Work in progress: Large Scale Battle

Hey, I'm working on some rules for large scale battles in Ars Magica. Now some might ask why I need that in a game that isn't so much focused on mundane politics? Well, I'm making planning to use a regio that has trapped a piece of time in it, with a battle being "replayed" over and over until someone (the Magi) comes in and solves some arcane riddle. They must also take command of some of the forces in this regio. So I though I needed some rules for large scale battles. And since I couldn't sleep anyway, I wrote them down. Here's what I have so far. I have not playtested it yet, but I'd be happy for some comments and maybe ideas:


Ars Magica

These rules, for large scale battles in Ars Magica, use a system very similar to that of regular combat. The large scale battle rules are meant to be abstract enough to focus on the narrative descriptions of the situation, and still put the characters in charge if the situation warrants it. This system is not meant to track the actual number of soldiers in units, but rather their general strength and effectivity.

(Note: This is work in progress, and it's still very basic. I will add tactical options later, such as rules for charges, commanders and morale. But this is the general idea, and it's meant to closely follow the rules in the Ars Magica core book for individual combat.)

Soldiers of similar type are gathered into units, and units together make an army. In a round of large scale battle, each unit behaves very similar to an individual in regular combat. Here are the basics:

A unit has the following statistics:
Attack: This rating equals the average Attack Rating for an individual soldier in the unit, modified by the unit's current Force rating.

Defense: This rating equals the average Defense Rating for an individual solider in the unit, modified by the unit's current Force rating.

Damage: This works exactly as in regular combat.

Soak: This works exactly as in regular combat. However, see Casualties

Force: This rating can be negative or positive, and comes from the number of men in a unit. This rating is directly added to or subtracted from the Attack and Defense ratings of the unit. The Force ratings are: -4 (under 100 soldiers), -3 (between 100 and 200 soldiers), -2 (from 200 to 300 soldiers), -1 (from 300 to 400 soldiers), 0 (from 400 to 500 soldiers), +1 (from 500 to 600 soldiers), +2 (from 600 to 700 soldiers), +3 (from 700 to 800 soldiers) and so on...

Casualties: This roughly equals «wounds» a unit takes. There are five categores, and these are Minor Casualties, Medium Casualties, Heavy Casualties, Routs and Destroyed. Each of these gives a penalty to the unit's Attack and Defense Ratings. Minor gives -1, Medium gives -3 and Heavy gives -5. Rout means that the unit takes enough casualties to disbanded, with the soldiers fleeing for their lives. Bravery rolls for certain characters can be used here to avoid that, but in any case, the unit is no more. Destroyed means that the entire unit is captured or killed. Personal combat can be used here for characters wishing to make a last stand.

Here's how it works:
1.Initiative: In large scale battle, rounds are longer, roughly 20-30 minutes each, and Initiative is not rolled. However, in some situations, rolls on Tactics and similar abilites can be used to gain an advantage.

2.Movement: The battle is set up as two opposing armies face each other, and is measured for a unit in relation to the enemy. Each unit is considered to be at one of four ranges in each given combat round. These are Near, Medium, Long and Far. Near range is when close combat is joined, but thrown weapons can also be used at this range. In any case, combat at this range is rolled exactly as melee combat. Medium range is when units are not in melee, but can shoot with regular missile weapons such as bows and crossbows, but not thrown weapons. Far range is used for catapults and other siege weapons, and some bows, such as English Longbows. Far means that the units are out of range to any missile weapon. Each unit can move each round. Infantry can move forward or backward one range, for instance, from Medium to Near. Cavalry can move two ranges in one round.

3.Combat: All the units fighting in the current round rolls one stress dice and adds both Attack Rating and Defense Rating seperatly, making two totals. Add the unit's current Force Rating to these totals, then compare Attack and Defense Ratings for units in combat with eachother. Attack Totals above Defense Totals make Attack Advantages, which are added to Damage Totals. Do this for all the units in combat before going to the next step.

4.Damage: Calculate damage exactly as in regular combat. Then subtract the Soak, and compare the remaining damage to the table on page 179 in the Ars Magica main rulebook. Use the Damage Table, but exchange Size for Force Rating and the Wound Categories (Light, Medium and so on...) becomes Casualty Categories.

That's the basics. I will add more later, like unit commanders and how they can use Confidence etc.

