Armies and Mass Combat

Every realm needs an army because sooner or later someone is going to try their hand at war, either the rulers, one of their neighbours or some horrific horde of monstrosities too vast to be defeated by adventurers.

The rules presented in the Kingmaker Adventure path and Book of the River Nations are fairly complete, but some additions and adjustments are required to iron out some wrinkles and add some useful detail to the system. Except were noted, the standard Kingmaker/BoRN army and mass combat rules apply.

Manpower and Officers

Not everyone in a realm can serve in its armies, either due to age, physical capacity, or the simple fact that a pre-industrial fantasy society requires large numbers of people to sustain itself. The population available for military service is referred to as a realm's manpower and is equal to 1 per 1000 population. Raising military units costs manpower. Lost manpower is regained when military units are disbanded and is slowly recovered over time as the populace ages.

A realm's Officer Corps are the individuals able to lead the realm's armies in battle. These are drawn from the followers of the realm's leaders gained through the Leadership feat, especially the Ruler and the Marshall, plus any other suitable characters that the realm's rulers may have recruited. Each military unit must be assigned a commander from the Officer Corps. It there are no suitable Officers available one of the realm's rulers may chose to personally lead the unit, otherwise the unit may not be raised.

Raising an Army

Raising an army counts as a “building” action for that realm turn. Doing so requires a Loyalty check with a penalty equal to twice the CR of the army you want to raise. If the check succeeds, you spend BP equal to twice the army's CR, manpower sufficient for the new army’s size modifier is deducted and 1 commander from the Officer Corps is assigned to the new army. If the check fails, you spend BP equal to intended army's CR but the army is not raised. The same army may attempt to be recruited again on the following month from the same building(s) at a +4 bonus.

Raising an army costs an amount of manpower equal to the army's size modifier (see below).

Once a building or buildings are allocated to recruiting and training an army, they are unavailable to do so for any other army whether the recruitment is successful or not. The building action is spent whether the recruitment is successful or not.

Certain buildings are required to serve as the focal point of recruitment as well as where the troops are initially trained.

  • A Watchtower or a Fort from can recruit and train any army of up to Small size.
  • A barracks is required in order to recruit and train any army of up to Medium size.
  • A garrison is required in order to recruit and train any army of up to Huge size.
  • A Gargantuan army requires two garrisons within the same block.
  • A Colossal army requires four garrisons within adjacent blocks in the same city district.

Army Size

Armies have a size modifier that affects the costs of resources, both to purchase and when paying consumption costs. A Medium army has a size modifier of 1 and is used as the baseline for almost all resources costs. The size modifier is based upon the theoretical number of creatures composing that army:

  • Diminutive 0.1
  • Tiny 0.25
  • Small 0.5
  • Medium 1
  • Large 2
  • Huge 5
  • Gargantuan 10
  • Colossal 20

When purchasing resources for an army as well as when paying consumption costs, multiply the resource cost by the army size multiplier to determine the total BP cost. Since a “fine army” is an individual creature of CR 9 or higher, it does not normally fall under the purview of consumption costs. The effects of imprisoned or slain rulers are already covered in the Kingmaker rules. Such matters are left to GM adjudication. For those that must know, a Fine Army has a size modifier of 0.01.

Training an Army

Training an army does not count as any kind of realm action and normally begins the same week that recruitment is successful. The building(s) that the army is recruited in are also tasked with training that army, at least at first.

Basic Training depends on the army’s creature composition. Conventional armies have the following training time requirements. Consumption cost of one-half army CR is paid during each week of ‘basic training’. An army training with mounts has a different consumption cost (covered in the resources section) which should be used instead of this cost.

  • NPC-class trained creatures without racial hit dice require (level x level) in weeks, with a cap of 4th level NPCs requiring 16 weeks of training.
  • PC-class-trained creatures without racial hit dice require (level x level x2) in weeks, with a cap of 3rd level requiring 18 weeks of training. PC-class-trained armies round fractional army hp up instead of down.
  • Monsters / creatures with racial hit dice that are not constructs, extraplanar or unintelligent undead require (CR x CR x3) weeks. It is NOT recommended that most monsters even be permitted to be ‘recruited’ into armies except at GM discretion! Creatures that make at least some degree of sense include but are not limited to: centaurs (and similar creatures); dragon type creatures that are not true dragons; giants; certain animals, vermin and the less intelligent magical beasts. One point to bear in mind is that *very* few armies should be comprised of creatures greater than a CR range of 6 – 8 without good reason!
  • Mounts ordinarily should be acquired and trained at the same time as the army that intends to ride them, as noted above.

Leading the Army

Each army must have a designated leader, most likely drawn from the realm's officer corps. A leader with a good Profession (soldier) skill and/or the Leadership feat can assist the army's performance on the battlefield. An army's leader can be a PC or an NPC, but must spend at least 3 days per WEEK (if the army is in the field) or per MONTH (if the army is in reserve, see below), or the army suffers a -1 penalty to Morale. This penalty accumulates each week or month the leader fails to show up. If the army's morale drops to -5, it disbands. The leader can alleviate this penalty by simply showing up the required amount of time; each week or month he does so, the penalty is reduced by 1. The penalty can also be reduced by 1 each week or month by doubling the army's consumption.


