Cortex System Mass Combat Rules


The Heart of the MatterÖ

The opposing forces of each army are broken down into specific types of units, which are typically, infantry, archers, and artillery. These units will range in size from 50 to 500 soldiers with the GM having final say. Each individual unit will have an abstracted value that represents the unitís weapons, armor, training, and morale called a Unit Rating, while the sum of the individual units is called the End Strength. A commander leads each unit and can be either a PC or a NPC and the army also has a commander.


During the fight, the commanders roll an Opposed Roll of their Intelligence + Perception / Strategy skills, as modified by Unit Rating and specific strategic or tactical advantages. The results of the roll will resolve the winner for that Combat Round and the difference becomes a running tally of an ongoing Complex Action that will determine the victor of the battle and the amount of casualties suffered by both sides. As an option for PCs, they can roll against their individual Intelligence + Perception / Tactics skill find out how each of them fared in the Combat Round as modified by the amount of Danger they expose themselves to.


Mass Combat Rounds

1. Establish the exact composition of each army based on each unitís type and Unit Rating (UR). Using the sum of the URs, determine the End Strength (ES) of both forces

2. Each PC chooses the level of Danger they wish and rolls their Tactics.

3. Determine Commanderís Bonus based on strategic or tactical advantages

4. Resolve results of Opposed Rolls with victor adding to their Complex Action tally

5. PCs on the losing side will determine their Fate based on the results of their own Tactics roll, level of Danger, and Commanderís roll.

6. Assess casualties to each side and adjust ES for both sides.


End Strength

An army is comprised of units, usually of different types and capabilities to provide a balanced fighting force. The relative strengths of each of these units will determine the armyís total strength or End Strength. The specific power of each unit in an army is reflected by the Unit Rating of those formations.


Unit Rating (UR)

Each type of unit has a basic rating and this rating is modified by weaponry, experience, training, and morale. The result of multiplying the basic rating by the modifiers and number of soldiers in the unit yields the final UR.


Unit Type and Equipment

Each formation has a designation: Infantry, Archer, or Artillery and based on their equipment can be light, medium, or heavy. A light unit has very limited armor beyond light shields and use slings, javelins, and short swords. Medium units wear reinforced leather armor with large shields and are armed with spears, swords, and axes. While their level of armor is the same, for a unit to be considered heavy, they have to be armed with pikes, swords, and axes.†††




Experience and Training

The true strength of a unit is far more than numbers, weapons, and armor. What turns a good unit into a great unit is the amount of training they have with their weapons, how much experience in battle they have had, and their level of esprit de corps. Soldiers that fight as individuals are called Irregulars, while a group trained to fight as one are considered regulars. There is an old adage that more you sweat in training, the less you bleed in combat. Units have three levels of training: Green, Experienced, and Veteran. These same ratings are used for their amount of actual combat experience. Each of these modifiers affects the unitís UR.


Unit Rating Modifiers


Light +3

Medium +4

Heavy +5

Irregulars -1/2 UR (round down)

Ranged Weapons

Sling, javelin +1

Ordinary bow +2

Longbow, composite bow or crossbow +3

Pistol or other short firearms +3

Rifle or other long firearms +6

Small Ballistae +15

Large Ballistae, Small Siege Engines or Light Artillery +25



Level††††††††††††† Basic Rating †† Morale Check(Willpower +††††††††††††† Morale Rating

††††††††††††††††††††† Modifier††††††††† Discipline)

Green†††††††††††† 1.0 ††††††††††††††† d6 + d6††††††††††††††††††††††††††††††††††††††††††† AVERAGE (35)††††††††

Experienced††† 1.5 ††††††††††††††† d8 + d8†††††††††† †††††††††††††††††††††††††††††††† HARD (55)

Veteran†††††††††† 2.0†††††††††††††††† d10 + d10†††††† †††††††††††††††††††††††††††††††† FORMIDABLE (75)



Level††††††††††††† Basic Rating Modifier

Green†††††††††††† 0.5

Experienced††† 1.0

Veteran†††††††††† 1.5

Example: Lemurian Guards have a basic rating of UR3 with a +3 for light infantry, +2 for bows. They are Regular, Green troops, Experienced with their weapons, yielding a final UR of 8.



