The interpretive theme is the most important sentence an interpreter inks on paper. Despite its centrality to thematic interpretation, no single work has dedicated itself entirely to the art and craft of strong theme writing until now. The Interpretive Theme Writer's Field Guide builds on Sam Ham's 30-year thematic interpretation research legacy. While leaving communication theory to his books, this companion offers writers strong theme examples, updated theme writer´s worksheet, inspirational quotes, technique highlights, and exercises, including the use of AI generators to craft themes. The second edition also includes new chapters on development psychology, presentation structures, a glossary, an essay on ChatGPT and theme writing, and much more. With contributions from Ham, Ted Cable, Shelton Johnson, Thorsten Ludwig, Don Enright, Judy Fort Brenneman, Kylie Christian, Michael Glen, and other voices from around the English-speaking world, this Field Guide serves at the desk, in the museum exhibit hall, on the park trail, or at an archeological site. It recognizes that teams, even communities, create natural-cultural heritage themes, and introduces the Interpretive Framework methodology to facilitate consensus community-based theme writing.