An outline is given of the behavioral properties (axioms) that have been proposed, and to some extent empirically evaluated, concerning uncertain (often risky) alternatives, the joint receipt of alternatives, and possible linking properties. Recent theoretical work has established the existence of three inherently distinct risk types of people—risk seeking, risk neutral, and risk averse—and so evaluations of theories must take respondent type into account. A program of experiments is sketched making clear exactly which empirical studies need to be repeated with respondents partitioned by risk type.