As a GM or a player, the question to ask is - what kind of combat are we doing? Do the participants plan to raid the enemy? Is it small scale? Large scale?
A GM is required to carefully note down all results of rolls separately from the scene, ideally in a spreadsheet. In this way, it becomes much easier to keep track of who won which roll / which combats, applying modifiers as necessary to subsequent rounds.
Modifiers are optional, though encouraged – one can strip them out of the system and still have it work properly; however, using at least the modifiers for the three planning rolls is recommended.
Planning Phase
The first thing that is to be done in the planning phase is that the commanders will give a brief summary of their intent – whether they wish to attack the enemy head on, draw them into a particular piece of terrain, block their advance completely, conduct a fighting withdrawal etc… Then, the planning rolls are made.
The planning rolls are 3x contested rolls of Command. They consist of:
Deployment check
The deployment roll represents a general's skill at putting his soldiers where they need to be, and includes elements of supply and logistics.
Players can receive bonuses on their roll if – they have better scouting than enemy, have a high mobility, know the local area better, have better supply lines, have fresher soldiers.
Victory in this roll gives the winning side the ability to watch the enemy's deployment and then deploy their own forces accordingly.
Tactics check
The tactics roll represents a general's skill at developing a plan for once battle commences and having his soldiers follow that plan.
Players can receive bonuses on their roll if – they have soldiers with better training and cohesion than the enemy (represented by a higher average of assault & skirmish skills), are significantly better commanders than the enemy, have better sub-commanders than the enemy, if they come up with a good plan
Victory in this roll gives the winning side a bonus to assault and skirmish rolls.
Leadership check
The leadership roll represents a general's skill at inspiring his commanders and soldiers to fight
Players can receive bonuses on their roll if – their soldiers have a higher average morale than the enemy, they are fighting to defend or take back their homes, they have strong political or religious motivation, they have significantly more opportunity for profit than the enemy (in the form of plunder for bannermen or direct cash for mercenaries)
Victory in this roll gives the winning side a bonus to morale checks.
Deployment
Whether it's using the roll20 website's battle maps (where practical, instructions to follow) or simply in game poses, as a GM, make sure that the geographical area in which the battle takes place is both well thought out and clearly communicated to players. Nothing makes decisions more difficult to make and a battle more frustrating than not being able to visualise what is going on around one's character and army.
Each army will group their units into five battalions (also called units). Typically, these battalions will be left, centre, right, cavalry and reserve (often times called the missile line, though not always). The limit to five battalions per side, while not absolute or concrete, makes management of the battle easier and more enjoyable for both players and GMs. A battalion can be of one single troop type or a mix of different troop types – in this case, one troop type will typically be the main unit, with the auxiliary troops increasing or decreasing the main unit's abilities as per their traits.
Rolls within the battle occur between individual battalions not entire armies. It's in this way that sub-commanders, those controlling battalions, make their mark; their successes and failures against their enemy counterparts affect and are affected by the battle around them, in the form of modifiers. Generally, sub-commanders will roll against enemy sub-commanders.
PCs engaged in combat will also affect the course of the battle significantly more than NPCs, as well as modifiers applied to the rolls between units. Individuals, whether sub-commanders or PCs, are the heroes of the battle; they will have a disproportionate effect on its outcome.
A note – with the Roll20 system, manoeuvre is easy to demonstrate and makes for good roleplaying. If the GM decides not to go with Roll20, however, then obviously manoeuvre is harder to demonstrate and the battles will necessarily be simpler.
Once the units have been deployed onto the field, combat can commence.
Overview & Types of Engagement
The GM will set a rough minimum distance between the two forces before they join battle, in order to make manoeuvring possible, although this is terrain dependant. Each unit has a mobility skill which determines how many hexes it can move. As the two armies move towards each other, they will begin to initiate combat. Combat takes place in three different engagement types: skirmish, assault and retreat.
Skirmish
Combat between two units that takes place mostly at range. It may involve the exchange of missiles or quick melee raids that form and break apart very quickly. This obviously is the favoured combat of most missile troops, and tends to be the primary engagement for light troops and cavalry, due to their extensive mobility which enables them to move fluidly. Heavier units can sometimes be adequate skirmishers, particularly those trained to operate in looser formation. Units with any kind of ranged weapon may engage from distance, while melee units can skirmish when adjascent to their enemies.
Aptitude in this type of engagement is governed by the unit's skirmish skill, and their range in the case of ranged combat.
Assault
Combat between two units that takes place in a close quarters melee. It is favoured by units trained to operate in close order formation and heavy cavalry. The assault is typically the deciding factor in a battle.
Aptitude in this type of engagement is governed by the unit's assault skill.
Retreat
A retreat is where one unit is leaving the immediate battle, either to manoeuvre on the field, to return to the reserves or fall back to a place of safety. A retreat may be orderly (a withdrawal) or disorderly (a rout). Orderly withdrawals are the mark of disciplined units and very difficult to execute. Routs, on the other hand, are often where the majority of the casualties are inflicted during battle, as when soldiers turn their backs to the enemy they are extremely vulnerable.
Success in withdrawing will be covered later, but involves the unit's mobility skill.
