Simpler Domains & Warbands. Part 4, Really Simple MASS COMBAT (Into the Odd version)

Once, there was Chainmail. Later, there was War Machine, and then Battlesystem. An Echo, Resounding has a battle system. For something lighter, there's Chris Kutalik's By this Axe or the even smaller-scale By this Poleaxe. Delta's Book of War. Etc., etc., etc. These (and quite a few other approaches) generally adopt some or all of the structure...and pace...of classic tabletop wargames. And then, of course, there are the myriad options for playing an 'actual' formal miniatures wargame, without any clear tie to an RPG.

Roight, me lads, form line...eh, wot's that?
We've no convenient mass combat rules? Aaarg, retreat!!!

None of those perfectly fit my current goals and needs as I think about weaving "mini-domain play" into my campaign. If my players are to lead little warbands of followers, clash with corsair crews or cultist gangs, and scatter enemies not just singly but by the dozen, then I'd like a way to manage it all that fits the following criteria:

+ ideally, the mass-combat rules will fit into a session's normal procedures of play as smoothly as possibly. The gold standard here would be integrated mass combat rules that do NOT form a separate sub-system. Yep, this can be done; read on!

+ similarly (or to stress a sub-point within point 1), if possible, tracking damage for gangs/warbands should use the same hp/harm system used to track damage for PCs - though I'm more willing to flex on this point, if necessary.

+ the rules should keep PCs' roles and fates clear and distinct; player characters don't just vanish into a mass of combatants, and PCs ideally should retain independent and critical jobs on the field of battle - they don't function just as bonuses to a larger unit's statline.

+ finally, in keeping with my love for minimalist design, I favor rules that aren't too taxing or complicated - they should work, and get outta the way!

Let's look at some options that I find interesting or appealing, and consider some observations on their strengths and weaknesses. I will also note, in passing, that recent blogoredditsphere conversations have also raised simple-mass-combat questions; for some other takes (and different recommendations) see, for example, here and here (look far down Norbert's post for mass combat guidance) and here [EDIT: and here, too!]. 

Now, for the stuff that I'm thinking about.

INTO THE ODD - DETACHMENT RULES 

Just as Chris M's Into the Odd (and now, Electric Bastionland) includes really nice, dirt-simple "Enterprise" rules that offer a very solid basis for one-brain-cell domain play (recently discussed here), Into the Odd (henceforth: ItO) also includes perfectly serviceable, simple but effective "Detachment" rules for handling combat with gangs, large crews, military units, giant monsters, etc.  If you aren't familiar with ItO, a few tips will be necessary to understand all this: damage automatically hits; instead of rolling to hit, then rolling for damage, you just roll straight to damage. Damage comes off HP without narratively doing 'damage' - but after 0 HP, you start taking "Critical Damage," which comes right off your Strength stat (usually), equates to actual bodily harm, and requires passing a STR save to stay in the fight). You die at 0 STR. 

To wit (taken from the free rules, available in the right margins here): 

DETACHMENTS cost 10 gold to start up, and cost a further d6 gold in upkeep each month, or else they revolt. ... Equipping a Detachment costs twenty times the individual item cost. Detachments start with 1d6 HP and advance in Experience Levels just as individuals do [which, in ItO, generally requires delving missions completed, not a gold-for-xp target]. 

In battle, an ItO Detachment is functionally identical to an individual character, with a few minor tweaks (this means a gang's stats fit on an index card, if not a postage stamp). 

A Detachment deals "Enhanced" damage against individuals (In ItO, this means it rolls 1d12 damage). Normally, an individual can't even attack a Detachment unless that individual's attack is "explosive or suitably large-scale" (so a dragon's breath weapon or a wizard's lightning bolts might toast your own gang of hirelings, but a PC with a halberd can't scratch a goblin warband; you either need to run away, or figure out some more creative way to affect the baddies). If you command a Detachment to do something risky, this "may require a WIL (Will) Save" by the player commanding that Detachment. 

