An original concept for a Web-based role play "SurfingGlobalChange" is proposed on the basis of multi-year interdisciplinary teaching experience and constructivist pedagogy. Underlying didactic orientation is towards self-guided learning, acquiring socially compatible "competence to act" in a globalised world, self-optimising social procedures inside teams, process-orientation and peer-review instead of teacher's review. Participating students find themselves in an argumentative battle where they put their marks at stake. A comparison with similar games highlights the increased level of responsibility attributed to and expected from learners using this kind of "digital game-based learning". (Contains 8 tables, 7 figures and 53 notes.)