Mass Combat


This system was designed specifically for the Cambria Campaign, which features 18th-century warfare. This is meant to be a fast, lightweight, easy to learn solution to handle mass combat within a D&D session without getting bogged down in unnecessary detail. 


The core of the system is the “unit”, which represents one group of troops of a certain type: infantry, cavalry, or artillery. These types are further broken down into subtypes. Units are represented on the map with a symbol indicating what type of unit they are and approximately how large the unit is. 

Unit Stats

Each unit has its own set of statistics to represent its strengths and qualities, which are as follows:

  • Quality Rating (QR). This represents the level of training, quality of equipment, and amount of experience a unit has and acts as a modifier to any roll the unit makes as well as determining a unit’s Armour Class (AC). Quality ranges from 0 (fresh recruits) to 5 (elite).
  • Strength (STR). This represents the size of the unit and acts as a health pool. Unit size also determines the number of hits (damage) it deals. The higher the strength, the larger the unit, the more hits it can take before it is out of action. When a unit drops to 0 strength, it is removed from the field. This system assumes that you are using units of company strength or equivalent (2 STR), but any scale can be used as strength is really just an arbitrary value. 
  • Damage: Mass Combat doesn’t utilize damage dice. Instead, each unit deals damage equal to half its strength, rounding down (minimum of 1). At the standard “company” scale, this is easy: each unit deals 1 damage. Each damage a unit takes reduces its Strength by 1. Certain features and upgrades can increase the damage a unit does.
  • Speed (SPD). This represents how many hexes a unit can move each turn. All units can always move at least 1 hex, as long as they have an unoccupied hex to move into. 
  • Range: This represents how many hexes away a unit can engage enemies. 
  • Armour Class (AC). This represents a unit’s armour or ability to avoid taking damage. AC equals 10 + the unit’s Quality Rating. 

Unit Types

Each unit type has unique characteristics and features. Units can be trained to acquire new features.


Infantry is the basic unit used in mass combat. Infantry is subdivided into two types: Infantry and Light Infantry. Most infantry types have a speed of 2 and a range of 2. Light infantry typically has a range of 3. 

All infantry units have the following feature:

Form Square. Cavalry melee attacks made against this unit have disadvantage.

Light infantry units have the following additional features:

Loose Formation. Ranged attacks made against this unit have disadvantage, but melee attacks made against this unit have advantage.

Scouts. This unit has advantage on Perception checks. 


Cavalry is a highly mobile, versatile unit that can be used to outmaneuver enemy units. Cavalry is subdivided into four types: Heavy Cavalry, Dragoons, Light Cavalry, and Lancers. Most cavalry types have a speed of 4 and a range of 1 (melee). Dragoons typically have a range of 2. Light Cavalry has a speed of 5. 

All cavalry units have the following feature:

Charge Through. Cavalry are able to pass through an enemy hex if they successfully attacked that unit and have movement available. This movement must be in a straight line to the other side of the charged unit. This is only possible if that hex is unoccupied, as per normal movement rules.

Light Cavalry units have the following additional features:

Expeditious. This unit may disengage for free. 

Scouts. This unit has advantage on Perception checks. 

Lancers have have the following additional feature:

Lance. Lancers ignore the Form Square ability. 

Dragons are effectively mounted infantry, and gain the benefit of infantry features in addition to their cavalry feature. Heavy dragoons gain Form Square while Light Dragoons gain Form Square and Loose Formation.


Artillery provides commanders with standoff capabilities and can target enemies at range. Artillery is subdivided into two types: Foot Artillery and Horse Artillery. Most artillery types have a speed of 1 and a range of 6. Horse artillery units typically have a speed of 3 and a range of 5.

All artillery units have the following feature:

Barrage. Units hit by an attack from this unit have disadvantage on attacks made until the start of the artillery unit’s next turn.

Monstrous Units

The monstrous units category is for units that consist of only a single (or handful of) particularly large and/or powerful creatures, such as dragons or unique siege weapons. Speed, range, and features are unique to the monster in question. 

Rounds of Combat

Mass combat rounds function the same as character-scale combat, beginning with a check to see if any units are surprised, followed by an initiative roll made by each unit on the field. Each unit then takes its turn moving and taking actions. 


Perception checks (and passive perception) are handled differently in mass combat. Instead of utilizing Wisdom (Perception), mass combat units utilize their quality rating. A unit’s passive perception is 10 plus their quality rating. If a unit must make a perception check, they do so by rolling a d20 and adding their quality rating. 

Rolling Initiative

Initiative rolls are made by rolling a d20 and adding the unit’s Quality Rating (QR). Ties can be broken by the unit with the higher quality rating, or by having the units roll again until there is no tie.


The mass combat rules use a timescale different from the character-scale combat rules, with 1 round representing 1 minute of action. This timescale accounts for the time and complexity needed to maneuver hundreds or even thousands of combatants.


Each unit may move up to its speed on its turn, which is measured in hexes. This movement can be broken up, as in character-scale combat. Units can pass through friendly units without penalty, but cannot pass through enemy units. Movement must end in an unoccupied hex. If there are no available unoccupied hexes for a unit to move into, then that unit cannot move.

