A Rickety Mass Combat System

A while back, I had a chance to look at +Harley Stroh's draft of a mass combat system for DCC RPG. It made me think. He'd used existing ideas (e.g. hit points as "army points," wizard duel rules for combat momentum, the viscitudes of battle, and so forth). I was intrigued by the system, even though he's not particularly satisfied with it at this point, because it satisfies a need I see in both Peril on the Purple Planet and the Against the Atomic Overlord adventure I've written on for Goodman Games (which will be out sometime in 2015). While mass combat is not explicitly included in either adventure, there's strong possibility that it could come into play, depending on what the PCs do. So here are a few ideas of my own. I don't think they're better than Harley's mind you, but they do present another possible approach.

Anyway, some preliminary ideas.

Treating Units and Battle Conditions Like Characters

Each unit on the battlefield gets treated as a character. That is, the unit has a class, stats, armor class, hit points, saving throws, movement, etc. as a player character (or NPC). The units themselves should be treated as one of the martial classes (Warrior or Dwarf). These two classes have distinct functions on the battlefield (see below in class descriptions). Other classes might be used to establish battlefield conditions, or to attach a special power to an existing martial unit, sort like Aspects in the Fate system: They reflect a condition attached to the unit, instead of the unit itself. I'll explain this further, in a bit.

So, functionally, it might break down something like this.

Warriors (normal unit)

• These are the main representations of combat units. Just use as standard warrior of appropriate level.
• Hit points could be rolled or assigned as normal. Alternately, they might be a way to "buy" units (i.e., you get cheaper more plentiful units at 1 hp per level, then cost ascends from there). 
• Level of unit is measure of its veterancy. Veteran units get more hit points and are more formidable in combat. For mass combat there should be a limit on level, however. I think levels 1 to 3 are probably sufficient, though I suppose arguments could be made to make truly elite units with higher levels.
• Armor class is translatable to light (AC 10-12), medium (AC 13-15), or heavy (AC 16-18) troops, with associated to-hit numbers, and with standard effects on movement (even with mounted units).
• Weaponry should simply translate straight across. What are they carrying? If mixed weapons, then take the median or mode average result. If special weapons (e.g., missile weapons, pole weapons or spears), then make sure those advantages get reflected in the way they are used (e.g., pike against cavalry, missile weapon ranged attacks, etc.).
• Number of attacks per round (a function of level) would always just be 1, but the die rolled might go up or down the dice chain for veteran troops. So, a "Level 1" unit rolls a lower die than a "Level 2" unit. I'd probably use a d16/d20/d24 dice chain for green/blooded/veteran units, respectively. For truly elite troops, I'd hesitate to use a d30, but would opt, instead, for a fixed bonus of +1 or +2.
• You could even use Mighty Deeds in various ways: A Mighty Deed of Command to rally troops, a Mighty Deed of Arms to bolster attack or defense for a round.
• Cavalry units are a special case, and are discussed below.

Dwarves (special unit/battlefield condition)

• As units, a Dwarf represents siege weaponry. It is a ranged unit.
• As a battlefield condition the Dwarf represents some kind of fortifications.
• Their attacks represent siege weapon attacks, and their shield bashes represent how well fortifications protect troops in cover.
• Siege weapon units are the only things on the battlefield that can attack fortifications.
• Siege weapon units also can attack other martial units.
• Damage against them reduces them on their attack/defense dice chain. The levels at which this happens, I'm not so sure about. Maybe 3/4, 1/2, 1/4, etc.

Clerics (battlefield condition)

• These are something attached to a regular (warrior) unit, like a group of cultists (if spells are to be employed) or a medical corps (if using the Lay on Hands ability). I think I'd make the person using the Cleric in this way pick one or the other of these powers.
• The cultist condition allows the unit to employ a limited array of spells. Probably Bless and Curse are the main ones, though Holy Sanctuary, Protection from Evil and others are appropriate.
• The medical corps condition allows the unit to heal itself and/or any adjacent units, once per combat round.
• Level of cleric can affect casting rolls as normal.
• Disapproval range works as normal.

