D&D 5E Help me make a mass combat system that does what I want

[Xeviat]

Did you ever check out the 3.x Miniatures Handbook? That was the point (just prior to 3.5) where WotC decided to go full-bore on making D&D a tabletop boardgame instead of just an RPG, and it had most do the features you describe. It's not 5e, obviously, but could be easily adapted.

This, and also Heroes of Battle has some stuff.

Treating units of soldiers as a big creature until they disperse is easiest, I think. 3E did this with swarms, and people extrapolated that to mobs and war units.

3E translates to 5E rather easily once you change the attack, skill, and save bonuses.

 

[Spohedus]

Going a different, but not wrong direction.....take a look at the Battle of Brindol design from Red Hand of Doom. I would argue that regardless of what you are trying to achieve, that design is a better experience for the players and easier to run for the DM. Win-Win, and Epic Sauce all around.

 

[Orban Sirgen]

I would recommend taking a look at the 3.5 Heroes of Battle... (Not to be confused with Tome of Battle, which is the martial arts one...) It has a lot of stuff about mass combat, so it should be helpful and shouldn't be too difficult to convert to 5e...

 

[UngeheuerLich]

My suggestion is to add an idea from Pathfinder: the troop monster subtype. It is like swarn but for humanoid and bigger creatures.

You can find it in the SRD.

Without reading the pathfinder rules,
I guess that would be the easiest way to handle it.

You can have troops of 4 or so, and with enough damage, you kill more than one of them at once:
Cleave, pierce through, several small stabs can be used to describe to killing them,as well as killing one and the others running away or cowering and being out of combat.
If you need more enemies, just use more troops.
I liked the 4e Idea that area attacks dealt double damage vs swarms. You probaly could add that. But usung ordinary 5e swarms would work too.

 

[overgeeked]

Take the commoner, guard, and noble stat blocks. Equip them to whatever the standard would be for the unit as a whole. Give the unit as a whole hit points equal to the number of soldiers in it. Heavy infantry and heavy cavalry will have higher AC, but you might want to give each soldier 2 hp, representing their extra training, skill, and experience. Basically hit points go back to the old meaning of tracking how many hits to kill one soldier.

Use the mob rules from the DMG to determine how many attackers to score one hit. But each hit is a point of damage and thus one dead regular soldier. Abstract things like rank & file and frontage. Definitely use morale.

Change the turn length to ten minutes. Change the scale of distance from 5ft squares to 500ft squares. This keeps the movement in squares the same number. So a human can move 30ft / 6 squares in a 6-second round at a 5ft square scale or 3000ft / 6 squares in a 10-minute round at a 500ft square scale.

Otherwise it can run the same. Double move. Defensive stance. Etc.

To use big monsters, just treat them basically as normal. With mob rules, most will auto hit but roll damage. Each 1-2 points of damage is a dead soldier, depending on type. An adult Silver Dragon breathing cold for 13d8 is properly scary again. Like it should be.

So a peasant soldier with a spear, shield, and studded leather is going to have AC14, +0 to-hit, and 1 hp. 30ft move. Put 1000 of them into a unit and the unit has 1000 hp. Light infantry.

Or a knight in plate with a shield and lance on a warhorse is going to have AC20, +1 to-hit, and 2 hp. 60ft move. Likely the mounted combat feat, which would be the equivalent to an extra +5 to-hit. Put 500 of them into a unit and the unit has 1000 hp. Heavy cavalry.

That cavalry unit wins initiative and charges that spearman unit. The heavy cavalry inflicts 250 hits. The infantry is reduced to 750 hp (and men) and counterattacks for 37 hits, reducing the cavalry to 963 hp and 482 men. The cavalry breaks off and moves to prepare for a second charge.

The dragon swoops in and breathes cold on the infantry killing 60 before flying off.

If you want it more gamey, you could use a d20 for hits, but make it a scale, like: nat 1 = 1/4 hits; miss = 1/2 hits; hit = full hits; nat 20 = 1 1/2 hits.

ETA: Or just use the stat blocks as is with the mob rules and use the listed average hp and damage. A goblin has 7 hp and deals 5 damage per hit. A unit of 100 goblin soldiers has 700 hp and reduces its attacks by one for every 7 damage it takes.

 

[babi_gog]

Would suggest War Law, from Iron Crown, but it's out of print. However it does a good job of sorting these things out.

 

[Benjamin Olson]

I think the basic problem with D&D mass combat is that the game is not designed with mass combat in mind and players do not build characters towards success in mass combat. Mass combat systems end up being a minigame that either ignores your characters' abilities or else repurpose a handful of them and semi-randomly reward characters for having features that the mass combat designer can think of reasons to make useful for mass combat. There's nothing wrong with a minigame per se, the trouble is that by the nature of what mass combat represents it is often a very consequential thing to have be decided by minigame the players aren't used to and haven't developed their characters towards. The alternative of not actually doing the mass combat and just using the big battle, siege, etc. as the backdrop for some decisive skirmishes by the PCs ends up usually being the better call because it keeps the important action within the normal scope of gameplay.

