Mass Combat

Overview

I have never found a set of mass combat rules in a D&D style game that I liked – but I never really knew why. However, sometime ago I saw a blog that explains it perfectly. The quote below sums it up.

“All of these games perpetuate the flaw that kept Chainmail from catching on in the first place: in order to play them, you have to stop playing D&D.

D&D is not a war game. All the design decisions that make a good war game lead to a bad D&D game, and vice versa.

-Because war games are played competitively, they must be fair. D&D campaigns can only achieve longevity when they are unfair in favor of the players.“

There is more to it, and I ‘sort of’ like the system he comes up with – but that doesn’t work all that well with my overall campaign rules. So I have come up with my own version.

Base Concept

I have read mythology and fantasy books for years, and whenever they describe wars, the action focusses on the heroic individuals and the actual battle take place in the background. The Siege of Troy, for example, focuses on Paris, Achilles, Ajax and other heroes – not on the battle. In Celtic myth Cu Chulain fights off a whole army almost single handled – but the stories deal with the small encounters rather than mass battles. In The Lord of the Rings, Tolkien focuses on the heroes at the Battle of the Black Gate – and I could go on.

It is that style of heroic battle that I want to portray in my mass combat rules. The battle is still there and becomes the backdrop for normally D&D style small group combats – with the PCs as the Armies’ heroes. Importantly the outcome of the PC encounters affects the morale of their army, and adds to their saves and combat rolls.

And that matches my experience as a re-enactor :] For years I have been a member of the Sealed Knot and, more recently, The Wimborne Militia re-enacting battles from 17th century Britain. I am never really aware of the overall state of the battle, apart from in the most general terms, because I am too busy fighting my own fight. The same was true when I was in command of a company or regiment involved in the battle – I was given a specific task, then relied on runners from a General to tell me what the overall position was, or to change my tasking.

I want to create the same sort of effect in my D&D game.

The Campaign Rules

My campaign rules are designed to support a long running game where the players can build up churches, businesses and strongholds – and even develop an independent state, if they want to – and these mass Combat rules need to work with those rules as well. That is particularly important at the moment as my primary campaign, runs on RPoL and can have fifteen or sixteen PCs split into three different adventuring parties.

Under those rules ‘Military Presence’ is defined by Defence Points. Each Defence point is, roughly, about a CR7 encounter (after very basic run-through combat) – and will form the basis of Army size/effectiveness calculations. To do this the size of the unit gets smaller and the toughness of the troops increases. So, perhaps, 10 guardsmen, 7 veterans, 5 light cavalry or 3 heavy cavalry, each make up 1dp of troops. And that makes sense to me, because all of those units have the same cost in the Campaign Rules (1bp) but if you want tougher troops you have to pay them more and buy them better equipment, so it balances out.

To find the total strength of the army I use the additive method found in the DM section of the PF rules. The table below is an extract.

Army CR Calculations

CRWeighting
165
2100
3135
4200
5265
6400
7535
8800
91070
101600
112130
123200
134270
146400
158530
1612800
1717100
1825600
1934100
2051200
2168300
22102400
23137000
24204800
25273000
26409600
27546000
28819200
291092000
301638400

Find the CR value of the unit in the left-hand side, then take the weighting from the right-hand side. Add the weightings together and then cross-reference that total to find the total CR of the Army.

So for example a very small army might consist of 4dp of guards and 3 DP of light cavalry

  • 1dp Guards = 535
  • 1dp Guards = 535
  • 1dp Guards = 535
  • 1dp Guards = 535
  • 1dp Lgt Cav = 535
  • 1dp Lgt Cav = 535
  • 1dp Lgt Cav = 535

Total = 3745

3745 = CR12 army.

For that example, I could just as easily have said 535* 7 = 3475 and got the same result.

This all assumes that the Army has a suitable NPC command structure in place, which should be more or less in place from their other functions in the game world.

However, this system allows us to be a bit more flexible. Perhaps a Cleric, Wizard and Ranger also live in town, and they come along to support the army …

  • Army = 3475
  • L4 Cleric = 135
  • L7 Wizard = 400
  • L6 Ranger = 265

Total = 4075 – or a CR13 army.