"When a Detachment takes Critical Damage [i.e., 0 HP and damage coming off STR] they are broken and cannot act until rallied. At STR 0 the Detachment is wiped out. When half of a force is broken, the remaining Detachments must pass a WIL save or be routed. Hit Points and Ability Scores are recovered with Short and Long Rests just as with individuals. 

The newer version, Electric Bastionland, offers a few tweaks: Individual attacks against Detachments can cause damage, but they're Impaired (limited to 1d4); Detachment attacks vs. individuals do weapon +1d12, and have a 'Blast' tag - they affect all targets in an area. 

There are also a few other very short rules for ships, vehicles, structures, etc. Quite recently, one GM put together a very nice expanded model for using these rules in a pirate/nautical setting, quite worth checking out for play at sea or on land. 

Alright, let's discuss these. There are wonderful things here, but also a few points I'd like to change or expand. I love how smoothly these fit right into the (admittedly super-minimalist) rules for normal play in ItO; I like how the dirt-simple rules for financing Detachments work with the Enterprise rules (but don't require you to have an Enterprise to run a Detachment, or vice versa); and the fact that a Detachment can 'level up' in the same way as a PC (by running on adventures) is a very interesting design choice that pushes toward specific kinds of veteran units - rather than just throwing in more cash to make a specific, single unit stronger, you can always hire a new separate detachment, but individual detachments gain experience and Hit Points only by joining you, over time, on those terrifying ventures into the darkness below.

All that aside, as a general-purpose mass-combat/mini-domain-play system, I'd like to see a few changes. Past a certain point, Detachments seem a little limited by the binary way they are defined (something is either an Individual or a Detachment). No matter the size or experience of the Detachment, it still rolls the same amount of Damage. When two Detachments fight each other, only their Hit Points (and equipment, I suppose) differentiate between them. Equipping a Detachment with halberds always costs "Halberd cost x 20" no matter the size of the Detachment. Again, these are brilliantly simple  and will cover most of what anyone needs for a small gang, but I think there are enough edge cases to make some tweaks desirable.

HACKING THE ItO DETACHMENT FRAMEWORK

Several Powered by the Apocalypse (PbtA) systems that I have yet to discuss handle these issues in a nicely nuanced way; if I were running an ItO game right now, I think I'd borrow some of their ideas, and adjust Detachments like this: 

There are four classes of combatant, ranked by size: 

Individuals, 

Small Detachments, 

Medium Detachments, 

Large Detachments. 

Detachments can also be differentiated by their experience, which is reflected in their Hit Points, which only increase as they 'Level Up' (just as individuals do). Hiring/forming a detachment costs 1d6 for Small, 2d8 for Medium, and 3d10 for Large. 

In combat, individuals roll normally against other individuals. They roll Impaired damage against Detachments unless their attack has a Blast tag or other suitably extensive damage effect. Detachments roll Enhanced (1d12) damage against Individuals, and regular damage (by weapon type) against other detachments. 

When combatants of the same size-class fight, they roll damage as usual. When combatants of different size-classes fight, the larger combatant gains +1 Armor (damage reduction) and +1 bonus attack die for each step higher above their opponent's size. The attacker's hit dice are rolled together, including any bonus dice, but only the highest rolled result is used.

Examples: 

A Small Detachment of musketeers is exchanging fire with a Large Detachment of musketeers. Both Detachments are fairly green, and have 5 HP and 1 Armor. The Small Detachment rolls 1d8 damage, getting a 5, which is reduced by -3 (-2 because the other unit is two steps above them in size, so they gain 2 bonus armor atop their worn 1 Armor). Then the larger unit opens fire. They roll 3d8 (1d8 for their weapon attack, plus two bonus attack dice since they are two steps higher in size), getting a 1, 5, 8. Taking the highest result rolled, they inflict 8 damage, reduced only by the -1 Armor worn by the smaller gang. The smaller unit drops to 0 HP, -2 STR, and they rout (this is a pretty plausible outcome...).  