I don't think its impossible to have satisfying mass combat in a tabletop rpg that looks very much like Dungeons and Dragons. But the rules would have to be baked into the system and, more importantly, it would have to be a regular aspect of play that players build characters towards being effective at. A 5e variant with good mass combat would need spells, feats, skills, subclasses, etc. geared towards making characters more effective and providing interesting and creative options in the additional mass combat pillar of play, and campaigns would have to involve enough mass combat that people invested their character resources in all that.

 

[Sword of Spirit]

I think the basic problem with D&D mass combat is that the game is not designed with mass combat in mind and players do not build characters towards success in mass combat. Mass combat systems end up being a minigame that either ignores your characters' abilities or else repurpose a handful of them and semi-randomly reward characters for having features that the mass combat designer can think of reasons to make useful for mass combat. There's nothing wrong with a minigame per se, the trouble is that by the nature of what mass combat represents it is often a very consequential thing to have be decided by minigame the players aren't used to and haven't developed their characters towards. The alternative of not actually doing the mass combat and just using the big battle, siege, etc. as the backdrop for some decisive skirmishes by the PCs ends up usually being the better call because it keeps the important action within the normal scope of gameplay.

I don't think its impossible to have satisfying mass combat in a tabletop rpg that looks very much like Dungeons and Dragons. But the rules would have to be baked into the system and, more importantly, it would have to be a regular aspect of play that players build characters towards being effective at. A 5e variant with good mass combat would need spells, feats, skills, subclasses, etc. geared towards making characters more effective and providing interesting and creative options in the additional mass combat pillar of play, and campaigns would have to involve enough mass combat that people invested their character resources in all that.

You know, that's a really good point about character stats being mostly irrelevant (or only some characters' being relevant,) in mass combat.

I have no problem with it as a minigame. The point of it for me is as a way to allow players the option to do something different by taking control of mass battles, and really see how actual D&D combatants would fare in it. Being able to send your knights and dragons and against the opposing ogres and skeletons and get results in 3 hours that are a close approximation of what you would get if you sat down for 30 hours and played the battle with regular D&D rules is a highly desireable functionality. Obviously it involves changing what you are doing into a wargame at that point, and if people just aren't interested in doing that they won't get much out of it.

But I hadn't really thought of tying it more directly into PC abilities. Often, it seems like certain spells and features can give you extra options, but other classes have little to offer. What does a rogue have to offer as a commander that differs from a fighter?

While it's important to me that the results are similar to playing it out with regular D&D rules, I think I'm going to have to add in another consideration now: making sure different types of characters have unique ways of contributing to the results in both tactical and abstract scales.

I don't think it really needs to be baked into character builds, and it would have to be a pretty focused campaign for that to be a worthwhile expenditure. Instead, I think it will be worth examining the kinds of features that already come with classes and and races and subclasses.

For instance, at the abstract scale having certain features or minimum skill bonuses or feats might let you be better at improving troop morale or leading scouting missions, or constructing siege equipment. I just have to look into all the various sorts of things that could help those types of activities, and make lists that ensure most characters will have one or more things they are particularly good at.

It's much trickier when your are at the tactical level leading units, but in that case it's probably going to be helpful to take some characters' and run some mock battles between units to see how characters with various features can really leverage them in that situation in a way they wouldn't in standard D&D combat situations. I'm optimistic that I can find some cool possibilities.

 

[Krachek]

I think that a party can influence significantly a mass combat using only what DnD do best, small scale dungeon like mission : Spying, kidnapping, rescue, sabotage, …
At battle day, the best thing is to make subset combat against key leader or hero or elite troops, where the party take combat on DnD term.

The only game I know which is close to what you need is the Warhammer setting, and still their battle are done with very small army compared to historical or fantasy battle setting. So upgrading this game to fit ten thousands army and DnD expectation is pretty ambitious.

UA have done some try out for mass battle, it was definitively not satisfying.
The only good point I remember was the idea to simply use to sum of Xp value to evaluate and compare army strength. They were assuming that an organized army would find tactics and strategies to overcome magic, breath weapon, and so on.

 

[Rabulias]

I think the basic problem with D&D mass combat is that the game is not designed with mass combat in mind and players do not build characters towards success in mass combat.

This. Ironic, considering that D&D grew out of a mass combat game, but essentially the crux of the problem. The individual hero was not well represented by Chainmail and its like, so Arneson, Gygax, and others needed to develop new and different rules to do so. That those rules do not lend themselves easily to mass combat is because they were made to cover areas of play not covered by mass combat rules. Not to say it is impossible to write a mass combat system, but it will be hard to incorporate the more "individual-focused" aspects of D&D.