Revised Mass Combat Rules & Combat Unit Template | New Rules for Dungeons & Dragons Fifth Edition

Thinking back on my Mass Combat Rules for Fifth Edition (and reading through the ruleset again), I was thinking up a couple changes I wanted to implement in the design. Well, one thing lead to another I ended up rewriting the whole damn thing.

And I gotta say: it’s way better.


Playtest Content

The material here is presented for playtesting and to spark your imagination. These game mechanics are in draft form, usable in your campaign but not refined by final game design and editing. They aren’t officially part of the game.

Constructive feedback is welcome and appreciated in either comments or social media. If you can give me a valid reason with examples why something is off, 9/10 I’m likely to make changes to the content and credit you for doing so. Otherwise, feedback without anything to back it up gets ignored (or at most a smile emoji like this 🙂 ) Thanks!


Design Notes

One of the most confusing aspects of the ruleset, I feel, were the rules for creating units. With this article, I hope to streamline it a bit more with a template that can work both in mass combat and outside of it.

Here a few things to consider with a mass combat unit:

  • They are effectively swarms.
  • Although a mass combat unit is a swarm, it shouldn’t only be able to attack creatures that share the same space as it.
  • Attacks should work similar to area effects and the opposing unit should have to make a Defense saving throw that works similar to a Dex save but accounts for proficiency bonus and AC. The DC for the unit’s attack roll should be calculated similarly to spell save and feature save DCs.
  • Because there are so many units on the field, tracking individual hit points could be difficult; therefore, I recommend an easier system.
  • All mass combat units should be assumed to have 10 units in them to make math easier.

After coming up with the prototypical creature (the Duergar Unit below), I think I got the rules worked out. I wanted to keep as much intact with Fifth Edition rules this time as I could. There are only a few major changes to it, but the unit would still work well with a normal game of Dungeons & Dragons. Interestingly, a unit working together is far more dangerous than 10 units attacking on their own by virtue of their unit feature and area of effect attacks. I guess “fluff-wise” that makes sense. Trained warriors working as a unit are far more likely to deal severe damage than a bunch of randos attacking individually.

The most important part of this revision is that no math is needed to add individual units into mass combat. So now a fire giant can go toe-to-toe with a unit of drow, and a unit of goblins can jump on top of a single wizard.

Note: I realize that the template I made is pretty complex, so I probably need to just create a lot of the units by hand. Either way, I think these rules are waaay more clean than the last set and fit perfectly into Fifth Edition.


New Rules: Mass Combat

Mass combat uses the following new (simplified) rules:

Commanding Units

As an action, a creature (from here on out referred to as a “leader”) can command one or more friendly units that it can see within 30 feet of it. The unit must be able to hear the leader and share a common language with it. The number of units that a leader can command using this action is equal to half its proficiency bonus.

The unit obeys the leader’s commands as best as it can. It takes its turn on the leader’s initiative, though it doesn’t take an action unless it is commanded to. The unit can be commanded to take the Attack, Cast a Spell, Dash, Disengage, Dodge, Hide, Ready, or Search action.

If the unit is not issued a command, it automatically takes the Dodge action. A unit never requires a command to use its reaction, such as when making an opportunity attack.

Joining a Unit

If a creature shares the same space as a friendly unit at the start of its turn, it can join the unit (requiring no action on its part). While a creature is part of a unit, it cannot be targeted by attacks that affect only one creature or target. If the unit is targeted by an effect that requires it to make a saving throw, the creature makes a separate saving throw, using its own saving throw bonuses.

On the creature’s turn, it can use its bonus action to command the unit that it is a part of (see above). Commanding the unit it is part of does not count towards the total number of units that a leader can command at one time.

Defense Saving Throw

All creatures and units have Defense saving throws. A Defense saving throw is the creature or unit’s Armor Class minus 10. The purpose of the Defense saving throw is to simplify unit attacks.

Advantage

If a creature or unit has advantage on a Defense saving throw that allows it to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Morale Checks

Units and creatures might flee under any of the following circumstances:

  • The unit is surprised.
  • The unit is reduced to half its hit points or fewer for the first time in the battle.
  • The unit has no way to harm the opposing side on its turn.
  • The group’s leader is reduced to 0 hit points.