A more fortunate Small Detachment of spear-wielding goblins  (3 HP, 0 Armor) gang up on a lone but large sword-wielding barbarian (6 HP, 1 Armor). Not-Conan rushes the goblin gang, swinging his blade in great chopping arcs, but there are just so many of the vile things...he rolls an Impaired attack against the Detachment (1d4), inflicting 3 damage. The goblin gang is 1 step larger, however, so they gain 1 free Armor; they are left with 1 HP despite the barbarian's assault. Now they roll to attack, dealing Enhanced (1d12) damage to an individual, and rolling it twice because their +1 size step grants them an extra attack die. Results rolled are = 4, 8. They deal 8 damage, reduced by the Barbarian's 1 Armor, and now the barbarian is out of HP and taking Critical Damage...time to run away, perhaps...

...In which our hero helpfully shows how these rules
let individuals interact with Small Detachments. 

As these examples show, a few tweaks borrowed from Apocalypse World and its spin-offs can add a fair bit of depth and nuance to the simple procedures in Into the Odd, without breaking anything in ItO's more "OSR adjacent" system. 

YEAH, BUT WHAT IF I'M RUNNING NORMAL D&D...

Games using some version of D&D's normal combat rules (instead of the rules as modified specifically for Into the Odd) would need some tweaks to make these ideas work. There are too many possible variations to address comprehensively here, but I can offer a few suggestions:

+ ItO uses Armor as Damage Reduction. If your system doesn't do that, that's probably one key obstacle (though I suppose you could still use these rules with gang-size damage reduction on top of whatever else you're doing with AC). 

+ ItO dispenses with to-hit rolls. Between ItO, my own OD&D homebrew, and Dungeon World, I've gotten accustomed to playing with rules that speed up combat, so I suppose I can only shake my head sadly if you're really, really committed to rolling 3 on 1d20 all the time and prolonging combat. ;-) With the normal to-hit roll procedure, damage between detachments will be less common and less decisive, but that's just normal for to-hit-roll combat anyway. 

+ ItO hands out low Hit Points to PCs, and sticks with fairly low damage levels, compared to many other rulesets. A 20-HP PC is a very experienced, resilient character in ItO. 1d12 is a substantial damage roll. If your system typically involves higher HP or damage totals, I'd suggest increasing the Armor bonus from +1 per size-step to something a little higher, reflecting whatever is the typical range of damage rolled by a basic attack.

+ Along the same track, damage between size-levels needs to be adjusted if you don't want to use ItO's Impaired (1d4)/Enhanced (1d12) damage system. Without letting Detachments roll 1d12 vs individuals, you can also rewrite the hack above so that each size-step up gives the larger attacker +3 damage, or +1d6 extra damage, or something like that (this fits with some of the PbtA/Dungeon World mass combat ideas I still need to write about). 

USING TINY RULES TO GO BIG

"Ok, folks, your scouts' warning was clearly correct; they know you're coming. As you crest the last ridge above Hearthfire Village at the head of your army, you look across the sun-dappled settlement to see that Baron Argov's troops are already drawn up in their battle lines on the low hill opposite from you. You see their banners flapping in the breeze: it looks like Argov's got a Medium Detachment of pikemen holding his right flank, and a Large Detachment of bannerless (and no doubt miserable) peasant levies spread out across his left flank. In the center, you see the red banner of the Venomspike, and you know that the Small Detachment of armored orcs standing there has strength and skill that belies that unit's small size. And if your eyes aren't failing you, that tall figure in black armor at their side is Argov himself, with the foul necromancer in her dark robes behind him...

Now, how do you want to deploy your five detachments as you enter the valley?" 

I think these simple rules would work really well to game out a mass combat between small armies, in a way that still lets individual characters interact meaningfully with each other and with large units. 

Since my current campaign is using modified Dungeon World rules, however, there are a few other angles that I want to incorporate at my own table. Please stay tuned; next up, I hope to talk about some PbtA warband-combat and simple domain rules in their own right, as they add some further helpful ideas for enriching this kind of play.