Here's an example:

A group of 120 Templar Knights (using the Templar Companion from RoP: The Divine) face a unit of 400 footmen (Standard Soldier from the core book) on the field of battle. They both start at Far Range. First round, the Templars spur their horses and move two categories into Medium Range. The footmen are can now move one category, into Near Range, getting them into melee. However, they choose to brace for the charge (I will write mote on specific tactics like this later) and hold their ground.
Next round, the Templars continue their charge, and ride into the unit of footmen. Battle is joined, and a stress die is rolled for both units. The Templars get a 7 and the footmen a 5. The Templars' total Attack and Defense are, with a Force rating of -3, 16 (7+12-3) and 12 (7+8-3). The footmen get, with their Force rating of 0, 17 (12+5+0) and 16 (11+5+0). Ratings are compared, and the Templars gain a hit, but with no Attack Advantage. The footmen also hit, and with an Attack Advantage of 5. Now damage is calculated. The Templars have a Soak of +10, making the total damage 2. Because of the poor attack advantage, and the footmens' Soak of +8, they take no meaningful damage. However, the Templars, take Minor Casualties from this round of combat, giving them -1 on their Attack and Defense for the rest of the battle.

Your rules may cause you problems when pitting units of different numbers - especially in the several hundreds - against each other. Then often one unit would engage only part of another - - like the Templars in your example charging through the center of your footsoldiers and scattering them.
That's why tactics games often use 'base size' rules.
But as long as you make sure that your units' front lengths are comparable, this might not hamper you in your projected battle.

Your movement rules will not work within your 20-30 minute rounds: the movement of all your units is far too slow.
When correcting the rules, you might consider that, compared to the knightly charge or the maneuvers of arab cavalry, moving large units of medieval footsoldiers over the battlefield took still lots of time, and hence further diferentiate movement rates.

Kind regards,


Good points, but not impossible to work around. The rules are meant to be very abstract, but I will add details on cavalry charges, morale and formation. But again, it's meant to be narrative, not tactical.
What length of time do you think the rounds should be?

But what do you think of the basic idea? :slight_smile:


I'm not sure I follow the reason for negative numbers..

So a group of 100 versus a group of 100, both would be at a disadvantage?
Why not just a +1 per (say) each group of 100?

What about creature size?

One group is a mixed group of giants, dragons and faeries...
How does that change things?
Just a thought...

How about extending the rules for Group combat in ArM5? I think these can serve as a good basis, but I'll have to think about it.

Force modifies the Attack and Defense by (-4+1 per 100 men). Why? I don't understand the reasoning.

These rules seem pretty 'simulationist'. Along these lines, it might be worth thinking on what an aggregate of ArM5 combatants will do. I don't really see how your Force accomplishes this.
[size=75]Simulationism is very difficult. A massive ArM5 combat simulator might be interesting to see in work, to give an idea of what the ramifications of the mechanics are.[/size]
Realistically, ratios are more important than pure numbers. Consider a force of 100 knights facing a force of 200 knights; under your system, the 100 knights will be at a 3-points disadvantage - a slight disadvantage. In reality, barring exceptional circumstances or tactics on both sides, the 200-strong force will rout the opponents with little casualties.

In general, ArM is better suited I think to "guesstimate" combats, with the war serving as background progressing by SG fiat. I think a system like that presented in Heroes of Battle, where PCs are faced with tactical missions to accumulate Victory Points and change the flow-chart of the battle's progress, may prove useful. I'll have to re-read it and try to transport the ideas to ArM.

Given the extreme high power of magi, I would just respond to the PCs magic by ear - magic is too powerful and diverse to insert into the rules.

I think that this approach could be made to work. However, let me propose a very different alternative, stressing leadership.

Introduce a new ability, Tactics. Define a flowchart for combat with different phases of the battle. In the first phase, the armies are maneuvering for overall position; that is, they're determining where the battle will take place. Each leader makes a roll modified by his Tactics ability, the size of his force (smaller = faster), and the proportions of his force that are professional infantry, peasants, and cavalry. The winner of the roll has a bonus for the forthcoming battle based on his ability to position his army better. (The loser might just march off the field if the bonus turns out badly; alternately, the winner might, if his bonus is high enough, evade combat or force his opponent to fight even if he doesn't want to.)

Then the battle properly speaking begins. Using the leader's Tactics score, the positional advantages determined before the battle, the ratio of the sizes of the forces, their ratios of professionals to peasants and cavalry to infantry and so forth, and, in the first rounds, bonuses for archers and artillery, the leaders roll off to determine how much damage they've done to the opposing force. That affects ratios of sizes and types of troops, thus altering the bonuses for the next roll. The leaders' Leadership becomes relevant when casualties begin to pile up: the leaders must roll their Leaderships against an Ease Factor determined by their sides' casualties so far, and in this latest round, to prevent an overall route. (This makes Leadership a little more useful than it is in the rules as written. For consider that someone like Alexander the Great could only command an army of, say, ten men in the rules as written.)