Combat
As outlined, rolls in combat occur between units, which square off in one of the three engagement types: skirmish, assault or retreat. Combat typically starts off at skirmish range, although this can be bypassed if both commanders simply charge into the assault right away.
Turns & Elapsed IC Time
Each turn of mass combat encompasses three turns of FS3 combat, if PCs are engaged in active FS3 fighting. The length of the mass combat turns depends on the particular scene and the GM running it; however, they ordinarily represent 30 minutes of fighting time. Fighting
Joining battle
Each battle round, the two sides decide which type of the three engagements they wish to join. There may be disagreements between what both sides which to do; for instance, one side might wish to skirmish while the other wishes to assault. In this case, the commanders will make a contested Command + Mobility roll. The winner decides what type of engagement will be fought.
Combat
The appropriate skill for the engagement will be rolled between both commanders. A contested Command + Skirmish or Command + Assault plus or minus modifiers determines who wins the round.
- Players can receive bonuses on their roll if – they have a unit which is significantly larger than the enemy, sub-commanders roll successfully or PC fighters engaging in combat defeat their enemies, the Army's commander is leading from the front, they have unit traits which come into play for the particular situation, they're flanking the enemy or have an ally who is flanking the enemy, or they won the tactics roll in the planning phase.
Morale
When a unit loses a round of combat, one of their allies routs or they are hit with artillery fire, they must make a morale check, although certain very well disciplined units waive this requirement on their first loss in an engagement. The morale check consists of a Presence + Morale skill, with any pertinent modifiers added on.
- Players may receive bonuses on their roll if – they are renowned, trust commanders, have a commander who won the leadership roll in the planning phase, a sub-commander has won his morale roll, they are fighting to defend or take back their homes or they have strong political or religious motivation.
- Players may receive penalties on their roll if – there are a number of broken or retreating allied units, a sub-commander has failed a morale check, or one of their heroes (PCs, usually) has fallen on the field.
A roll of success or below constitutes a failure, which puts the unit into shaken mode . Shaken units do not take penalties but they are in danger of breaking. The second time a battalion fails a morale check it breaks and will rout, making a disorderly retreat.
Retreats – Withdrawals and Routs
A unit can make an orderly retreat from battle by making a contested Command + Mobility roll. If the unit trying to withdraw wins the roll, contact is broken and they are able to manoeuvre. If they fail, however, they remain in combat.
- Players can receive bonuses on their roll if – terrain is favourable, their commander won the tactics roll in the planning phase.
If a unit fails two morale checks, it will rout and their enemies may decide to pursue them. The pursuing side rolls Command + Skirmish while the routing side rolls Command + Mobility. The rout is typically the most dangerous time for a unit and if it the pursuing side wins, they will do serious damage.
Rallying
A shaken unit can be rallied as long as they have just won a combat roll or are in safety. The commander declares intentions and voluntarily rolls Presence + Morale. A success takes them out of shaken mode, while if the roll is failed, they will remain shaken.
If a routing unit escapes pursuit, however, it can possibly be rallied by the commander. A roll of Presence + Morale is taken. Success puts the unit into shaken mode, while failure causes it to continue routing and withdrawing out of battle.
Note - Mercenary units have a special rule called 'Cost-Benefit Analysis.' They have a lower Morale trait than many other units, but instead of routing when they fail their second Morale Check they make a fighting withdrawal in an orderly fashion, first manoeuvring from Assault to Skirmish and then Skirmish to Retreat. A third morale check loss, however, will cause them to rout as with any other unit.
Casualties & Prisoners
Casualty calculations are done for each individual battalion, and consolidated from three different figures.
- The first number is based off of the "damage" each battalion took from , calculated on the basis of combat roll results. These are: 2% for a marginal loss, 5% for a solid loss, 10% for a crushing loss.
- The second number is based off of how many rounds of combat each unit fought. A unit fighting two other battalions at once counts as having fought 2 rounds. Similarly, being under missile barrage causes a round of combat, even if the unit in question did not reply. Each round of combat fought causes 2% casualties automatically, which represents the fact that even if a unit is winning against the enemy, it will still incur casualties.
- The third number is anything added on from post-combat action. This includes routing (10% immediately), withdrawing under pursuit (10% per round) and routing under pursuit (20% per round). The amount of casualties taken varies depending on how many rounds the withdrawing/routing units were harried for.
After Battle - Casualty levels and their effects
When casualties are calculated, an average of 30% of them are fatalities or maiming wounds, which take troops inuring them out of the line permanently. This number can change up or down, depending on the proficiency of the army's healers, the circumstances of its withdrawal as well as their troops' equipment; better armour generally means less men killed.
Battalions that have taken significant casualties may be assigned negative modifiers by GMs to roll with until they’ve been reconstituted. This means that after a battle, reorganising the army and catching one’s breath is important.
Prisoners
Prisoners are typically taken out of enemy wounded figures in the case of an enemy withdrawal or defeat and sometimes out of healthy soldiers if the situation dictates.
In RP terms, prisoners are at the discretion of the commander, who generally sets the prisoner taking policy before the two armies meet. Soldiers in the heat of battle, however, do not always listen to a commander's orders offering quarter. On the other hand, they may relent from an order of “no quarter” depending on circumstances, at least while they are in combat.