Note: Characters with at least one level in a PC or Prestige Class.

Example

Midmarch has an army worth 44 defence points, assuming that every unit musters as requested – that gives an Army strength of 23,540 – or a CR 17 army. However, there are a number of NPCs or inactive PCs who come along in support of the army.

  • Henry (Aristo/Scion) CR6 – 400
  • Rikka (Magus) CR5 – 265
  • El (Fighter) CR3 – 135
  • Abbess Beatrix (Cleric) CR3 – 135

Bringing the total strength up to 24,475 – which is still a CR17 army, but it doesn’t need much (perhaps the Roths) to push it up to CR 18.

It makes combining armies straight forward as well. For example House Khavortorov have 15dp (8025) of normal troops and supporters worth another 1465 – giving an army strength of 9,490 or a CR15 army.

Should Midmarch and Khavortorov join up to fight together – their total is 24,475+9,490 = 33,965. Or a CR 18 army. Again it doesn’t need much (just a L4 PC) to tip it over to a CR 19 army.

Making it work.

The battle ebbs and flows around the battlefield, often in sight of the heroic PCs battle. At the end of each combat round one of the PCs rolls for their army, DM rolls for the enemy. Opposed D20 roll – modified by the Army CR and mods awarded from the PC battle. Keep a total of Victory Points.

Army wins by 15 or moreDominant win+3 Victory points
Army wins by 10 or moreWin+2 Victory Points
Army wins by 5 or moreWinning Draw+1 Victory Point
 DrawNo Change
Army loses by 5 or moreLosing DrawNo Change
Army loses by 10 or moreLose-1 Victory point
Army loses by 15 or moreHeavy loss-2 Victory points
PCs get the better of the round +1 morale modifier to Army combat roll
PCs clearly winning +2 morale modifier to Army combat roll
PCs win Heroic Combat +5 morale modifier to Army combat roll, and
+5 Victory points.

The battle ends at the same time as the PCs Heroic Combat.

Victory Conditions

If an army ever reaches -25 Victory Points, it routs and runs away. It might be reformed later, but it suffers a -4cr depletion penalty until it can get back to its barracks and recruit new soldiers. Getting a routed army to reform is an RP challenge for the PCs. A routing army may be pursued by Heroes from the other side, but the victorious army does not chase them.

If no-one routs – then both sides retreat to their pre-battle formation when the PC heroic combat finishes. Any army who finishes the day with 1+ Victory Points – suffers a -1cr depletion penalty until it can get back to its barracks and recruit new soldiers. Any army who finishes the day with 0- Victory Points – suffers a -2cr depletion penalty until it can get back to its barracks and recruit new soldiers.

Whether the armies reform and fight again next day is down to the commanders on both sides. Either commander can choose to retire and concede the ground – if both choose to stand, the battle starts again the next day (with the cr penalties applied)

Why do it that way? Even a victorious army loses soldiers unless they are re-enforced – and that is hard to do with limited communications and really slow transport. But just as importantly, it means even Victorious leaders have to think about their army strength – especially if they think they need to take on a different army later.

Sieges

Sieges have always been more difficult that open battles, and even taking buildings with light fortification or defence is more difficult than taking, or burning, civilian properties. This is because there are more combat trained people about, that can fill in when required. Under the Campaign rules there are auxiliaries and militia – and then there are all those guys who are too old to go off on active duty. However, they can fire crossbows for the walls, chuck rocks over the battlements, pour hot stuff through murder holes or poke spears at anyone who comes close. So …

  • If the troops are at home (ie not out as part of an army) Defence Point Value for every fortified building, villages with palisades, or towns/cities with walls is doubled.
  • If the troops are away, with the army, the buildings are defended by those people left behind – so defence points still count (but at normal value) if the building or settlement is besieged.

The problem arises when you have a city like Tusk. Three districts are inside the walls – and benefit from defence – but another three are outside the walls and there is nothing to stop a marauding army destroying those districts – when the army is away from home.

Posted in House Rules, World Building.

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