This document introduces a driving question rubric called Tubric that is designed to help formulate open-ended driving questions for project-based learning. The rubric provides categories for the abstract or concrete person or entity posing the question, the action or challenge the question addresses, and the audience or purpose being considered. It encourages using the rubric to craft questions that tackle real-world problems for various audiences and concludes by inviting the sharing of questions developed using Tubric.