The work to be done to make this idea work consists in determining the relevant ratios and bonuses to apply; in the absence of any such figures, your variant is obviously the better worked-out.

A third alternative is to just take over a set of miniatures rules and play a different game. There used to be miniatures rules, called Battlesystem, for D&D. It might be more fun to just come up with a way to integrate magic and magical beings into a set of miniatures rules for medieval battles.

That's what I would recommend. Pick a simple (or, at your option, complex) wargame, and let the magi do what they can to the troops' strength, vulnerability, appearance, speed morale, etc.

DnD Minis might be a good choice.
(despite the already great wealth of WotC)

Some minis have a Commander Rating.
The FLGS we game at has a pool of figures available ,
and some people will happily lend figures on site.

HARN also has a mass battle system that might be useable.

Unless you wish to rework your Combat and Damage rules from the ground up, you probably should roughly keep the timing of ArM5 combat rounds: so maybe double the length of such a round to 12 seconds.

It's a natural extension of the ArM5 rules, hence intuitive. I don't quite see yet how to make it generate appropriate results from some commanding characters' input without a lot of handwaving.

Kind regards,


Groups of groups of groups of groups?

Well, the main point is to make it simple to use, not very detailed. Using a complex wargame would not serve the purpose, at least not for my campaign. The main idea was to make it play as fast as regular combat.

But changing the Force bonus to be based on ratio would work, I think. I think I'll do that.

The idea that the unit takes "wounds" which gives penalties to attack and defense, is that these are losses, and the more penalties the unit takes, the greater the chance is that it will rout or become destroyed.

Another idea I've been working on is to have a Tactics ability, and for each level of that ability, the commander of that unit know another special tactic, granting bonuses in certain situation. These could be chosen from a list, almost in the same manner as spell specialization.

Keep the ideas coming, but remember again that the main point is to make play it simple and fast. I don't want a 10 page set of wargame rules here. It should be based on the Ars Magica rules, quick and easy to use in a game that focuses on magic.


How are you planning to integrate Magic use?
Any spells with sight range , especially Weather Control type , would have a significant effect on most battles.
Or is this designed as a "problem cannot be solved by direct application of magic" scenario?

Another thought is ReCo spells.
These would be able to shift units around quickly and efficiently.
As ArM 05 makes no reference to movement rates ,
i am not sure how to apply this for mass combat.

You might want to check out the (simple) wargame Hannibal. Battles are resolved by play of cards, each card indicating an attack or defense formation. Some styles of attack work great against some styles of defense and contrariwise. I only played the game once, but it seemed to work pretty well.

With regards to magic use, I'm still working on that, but it will be quite straight forward. Maybe some new spell guidelines, but these rules are supposed to mesh easily with the regular combat rules, so the Storyguide can quickly switch between them, by "zooming" into the battle, maybe having some fights in regular og group combat.


Large battles where covered in Ordo Nobilis. It used cavalry as the base (1 knight plus support), and all others were judged by that, (100 levies, 25 men-at-arms). Bonus's based on terrain, ratio by which outnumbering, etc. Dice roll of Int + Leadership (actually strategy, but that was 4th edition) + bonus's. Each side inflicted it's total x3% to the enemy. The higher roll won the battle, and also inflicted difference x10% as the enemy was routed. Each side judged how it took it's own losses (to levies, knights, etc).
Didn't cover magic though :frowning:.
That's a messy looking block of text, hope it makes sense. Those rules might still be useful in 5th edition, they seem abstract enough that they could still be used.

Well, I really want a system with several battle rounds, but still keep it simple, not one where the whole battle is decided in one roll. Still working on my own system, and I feel it's simple enough, but still gives room for special tactics and such..



I'm not sure is it already so well known and discussed that noone mentiones it, but few years ago, in times of 4th Edition, I googled out Mass Combat for Ars Magica Article and found it quite interesting.
Never got a chance to fully playtest that system, but precalculations as well as example given in article look promising, at least as a good start for your own work.

Check out the Giant Pricelist link from the Ars Magica page
A certain John Nephew is listed as one of the contributors.
Timothy Ferguson is also named.
Some other names may be familiar to those on the Berk-list.

The possibly confusing thing about the price table is putting the letter code before the number.
d20 and similar could be read as a dice code , not 20d (pennies).

Excellent! This looks exactly like the sort of thing I'm trying to make. Well, it seems I don't have to make it, then. :slight_smile: