If a fundamental goal of schooling is to prepare young people for the unknowable future, why do we assign students so many clearly defined tasks with predetermined solutions? According to the author, the best way to unleash students' problem solving and creativity-and thus prepare them to face real-world problems-is to incorporate complex challenges that teach students to respond productively to uncertainty. This book explains how to foster possibility thinking<\\Q> to help students think creatively and counterintuitively; the process of lesson unplanning, or transforming lessons, activities, and assignments into more complex challenges; four basic action principles to design and solve complex challenges; and the steps for creating legacy challenges, which require students to identify a problem, develop a solution, and ensure that their work makes a lasting contribution. Invite uncertainty into your classroom-and discover what your students are capable of.