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.