I employ a system of “grade insurance” in my large (450 student) introductory chemistry course. Students use it to guard against the very real possibility of ending the semester close but just below the numerical cutoff for a letter grade. Insurance may be purchased by completing a small number of additional problems throughout the semester as “premiums.” Since it must be purchased prior to the final exam, students do not know if they will finish the semester in a situation where the protection afforded will be needed.