Explored the relative merit of risk dimension (probabilities of winning and losing, and amounts to be won or lost) and moment (expected value, variance, and skewness) explanations of decision making under risk, using pairs of specially constructed duplex gambles. Ss were 40 undergraduates. The explicit (displayed) probability values were different for each gamble in a pair, but the underlying distributions were identical. Preferences among these gambles were related to relationships among the displayed probabilities. This supports the concept of gambles as multidimensional stimuli to which Ss respond on the basis of displayed values on a set of risk dimensions. A preliminary model of the decision process is presented in flow-chart form. (PsycINFO Database Record (c) 2006 APA, all rights reserved)