Quick and Dirty D&D Mass Battle Rules Even Non-Gamers Can Understand

One of the hardest things for me about higher-level play in D&D is that, inevitably, we’re going to war. It just makes sense that at some point above level 10, we’re going to get into wars between nations, factions, religions, devils and demons, etc. At that point, either I need to present the war as a bunch of solo, special-forces vignettes – which is an OK approach, but misses something for me – or a bunch of players who never had much interest in wargames are going to have to grasp a unit-level wargaming system.

It’s happened a bunch over the years, and figuring out how to present mass battles in a way D&D players will understand and enjoy is always a struggle. So over the years, I’ve come up with a quick and dirty way to put player characters in charge of units in a way that isn’t too far removed from regular D&D play. We just had one of these sessions, and the players all grokked it easily and said they enjoyed it.

Now, over the years, I’ve played with a lot of rules. It is possible I picked some of this up from other rule sets and forgot where it came from. I am clinging to the shoulders or forgotten giants, as every DM always is. Having said that and denying any solo credit, here’s what we did:

1. Attach the Units to the Players

Rather than have each player control a character and units I put them all together into one turn. Each player has a unit they were commanding, that unit moved with them, then the unit took actions, and then the player took actions. So each player’s turn looked like this:

1. Move with unit
2. Unit takes actions (attacks and bonus actions if they have them)
3. The PC takes their actions
4. End of turn

The unit follows the PC and moves at the same speed, so the player isn’t controlling two units. They cannot move separate to their units – that’s not the game we’re playing here. The PCs are leaders guiding their troops into battle.

Movement mattered because units had to be adjacent to use melee on each other and I gave flanking advantage when a unit had enemies on two sides.

2. Units Are based on Existing Monsters and NPCs

For AC, hit bonus, damage, defenses, etc., I based the unit on existing NPCs and made tweaks for how I wanted them to play. For example, the players had knights, pikemen and archers. I based those on the stat blocks for knights, veterans, and scouts in the Monster Manual. Then I doled out some feats (charger and polearm master [PAM]) to make them play like I wanted.

I did not include multi-attack, but you could depending on how you want them to play. I wanted to try to keep the rolling simple because of the column mechanic below.

The one big guess was HP, and I wish I’d made those a little lower for everyone – maybe just 10X the HP listed in the Monster Manual. It’ll take some tweaking to find the right balance.

Here were the PC’s units. They each got to choose one type of unit to lead.

And here were the enemy units. Most of the enemy units (6) were ghouls, with 2 skeleton units for range and one vampire spawn unit as a bigger threat:

The NPCs did not have leaders, so they acted alone following the same rules. They could not directly attack PCs, but you could change that to fit what you want to do

3. Each Unit Has 5 Columns, and Each Column Makes a Roll

Unlike the PC, the unit is a summary abstraction of many characters. So, when it’s at 100% HP, the unit has 5 columns and each column gets a roll.

When attacking, this means a full-strength unit rolls a d20 for each column to attack (5 rolls at 100% HP), makes one damage roll, and multiplies that damage by the number of hits rolled.

For saving throws, they roll a save for each column and multiply the damage taken by the number of failures. (There’s no half damage on made saves. Damage spells are still totally unit-breaking, though, so half damage isn’t needed.)

Now, as the unit loses HP, it loses columns. For every 20% of the HP lost, they lose one column, and therefore roll 1 fewer dice. So attacks are less effective, but area spells can deal less damage (since there are fewer targets now to hurt).

Also, every time a unit loses a column, it has to make a morale check. This is a charisma or wisdom save by the unit leader (or using the unit save values if no leader) with escalating difficulty:

1. column lost: DC 5
2. columns lost: DC 10
3. columns lost: DC 15
4. columns lost: DC 20
5. columns lost: Unit obliterated

If the morale check fails, the unit immediately dissolves and is removed from the field. If there’s a leader, it stays in play to fight on alone.

The overall effect is that units have less effect on the battle as they lose HP and columns. I did limit the amount of damage a PC’s single attack could do to the average HP of a single monster in the unit, but that could still be significant damage and very seldom was any damage “lost” to that effect.

How Did It Work Out

Overall, this system worked out really well. For starters, the players all understood it, and only 1 of the 7 had wargaming experience. To them, they basically just had a second attack mechanic that went off before their attacks.

The system also didn’t take that long. It was about 2 hours for a fight with theoretically hundreds of characters in play and about 25 units overall. That condensed down to 7 PC initiatives and 4 NPC initiatives (using group initiatives, so all the ghouls, for example, went on the same initiative).

Despite the simplicity and relatively quick play, there was depth and variety in the combat. Fireballs and other area-effect spells were rightly devastating since they could knock out a column or two with one spell. Players had to be cognizant to get advantage and avoid letting the enemies get it against them. The charge, ranged, and PAM effects all gave units different options that the players could use.

This is a quick and dirty explanation of a quick and dirty mass combat solution. Please feel free to reach out with any questions or to clarify anything that’s confusing.

But my overall takeaway here is that mass combat can be a part of D&D without slowing the game to a crawl or causing your players too much cognitive overload.

Do you agree? Have you used mass combat systems before? If so, how did they work out?