Welcome to *The Prisoner’s Dilemma*, the problem column/collection of the Prison Math Project (PMP). New problems (and solutions to previous problems) will appear here and in the newsletter of PMP three to four times a year. Everyone is welcome to participate, so do send in your solutions and problem proposals to dilemma at pmathp.org.

#### Problem Warden

The current “Problem Warden” of *The Prisoner’s Dilemma* is Glen Whitney. Glen’s roles in life have included math professor, financial quantitative analyst, parent, founder of the National Museum of Mathematics, author of Studio Infinity, and *Playground* Editor for Math Horizons, the undergraduate math magazine of the Mathematical Association of America. All of these roles have been infused by the joy of math and Glen’s passion for sharing that joy with others.