This paper describes the development, implementation, and assessment of instructional materials for geotechnical engineering concepts using the Environments for Fostering Effective Critical Thinking (EFFECTs) pedagogical framework. The central learning goals of engineering EFFECTs are to (i) improve the understanding and retention of a specific set of concepts that provide core knowledge and (ii) encourage students to recognise and develop critical thinking skills that lead to growth in engineering judgement. The practice of geotechnical engineering deals with complex and uncertain soil conditions, where critical thought and judgement are imperative. Three geo-EFFECTs were created in the context of levee reconstruction, levee permeability, and settlement of a tower structure. Students often provided inaccurate estimates to driving questions set in those contexts; when given opportunities for self-exploration and self-correction in the EFFECT structure, students often achieved more accurate final solutions. Overall, results suggest that EFFECTs have a measurable, positive impact on student learning. (Contains 4 tables and 6 figures.)