A scenario is a rich and detailed portrait of a plausible route to a future world, including issues and decisions that might have to be faced as the future unfolds. In this chapter, we are most interested in scenario-creation processes that involve inputs from more than a single person, involve feedback, and may use quantitative models to help establish a foundation for the scenario story. Several interactive methods and applications are described, including (1) use of Delphi questionnaires to collect suggestions for scenario content and scenario axes, that are the major dimensions that define the domain of interest; (2) redrafting a scenario story based on feedback from reviewers; (3) integrating a Cross Impact Matrix, Futures Wheel, or other modeling system to help assure internal self-consistency and quantitative rigor; and (4) allowing the audience to determine the course of the scenario at key decision points. Also described is a clustering approach in which a multitude of scenarios is constructed, each of which differs in input assumptions resulting from uncertainties associated with the variables and the assumed policies. The chapter concludes with a brief speculation about the future of interactive scenarios: multi-mode presentations so realistic that users feel they are in the scenario world and make simulated decisions accordingly.