This Strategic Probability, A Card Game Activity directly supports NGSS Standards MS.ETS.1.1–1.4: Students will apply mathematical reasoning and data analysis to engineer, test, and improve design solutions by identifying problems, evaluating and comparing solutions with quantifiable data, and using models and iterations to refine their designs. The purpose of this 45 minute, 5E investigation is to use mathematical reasoning and probability to develop, test, and refine strategic approaches in a competitive card-based game. In this activity, students will play a custom math-based card game that integrates number operations, probability, and data collection. Students will record scores, identify winning strategies, and analyze performance using averages and trends. They will use their findings to revise strategies, reflecting the iterative engineering design process. Optional extensions allow students to create custom rules, explore probability types, and apply other math concepts like fractions, exponents, or algebra. This package includes powerpoint resources, a lesson plan, instructor activity guide, students activity guide, response worksheet, answer key, and digital response worksheet. Just print, prep, and it’s ready to go.