"Enthalpy Costs" is a simple card game created to assist students in developing proper Lewis structure drawing skills. Score keeping is accomplished by tracking the enthalpy changes associated with bond-making and bond-breaking processes during formation of molecules represented by proper Lewis structures. Playing the game requires the student to practice both correct Lewis structure drawing and calculation of enthalpy changes associated with chemical bonding. Since the game process provides the student with several options for each "hand", he or she is also forced to think about the relative energy costs of bond-breaking and bond-formation and will gain understanding of the concepts behind the calculations. (Contains 8 tables and 4 figures.)