I was listening to Save or Die episode 76 recently and now must throw my ideas for mass combat at everyone. I do apologize in advance for these rather simplistic and not all encompassing rules.
Individual – 1 person
Squad – 4 to 8 individuals
Platoon – 2 to 4 squads
Company – 2 to 4 platoons
Individual – Stat as Henchmen
Squad – HD 2 + Number of Individuals; AC 7 ; Atk 1d6 + number of Individuals (weapon, melee) or 1d6 + half number of Individuals (weapon, ranged)
Platoon – HD 4 + Number of Squads; AC 5 ; Atk 1d6 + (2 + Number of Squads) (weapon, Melee) or 1d6 + (2 + 1/2 Number of Squads) (weapon, Ranged)
Company – HD 4 + Number of Platoons; AC 3 ; Atk 1d6 + (4 + Number of Platoons) (weapon, Melee) or 1d6 + (4 +1/2 Number of Platoons) (weapon, Ranged)
Combining and Disbanding
For convenience round the number of individuals down to the nearest increment when turning individuals into a squad (i.e. Ten individuals = 8 person squad). When disbanding a Squad subtract the number of leaving members rounded up from the squad. If enough Individuals remain in the squad then the squad stays intact (i.e. Three individuals leave an eight person squad leaving five individuals; a four person squad remains).
Use this method for Platoons and Companies as well.
Combat and Damage
For convenience Squads, Platoons and Companies attack and damage as singular entities.
Roll for initiative as singular entity; add number of lesser value as a bonus to initiative (Platoon B rolls a 4 for initiative and add 3 since it is comprised of three squads for an initiative of 7)
Heroes and Mass Combat
If a “Hero” (player character) joins any unit in combat that unit receives a motivation bonus equal to half the Hero’s level.
Magic-User Units in Mass Combat
Magic Users are stated as a normal unit with the exception of spell effect. All spell effects are multiplied by half the number of individuals in the unit. Mage Units can no larger than a 2 squad platoon due to the rarity of magic-users in most settings.