To determine whether a unit flees, make a DC 10 Wisdom saving throw for the unit (known as a Morale check). You may add the Charisma modifier of the closest friendly leader within 30 feet of the unit. If there is more than one leader within 30 feet, choose the leader with the highest Charisma modifier.

On a failed save, the affected unit flees by the most expeditious route. If escape is impossible, the group surrenders. If a creature or group that surrenders is attacked by its conquerors, the battle might resume, and it’s unlikely that further attempts to flee or surrender will be made.

If the unit is of lawful alignment, it makes its Morale checks with advantage. Similarly, if the unit is of chaotic alignment, it makes its Morale checks with disadvantage.

Rally

A friendly leader within 30 feet of a fleeing unit can use its action to make a DC 10 Charisma (Persuasion or Intimidation) check to stop the unit from fleeing. If the unit is of lawful alignment, this check is made with advantage. And if the unit is of chaotic alignment, this check is made with disadvantage.

Unit Template

The unit template can be applied to any Large, Medium, or Small creature of Intelligence 5 or higher. The following characteristics change or are added to a creature that becomes a unit.

Size. If the creature is Large it becomes a Gargantuan unit of Large creatures of the same type and if the creature is Medium or Small it becomes a Huge unit of Medium or Small creatures of the same type.

Hit Points. The unit’s hit points are 10 times the base creature’s hit point average.

Hit Dice. Units do not have Hit Dice.

Abilities. The unit’s Strength and Constitution scores increase by 8 (to a maximum of 30).

Saving Throws. The unit gains a Defense saving throw equal to its AC minus 10. And the unit gains a morale saving throw equal to its Wisdom saving throw.

Damage Resistances. The unit is resistant to bludgeoning, piercing, and slashing damage.

Condition Immunities. The unit is immune to the grappled and restrained conditions.

Senses. The unit’s passive Perception increases by 5.

Special Trait Modifications. The unit’s special traits are modified to affect the entire group instead of an individual. The easiest way to do this is to take any special traits that don’t deal damage or heal and keep them the same. For traits that deal damage, triple the area of effect for all dimensions.

New Trait: Lawful Units (Creatures of Lawful Alignment Only). The unit makes Morale saving throws with advantage, and other creatures have advantage on Charisma (Persuasion and Intimidation) saving throws to end a broken effect on the unit.

New Trait: Chaotic Units (Creatures of Chaotic Alignment Only). The unit makes Morale saving throws with disadvantage, and other creatures have disadvantage on Charisma (Persuasion and Intimidation) saving throws to end a broken effect on the unit.

New Trait: Unit. The unit can occupy the space of a Medium or smaller creature and vice versa, and the unit can move through any opening large enough for a Medium human. Spells and attacks that affect an area deal triple damage to the unit if the area of effect completely encloses the unit. The unit can’t regain hit points or gain temporary hit points. Targets in a unit’s space have disadvantage on Defense saving throws made against the unit’s attacks.

New Action: Unit Melee Attacks. If the unit has a melee weapon attack that targets one target or creature within reach, remove the attack. It instead gains a special attack that allows it to attack a 10-foot cube at a point within a range equal to the original attack’s reach. Each target in the area must succeed on a Defense saving throw (its AC – 10) or it takes the attack’s full damage on a failed saving throw or half as much damage on a successful one. The attack’s save DC is 8 + the attack’s original modifier + the unit’s proficiency bonus. Multiply the attack’s damage dice by 10. If the unit has half its hit points or fewer, multiply the attack’s damage dice by 5.

New Action: Unit Ranged Attacks. If the unit has a ranged weapon attack that targets one target or creature within reach, remove the attack. It instead gains a special attack that allows it to attack a 10-foot cube at a point within range. Each target in the area must succeed on a Defense saving throw (its AC – 10) or it takes the attack’s full damage on a failed saving throw or half as much damage on a successful one. The attack’s save DC is 8 + the attack’s original modifier + the unit’s proficiency bonus. Multiply the attack’s damage dice by 10. If the unit has half its hit points or fewer, multiply the attack’s damage dice by 5.