One of the most critical elements of a unit is the quality of the individual in command. If the unit knows their leader is good at what they do, they will be inspired and fight harder. For every two skill steps above d8 in Tactics of the commander, the unit gains a level in their Morale Rating, thus a Green unit with a commander with Tactics d12 would have their Morale Rating increase to HARD. However, an incompetent of inexperienced leader will drag even a veteran unit down. For each skill step below d8 in tactics, a unitís Morale Rating drops a level. Example: a Veteran unit saddled with a raw lieutenant as a leader with only Perception d6, and thus no specialty in Tactics would reduce the unitís Morale Rating to HARD.



The nature of melee combat is deadly and surviving a fight so close to the enemy is largely a function of skill and luck. How a PC fares from moment to moment is a large battle will depend on the amount of Danger they are will to endure. During each Combat Round, each PC in the fight must roll their Fate, which is a test against Intelligence + Perception / Tactics. The normal risks that are part of close quarters fighting do not affect this test. A PC taking extra precautions to reduce their level of Danger will gain a one-step bonus to their skill, whereas, a PC choosing to accept a High amount of Danger is a one-step penalty to skill



During each Combat Round, there is a chance a PC may sustain some injury. Exactly how much injury a PC sustains is based on the characterís fighting skills. Add the die rating in the PCs best offensive skill (typically Melee Weapons Combat) and their best defensive skill (usually Athletics / Dodge) to determine the PCís Skirmish Rating by consulting the following table.
















Skirmish Rating















Each Combat Round, the PC must roll against a HARD Attribute (usually Agility) + Skirmish Rating test. How successful the character is in the roll determines if the PC sustains any damage. When the PC rolls for damage, they get their full armor rating and can use Plot Points or Things Go Smooth to reduce or re-roll damage. The amount of damage rolled is on the following table:


Fate Roll




d12+d10 B


d12+d4 B


d10 B

Extraordinary Success

d2 B



The benefit of accepting a higher level of Danger in a fight is that the PC has a chance to receive greater recognition for their bravery. Based on the result of the Fate roll the character may get to make a second skill test to impress their superiors. If the PC rolls a Success, they can roll their best combat skill, if they Fail no roll is allowed, if they Botch, not only are they not allowed a roll, that PCís actions are clearly remembered by the leader and results in a two-step penalty to all Influence based skills with that leader


Fame Roll ††††††††††††††† Result

Critical Success †††††††† Gain the Good Name (minor) Trait

Success †††††††††††††††††††† Earn a one-step bonus to all Influence based skills with that leader

Failure ††††††††††††††††††††† Get a one-step penalty to all Influence based skills with that leader

Botch †††††††††††††††††††††† Receive a two-step penalty to all Influence based skills with that leader

Strategic Situation Modifiers

During any given battle, certain circumstances, good and bad, influence the effectiveness of an army. Terrain, weather, the nature of the enemy are all factors that can help or hinder a fighting force. All the modifiers are cumulative and the first of these modifiers is overall End Strength. Divide the larger ES by the lower to determine the attack ratio and Tactics bonus to the commander of the larger force.


Attack Ratio †††††††††††††††††††††††††††††††††† Tactics bonus

Even ††††††††††††††††††††††††††††††††††† †††††††††† No bonus

1.5 to 1.9 ††††††††††††††††††††††††††††††††††††††† Plus one-step

2.0 to 2.9 ††††††††††††††††††††††††††††††††††††††† Plus two-steps

3.0 to 3.9 ††††††††††††††††††††††††††††††††††††††† Plus three-steps

4.0 to 4.9 ††††††††††††††††††††††††††††††††††††††† Plus four-steps

5.0 to 5.9 ††††††††††††††††††††††††††††††††††††††† Plus five-steps

6.0 to 6.9 ††††††††††††††††††††††††††††††††††††††† Plus six-steps

7.0 to 7.9 ††††††††††††††††††††††††††††††††††††††† Plus seven-steps

8.0 or more †††††††††††††††††††††††††††††††††††† Plus eight-steps



For a side that is on the defense, if any, they will receive modifiers to the commanderís Tactics skill based on the quality of the defenses.


Tactical Modifiers

Down slope Attack: Minus two-step penalty

Attacker has cover: Minus one-step penalty

Gradual up slope Attack: Plus one-step

Steep up slope Attack: Plus two-steps

Narrow approach Attacker (pass, ford, or bridge): Plus two-steps to plus four-steps, based on how narrow is the passage.

Minor defensive works (abates, palisade, breastwork, trenches, or dry moat): Plus three-steps

Major defensive works (unwalled city or fort): Plus four-steps

Minor fortifications (walled city): Plus six-steps

Major fortifications (castle): Plus eight-steps


All defensive factors are additive. For instance, a walled city atop a gradual hill would count as plus five-steps.



