at the University of Leipzig (Germany) in October 2000. It includes papers on dynamic logic, description logics, hybrid logics, epistemic logics, combinations of modal logics, tense logic, action logic, provability logic, and modal predicate logic.