Thieves (special unit or battlefield condition)

• Thieves are special units that could be treated as scouts or even (potentially) assassins. 
• As a unit, they would be statted as thieves, including armor, hit points, etc.
• They are effective only when they can remain hidden. To scout effectively, they must use stealth, represented by a die roll, depending on the sort of action attempted (i.e., Sneak Slightly for movement or Hide in Shadows for remaining hidden from the foe until they can best be employed). 
• To attempt to assassinate an NPC Leader (see "Leadership by Player Characters and NPCs," below) they must both accomplish a stealthy action (i.e., Sneak or Hide) as well as make a successful Backstab.
• Whether successful or not, the assassin is always sacrificed by this action.

Wizards and Elves

I see no reason why wizards and elves need to be treated as mass combat units, like the martial units. They are powerful enough, especially in circles of mages, to be used simply as PCs or NPCs. That said, they would function as mass combat "units" for purposes of their use in mass combat.

• They must target a specific unit to achieve a spell effect. 
• It might be that the array of spells used in mass combat should be restricted to a limited list of offensive and defensive spells.
• They can also be targeted as distinct mass combat units, and probably should have the combined hit points of all the wizards/elves in the circle.
• Any spell corruption or misfire will affect ALL the members of the circle.
• Casting times are increased by 1 round per additional wizard/elf in the circle; however, each member of the circle beyond the first adds a bonus equivalent to his/her caster level, up to +3.

Halflings

I have no idea how I would use Halfling units, but welcome your suggestions.

Mounted Combat: Cavalry and Pikes

Warrior units may be designated as cavalry. They get the benefits of being mounted for movement and combat purposes (see DCC RPG rulebook, pp. 87 and 418). Just treat the unit as if it were a mounted warrior.

These mounted units should be designated as light or heavy. Light cavalry is faster and lightly armored. It can perform Mighty Deeds in character with its nature (e.g., the Parthian shot). Heavy cavalry is slower, more heavily armored, and can perform Mighty Deeds in character with its capabilties (e.g., greatly enhanced damage on a charge).

Those defending against cavalry might also be able to prepare the ground to receive cavalry (i.e., by using Dwarves as a battlefield condition), or by equipping a particular unit with appropriate weaponry (e.g., pikes, which might get the same damage benefit as a lance does, but in the opposite direction).

Finally, cavalry might be designated as a scout unit. It would be statted as a mounted Thief. I could see ways in which the Sneak Silently and Hide in Shadows, or even the Backstab rules might be employed for such a unit, but the player or NPC would need to use terrain to achieve surprise in such cases.

Leadership by Player Characters and NPCs

It may be that you want your PCs to be able to take part in this mass combat, as commanders of units or of the whole army. Such a course of action comes with significant benefits, but also with significant risk.

First, the PC or PCs in question must be attached to one or more of the combat units. In all cases, the unit in question must be either a warrior or dwarf unit, usually a warrior.

To provide a leadership benefit to that unit, the player character makes a d20 roll, modified by Personality. Warriors and Dwarves add Personality mod and Deed Die roll to total. Other PC classes add just the Personality mod. In addition, the martial PCs can attempt a Deed of some kind in mass combat. For example, "I drive my unit forward, hitting the center of the foe's line. I want to try to split her unit," or "I wheel the light cavalry to retreat from the charging foe, and attempt a Parthian shot." Like regular Deeds, the main limit is the player's (or GM's) imagination, but in this particular case the Deed should be conceived in terms of mass rather than individual combat.

Only units with PCs/NPCs attached to units already in play get this benefit. However, these PCs/NPCs also take damage when their units are damaged, putting them in peril of dying if things go badly.

Conclusion

Anyway, there you go. That's my "first draft" version of a mass combat system for DCC RPG. I welcome your feedback. What am I missing? What could be added? What are some potential problems with my approach? Let me know.