Mass Combat pt.2


Mass combat takes place over the course of three battle phases: the Tactics Phase, the Ranged Phase, and the Melee Phase. A phase doesn’t denote a specific passage of time, leaving the GM latitude to determine how long a mass combat takes to resolve. For example, a battle in a muddy field after a rain could take place over hours and involve several short breaks to remove the dead from the battlefield, but still counts as one battle for the purposes of these rules. If there is an extended break (such as stopping at nightfall to resume combat in the morning) or the battle conditions change significantly (such as the assassination of a commander, the arrival of another army, and so on), the GM should treat each period of combat between armies as one battle. The battle phases are as follows.

  1. Tactics Phase: The GM decides what battlefield modifiers apply to the battle. The commanders each select a tactic their respective armies will use during the battle (see page 237).
  2. Ranged Phase: Any army with the ability to make ranged attacks may make one attack against an enemy army. This phase typically lasts for 1 round (one attack) as the two armies use ranged attacks while they advance to melee range, and then use melee attacks thereafter. The battlefield’s shape and other conditions can extend this duration. If both armies have ranged attacks, they may choose to stay at range and never approach each other for melee (at least until they run out of ammunition, though the Consumption cost of maintaining an army generally means the army is capable of many shots before this happens). Armies without ranged capability can’t attack during this phase, but may still rush forward.
  3. Melee Phase: The armies finally clash with melee attacks. Each commander selects a strategy using the Strategy Track (see page 239), then each army makes an attack against another army. Repeat the Melee phase until one army is defeated or routs, or some other event ends the battle.


In mass combat, the hundreds of individual attacks that take place in one battle phase overlap each other enough that who actually attacks first is irrelevant.

When armies attack, each army attempts an Offense check (1d20 + the attacking army’s OM) and compares the result to the target army’s DV.

If the Offense check is equal to or less than the target army’s DV, the army deals no damage that phase.


If the Offense check is greater than defender’s DV, the defending army takes damage equal to the result of the attacker’s Offense check minus the defender’s DV. For example, if the attacker’s Offense check is 11 and the defender’s DV is 7, the defending army takes 4 points of damage. Because these attacks are resolved simultaneously, it is possible that both armies may damage or even destroy each other in the same phase.

If the Offense check is a natural 20, but that check is lower than the enemy army’s DV, the attacking army still deals 1 point of damage. If the Offense check is a natural 1, that army can’t attempt an Offense Check in the next phase, due to some setback: a misheard order, getting stuck in mud, and so on.

Beyond the Kingdom

The mass combat rules often refer to aspects of the kingdom building rules, such as Loyalty checks and a kingdom’s Control DC. If you aren’t running a kingdom, substitute a Will save for a Loyalty check. Instead of a kingdom’s Control DC, use the primary ability DC of a monster with a CR equal to the party’s APL (see Monster Statistics By CR, Bestiary 291). For example, if the party’s APL is 12, the Will save DC is 21. Instead of a kingdom turn or kingdom phase, use 1 month. Instead of BP, multiply the BP cost by 500 gp.

More Than Two Armies

These rules can also serve in battles where more than two armies clash. In such battles, when your army attempts an Offense check, you choose which enemy army (or armies, if you have multiple armies in the field) it is attacking and apply damage appropriately. On each phase, you may change which army you are targeting. If your kingdom fields multiple armies in a battle, you may want to divide responsibility for these armies among the other players to speed up play.


In some mass combats, the specifics of a battlefield won’t impact either army, but sometimes the battlefield will itself decide the outcome. The modifiers listed below apply only for the duration of the battle. Naturally, the GM should exercise judgment regarding any conditions that don’t seem to apply to one of the armies (such as darkness and an army with darkvision, or fog and an army with scent).

At the GM’s discretion, large-area spells such as move earth might allow armies or commanders to manipulate the battlefield conditions before a conf lict. For these spells to have any effect, they must last at least 1 hour and affect at least a 500-foot square. Likewise, magic items such as an instant fortress (+2 Defense) and spells such as wall of stone (+1 Defense) can create simple fortifications for an army to use in a battle.

Advantageous Terrain: Generally, if one army occupies a position of superiority (such as being atop a hill, wedged in a narrow canyon, or protected by a deep river along one f lank), the defending army increases its DV by 2.

Ambush: In order to attempt to ambush an army, the entire ambushing army must have concealment. The ambusher attempts an Offense check against the target army’s DV. If successful, the battle begins but the target army doesn’t get to act during the Tactics phase. Otherwise, the battle proceeds normally.

Battlefield Advantage: If an army is particularly familiar with a battlefield, it’s OM and DV increase by 2.

Darkness: Darkness reduces all armies’ OM by 2 and DV by 3.

Dim Light: Dim light reduces all armies’ OM by 1.

Fog: Fog reduces damage by half and gives the armies a +2 bonus on Morale checks to use the withdraw tactic.

Fortifications: An army located in a fortification adds the fortification’s Defense to its DV. A settlement’s Defense is determined by the types of buildings it contains, as detailed in the kingdom-building rules on page 212. If the game isn’t using the kingdom-building rules, a typical fortification increases DV by 8.

Rain: Rain affects modifiers to OM in the Ranged phase as if it were severe wind; see Table 13–10: Wind Effects on page 439 of the Core Rulebook.

Sandstorm: A sandstorm counts as fog and deals 1 hp of damage to all armies during each Ranged and Melee phase.

Snow: Snow affects ranged attacks like rain, and affects damage like fog.

Wind: The wind modifiers to ranged attacks apply to OM in the Ranged phase; see Table 13–10: Wind Effects on page 439 of the Core Rulebook.

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