With AD&D, morale became a percentile and was now a moving number rather than a fixed value. As far as implementation in the EMP campaign, I'm still torn between an easy to use single value for any given monster or using a calculation to determine morale. At the moment, due to my rules on cavalry charges and shock attacks, morale stands at a value between 2-12 and resolves with a 2d6. However, the need for dynamic morale is present in at least one aspect, and that is casualties.
Popular cavalry tactics of the time might incorporate a volley or two of fire from pistols followed by a charge with sword or lance. Obviously, the discharge of pistol shot just before the moment of the charge was to break the cohesion of the defenders to enable a more devastating charge. This application was particularly important for firearm units to break through pike units, especially pikemen that were not properly supported. So morale should be affected by casualties, so let's see how we can model this with 2d6 morale values.
Alexis has an elegant solution he lifted from a Napoleonic war game. Simply put, every time a force suffers 50% casualties, its morale gets 1 point worse and must make a new check to remain in the fight. And there are plenty of morale rules spread throughout different wargames. I feel it is difficult to assign a proper morale scheme and would rather try through trial and error and what feels right in game play. So for the time being, we'll start here in the design phase and modify through play:
Enemy morale drops by 1 point for every 25% casualties (based on the original number of men) that it suffers and must check morale to continue the fight. For example, a group of 12 orcs may have 7 morale. After 3 have been killed, their morale drops to 6 and they must check again. Morale drops to 5 at six dead and then to 4 at nine dead.
So to use an old example, a group of regular soldiers armed with pikes would have a base morale of 7 but a morale of 9 during a charge. If a cavalry attack were to begin with a pistol barrage that inflicted 25% casualties, morale would drop to 6 and force a check. If the pikemen pass, their new morale for the upcoming charge would be 8. The cavalry charge has a good chance at succeeding in breaking unit morale with a barrage of fire and then a fair chance during the followup, more risky, charge engagement.
For now, this will sit on the shelf until it can be play tested.