The Mass Combat Supplement to OD&D titled Swords and Spells contains a rather extensive section on Morale. I think one can see influences from both Chainmail and OD&D as this system develops. Likewise, several ideas carries over into AD&D. When to check Morale: Base Morale Scores: Adjustments for different creatures, troop types, formations, positions, etc.: Additional circumstantial bonus: What happens upon a failed Morale check: