Richard Arnold Epstein (born March 5, 1927) is an American physicist, mathematician, and author known for his contributions to game theory, probability theory, and military operations research. He worked at the RAND Corporation during the Cold War, focusing on strategic analysis and decision science. Epstein authored classic texts such as 'The Theory of Gambling and Statistical Logic' and 'Probability and Statistics for Engineers and Scientists,' which are widely used in academic and professional settings. His work bridged pure mathematics and practical applications, influencing fields like economics, engineering, and defense strategy. Epstein's legacy lies in his ability to make complex theories accessible and relevant to real-world problems.