Adjacent Hexes

When a unit moves into a hex that is adjacent to an enemy, it is considered to be in melee. Units in melee cannot move unless they first take the Disengage action (see below). Units in melee can only attack units that they are in melee with. Units cannot engage other units that are locked in melee with ranged attacks, they must either charge and join the melee or choose another target.

Actions in Combat

A unit can take one (and only one) of the following actions on its turn:

  • Dash. The unit spends its action to move again, effectively doubling its movement speed for the turn. 
  • Disengage. The unit spends its action to disengage from melee combat, moving one hex away from its opponent. 
  • Attack. The unit spends its action to attack (see Resolving Attacks). 

Resolving Attacks

To resolve an attack, the attacking unit first makes an attack roll by rolling a d20 and adding its Quality Rating. The result is compared to the target unit’s Armour Class. If the attacker’s roll meets or exceeds the target’s AC, then the attack hits, and the target unit loses one Strength. 


Range is measured in hexes, and all units have specific ranges they can attack other units. When a unit is placed on a hill or other elevated position, its range is doubled.


Morale represents a unit’s willingness to fight. Certain situations may force a unit to make a Morale Check to see if it maintains its resolve. If a unit fails a morale check, it loses one Strength. Units must make a morale check in the following situations:

  • The unit is reduced to half or less of its starting Strength. 
  • If a friendly unit within 2 hexes of the unit is eliminated. 
  • The unit is targeted by something which causes Fear.

A morale check is made by rolling a d20 and adding the unit’s Quality Rating. The DC for this check is 10.

Damage & Recovery

Units take damage whenever they are hit by an attack or fail a morale check. Each time a unit takes damage, its Strength is reduced by 1. When a unit drops to 0 Strength, it is considered to be Destroyed and is removed from the field for the remainder of combat. 

Regrouping Destroyed Units

Units “destroyed” in combat may not actually be permanently destroyed. There is a chance that the unit may regroup following the battle and return to your service. To check if a unit regroups, you make a Regroup Check. Roll a d20 and add the unit’s Quality Rating, with a DC equalling 10 + the units Strength rating. This simulates the fact that smaller units are more tightly knit and are able to remain, and regain, cohesion better than larger units. 

Restoring Strength

Units that take damage in battle are reduced in Strength until reinforced. Reinforcement is beyond the scope of these mass combat rules and is handled outside of combat, relying on a number of roleplay factors. 

Player Characters in Mass Combat

Interfacing player characters with mass combat is accomplished in one of two ways: Taking Command, where player characters each take command of individual units. The second is engaging in regular combat within the greater battle. 

Taking Command

Player characters may be able to take command of individual units (provided that the unit recognizes the authority of that character!). When a player takes command of a unit, they may add their Charisma modifier to any roll the unit makes during combat.

Regular Combat

This works just like any other regular combat situation, with the focus zooming in on the player party. This effectively pauses the mass combat while this is resolved.

18th Century Unit Organization

Strength vs Unit Size

As mentioned earlier, Strength refers to a unit’s size. In the Cambria Campaign, this refers to the unit’s level in the overall military hierarchy. See the following table to see how size relates to unit size:

StrengthUnit SizeDescription
1Platoon~40 troops
2Company2 Platoons
4-12Battalion/Squadron2-6 Companies
12-84Regiment3-7 Battalions
36-336Brigade2-4 Regiments
72-1344Division2-4 Brigades
144-5376Corps2-4 Divisions
288-21504Army2-4 Corps

As you can see, a unit’s strength can be highly variable as you climb up into the larger scales. This system is best played on the lower end of the scale, as it best allows for realistic deployment of units on the battlefield (not to mention that it doesn’t require a calculator for damage calculations!).


Line infantry generally deploy as battalions, which consist of 4 to 8 (though typically 6) companies. There are usually 4 line infantry companies, 1 grenadier company, and 1 light infantry company within a battalion. This mass combat system is best played at the company level, but to speed things up it can be run at the battalion level (or even higher), though you do begin to lose the fine control and realism due to oversimplification at the larger scale.

An infantry company is represented as having 2 STR. An infantry battalion’s (the next step up in organization) has a strength equal to 2 x the number of companies it contains (typically 6 companies, so 2 x 6 = 12). The next scale down is the platoon, of which there are two per company. An infantry platoon is represented as having 1 STR and is the smallest unit that can be used in mass combat.


Cavalry are deployed as “Squadrons”, which are technically battalions. Each cavalry squadron has two companies. Even though infantry are played at the company level in this system, cavalry are deployed at the squadron (battalion) level. 

A cavalry squadron is represented as having 4 STR. A cavalry company is represented as having 2 STR. There are two platoons in each cavalry company, and they are represented as having 1 STR. 


Artillery are deployed as batteries, which consist of 6 to 8 guns (a mix of cannons and howitzers or mortars). Batteries are equivalent in strength to a company and fall into the same place in the organizational hierarchy. 

An artillery battery is represented as having 2 STR.