Resources is where the army size modifier primarily comes into play, as it applies to all resource costs, both ‘purchase’ and the subsequent consumption costs for them as applicable. Unless otherwise specified, multiply all BP costs for resources by the army’s size modifier. The resources assigned to an army are, in game terms, provided at the end of their basic training.

  • Mounts: BP = CR, consumption = army CR + mount CR (army is mounted). Required buildings: Smith, Stable.
  • Improved Armour (+1 DV): BP 3, consumption 1. Required buildings: Smith.
  • Improved Weapons (+1 OM): BP 5, consumption 1; improved weapons includes alchemical splash weapons such as acid and alchemist’s fire as well as cold iron and silver weapons in addition to masterwork weapons – required buildings: Alchemist, Smith
  • Ranged Weapons (adds ranged capability): BP 2, consumption 0 – ammunition is subsumed in the normal consumption cost as well as within the improved and magic weapons resources – required buildings: Tradesman
  • Magic Weapons (+2 OM): BP 50, consumption 2; magic weapons includes everything provided by improved weapons as well as adamantine and magical weapons – required buildings: Artificer.
  • Magic Armour (+2 DV): BP 15, consumption 2 – required buildings: Smith; any one of: Artificer.
  • Healing Potions: BP 10 (provides 4 draughts that heal army hp = 2x CR), consumption 2.5 per draught used, otherwise consumption 0; draughts can be used post-battle in addition to during battle; healing potions also represent inflict wounds potions given to armies of intelligent undead as well as make whole oils supplied to armies of constructs to affect self-repair; multiple draughts can be pre-purchased and supplied to a particular army if so desired – required buildings: any one of: Alchemist, Cathedral, Herbalist, Magic Shop, Shrine or Temple
  • Poison: BP 6, consumption 6 per battle during which they are used, otherwise consumption 0; multiple “battle loads” can be pre-purchased and supplied to a particular army if so desired; poison resources otherwise act as the poison special ability except that armies not comprised of poison-immune creatures or creatures with the poison use ability inflict a 5% loss (minimum loss of 1 army hp) of their own army hp per phase they make use of their poisons – required buildings: any one of: Alchemist or Herbalist
  • Fortification Builders: 2 BP, consumption 0; permits field encampments to provide some measure of defence for an army that does not move its full speed on a given day – required buildings: Smith or Tradesman; additional basic training required: 4 weeks
  • Shields: as per BoRN, consumption 0. Note that these represent mantlets and tower shields rather than light or heavy shields, which are subsumed within the army’s regular resources
  • Siege Engines, battery of: 15 BP flat cost, consumption 5 BP flat cost; limit of 1 battery “attached” to each army with a minimum army size of Small required; halves speed of the army the battery is attached to; can be detached at any suitable army building, effectively quartering the battery at that location OR they may be detached at any point, abandoning the battery, which removes their consumption cost after the current time period – required building: Siegewright (exotic craftsman), Walls
  • Ships: 10 BP flat cost; consumption 1 per ship; each ship can transport 1 size modifier of troops with or without any attached batteries of siege engines; otherwise as per BoRN – required buildings: Waterfront to construct them & may quarter 20 ships; each Pier may quarter 2 ships


Providing army buildings sufficient to house an army greatly reduces their consumption cost, literally quartering it (from a weekly cost to a monthly cost). Once an army is to march more than a half-week to a destination that also has suitable quartering, full consumption costs are to be paid every week. Siege engine batteries can be ‘detached’ and quartered in any suitable building or fort whether or not an army remains to utilize it. (Failure to pay the consumption cost for that battery of siege engines results in the permanent loss of that battery of siege engines.) Ships can be quartered in waterfronts and piers.

  • A watchtower or fort can quarter an army of up to Small size.
  • A barracks, stronghold or palace can quarter an army of up to Medium size.
  • A castle can quarter an army of up to Large size.
  • A garrison can quarter an army of up to Huge size.
  • A citadel can quarter an army of up to Colossal size.


Mercenaries cost twice as much to recruit and in consumption for a +0 Morale “green” (no tactics) unit led by a competent commander. However, they do not draw upon the realm’s manpower nor its Officer Corps. The default mercenary commander has 5 ranks of Profession (soldier) at a +10 bonus and a +4 ability score bonus applied to his army’s Morale. The maximum size, composition and other details of such mercenary forces are left entirely to GM discretion. It takes a month to recruit such a mercenary army.

Seasoned combat veterans with a higher Morale and 1 or more learned Tactics cost more Consumption (but not recruitment). They also take longer to recruit. Add 50% to Consumption per +1 Morale and +100% to Consumption per Tactic learned. For a mercenary unit with more than 2 Tactics, it is highly recommended that a specific NPC of sufficient skill be determined by the GM – as well as the price he demands (and receives) for his services. Add 1d4 weeks for each +1 Morale and/or each Tactic that unit knows.

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