Most armies fight as part of a balanced force and if they are not balanced it puts them at a disadvantage. If one side has a large superiority in a specific unit type (Infantry, Archer, or Artillery) the commander of that force receives a plus one-step bonus to their Tactics skill for each type of superiority they possess. To receive this bonus, one side has to have at least twice as many as the other side. If one side is completely lacking in one of the unit types the advantage is considered to be five to one.



Commanderís Opposed Roll

Once all modifiers to the two commanderís Tactics skills have been determined, the two sides roll to resolve the results of each Combat Round. The length of a Combat Round is deliberately vague with a timeframe of ten to thirty minutes as suits the GM. Whoever rolls higher wins that round and adds the difference between the results to that sideís Complex Action tally. How difference in how much the winnerís roll exceeds the loserís roll also determines how the contestantís forces are enduring the heat of battle.


Tactical Results


Exceeded by 0-2:†††††† Indecisive, battle continues unabated

Exceeded by 3-4: ††††† Slight victory, battle continues but winner gains an advantage over loser and a one-step bonus to Tactics skill for next roll

Exceeded by 5-6: ††††† Minor victory, battle continues but winner gains an advantage over loser and a two-step bonus to Tactics skill for next roll

Exceeded by 7+: †††††† Major victory, one side shaken and each unit of the losing side must succeed in an AVERAGE Morale Check or withdraw in good order, if it fails the roll, it routs



Exceeded by 0-2:†††††† Indecisive, defenders hold firmly even if they lost the roll.

Exceeded by 3-4: ††††† Slight victory and if defenders won the roll, they hold firm and gain a one-step bonus to Tactics skill for next roll. If attacker wins, the defenders manages to hold, but the attacker gains a one-step bonus to Tactics skill for next roll.

Exceeded by 5-6: ††††† Minor victory and if defenders won the roll, they hold firm and gain a two-step bonus to Tactics skill for next roll. If attacker wins, the defenders just barely manages to hold, giving the attacker a two-step bonus to Tactics skill for next roll.

Exceeded by 7+:††††††† Major victory and if the defender won they will throw the attackers back unless more than half its troops can make an AVERAGE Morale Check; if more than half fail, every unit that fails withdraws. If attacker wins, the defenders they will hold if more than half its troops can make an AVERAGE Morale Check; if more than half fail, all the units that fail will yield position. If unable to fall back, each unit will make a second AVERAGE Morale Check with a one-step bonus. The units that succeed continue to fight, making a gallant last stand, those that fail surrender.



As a battle progresses, the commanders add to their Complex Action tally. When that tally reaches the Threshold number for a unitís Morale Rating that unit becomes demoralized and their fighting skills suffer as a result. A demoralized unit loses ten percent of their UR (fractions rounded down).


Modifiers to Morale

Fighting a hereditary enemy adds a level to the Morale Rating.

Defending home territory adds a level to the Morale Rating.

Defeating an enemy in the same year adds a level to the Morale Rating, but losing to the enemy in the same year subtracts a level from the Morale Rating.



If enough goes wrong, an entire army can become disordered by combat. If more than half the units of an army have reached their Morale Rating threshold through the Complex Action tally or if Complex Action tally ever reaches INCREDIBLE (115) that army becomes Disordered. The results of Disorder are all remaining units withdraw, in good order if they can succeed in a HARD Morale Check. Units that fail this roll or have already reached their Morale Check level will rout, fleeing without thought of anything but escape.



During every Combat Round, each side will sustain casualties. For each point of difference in the Opposed Roll, the loser sustains d4% casualties, while the winner sustains 1% casualties per point of difference. Units wearing heavier armor sustain fewer casualties with Heavy units take 50% casualties, Medium 66%, and Light 75% with fractions rounded up. Disordered units take triple casualties


Post Battle Affects

One quarter of all casualties (rounded down) are killed and one quarter are permanently maimed. The rest are wounded to a lesser extent with half recovering in 2d6 weeks and half in 2d6 months. Modern medical treatment can cut healing time in half, but there must be one medic per ten wounded to get this advantage.


Artillery belongs to whoever held the field. In an indecisive battle where one side chooses to leave the field, half of lost artillery is recovered while the rest are destroyed.


Additional Fate Roll

All PCs that were on the side that lost the battle, make a second Fate roll, using the highest Danger modifier that PC used during the battle. If the PCís side became Disordered, there is a two-step penalty to skill for this roll.