In these notes, Professor Kreps surveys the standard models of choice under uncertainty that lie at the heart of microeconomic theory. Choice and preference, ordinal utility, von Neumann-Morganstern utility and utility functions for money, and subjective probability and subjective expected utility are among the standard topics covered. These notes provide a rigorous but accessible introduction to the theory of choice for mathematically inclined undergraduates and/or graduate students in economics, finance, and related disciplines.