Joko gegen Klaas – Das Duell um die Welt is a German reality series, broadcast on the German television network ProSieben on prime time. It is a show that pins its two stars against one another in a series of challenges all over the globe. Hosts Joachim ‘Joko’ Winterscheidt and Klaas Heufer-Umlauf give each other a series of outrageous and tough challenges in countries all over the world; they know where they're going but have no idea what they will have to do until they get there.