New Action: Area of Effect Attacks. If the unit has an attack that affects an area, the area is tripled for all dimensions.


Sample Unit

The following unit uses duergar as the base creature.

duergar-army

Duergar Unit

Huge unit of Medium humanoids (dwarf), lawful evil


Armor Class 16 (scale mail, shields), Defense +6

Hit Points 260

Speed 25 ft.


Abilities Str 24 (+8), Dex 11 (+0), Con 22 (+6), Int 11 (+0), Wis 10 (+0), Cha -9 (-1)


Damage Resistances bludgeoning, piercing, poison, slashing

Condition Immunities grappled, restrained

Senses darkvision 120 ft., passive Perception 15

Languages Dwarvish, Undercommon

Challenge 16 (15,000 XP)


Duergar Resilience. The unit has advantage on saving throws against poison, spells, and illusions, as well as to resist being charmed or paralyzed.

Lawful Unit. The unit makes Morale saving throws with advantage, and other creatures have advantage on Charisma (Persuasion and Intimidation) saving throws to stop the unit from fleeing.

Sunlight Sensitivity. While in sunlight, the unit has disadvantage on Wisdom (Perception) checks that rely on sight. In addition, any creature that must make a Defense saving throw against one of the unit’s attacks or effects does so with advantage.

Unit. The unit can occupy the space of a Medium or smaller creature and vice versa, and the unit can move through any opening large enough for a Medium human. Spells and attacks that affect an area deal triple damage to the unit if the area of effect completely encloses the unit. The unit can’t regain hit points or gain temporary hit points. Targets in a unit’s space have disadvantage on Defense saving throws made against the unit’s attacks.


Unit Actions

Enlarge (Recharges after a Short or long Rest). For 1 minute, the unit magically increases in size, along with anything it is wearing or carrying. While enlarged, the unit is Gargantuan, doubles its damage dice on Strength-based weapon attacks (included in the attacks), and receives advantage to Strength checks and Strength saving throws. If the unit lacks the room to become Gargantuan, it attains the maximum size possible in the space available.

War Picks. The unit targets a unit or creature it can see within 5 feet of it. The target must make a DC 21 Defense saving throw, taking 53 (10d8 + 8) piercing damage on a failed saving throw or half as much damage on a successful one. If the duergar unit is enlarged, the target takes 98 (20d8 + 8) piercing damage on a failed saving throw, or half as much damage on a successful one instead. If the unit has half its hit points or fewer, the target takes half damage from this effect.

Javelins. The unit targets a unit or creature it can see within 5 feet of it. The target must make a DC 21 Defense saving throw, taking 43 (10d6 + 8) piercing damage on a failed saving throw, or half as much damage on a successful one. If the duergar unit is enlarged, the target takes 78 (20d6 + 8) piercing damage on a failed saving throw, of half as much damage on a successful one instead. If the unit has half its hit points or fewer, the target takes half damage from this effect.

Invisibility. The duergar unit magically turns invisible until it attacks, casts a spell, or uses its Enlarge, or until its concentration is broken, up to 1 hour (as if concentrating on a spell). Any equipment the unit wears or carries is invisible with it.


Have a request? Become a patron.

On Patreon, I give out 3-4 PDFs per week, exclusives, and other fun stuff. Plus, you get to make monthly requests.

Learn more about DMDave’s Patreon.

Art by Champions of the Citadel.

2 thoughts on “Revised Mass Combat Rules & Combat Unit Template | New Rules for Dungeons & Dragons Fifth Edition

  1. Interesting take on it. Definitely more streamlined than most takes on the subject. However it is more like “big skirmish rules” than “mass combat”. If units are groups of 10 and we try to give each side 200 or 300 troops, that is still going to be unwieldy in terms of the number of rolls and such per round. Really big scenes with armies thousands or tens of thousands on a side seem totally out of reach. But, I think this might be the perfect scale for acting out critical moments within the larger battle. Like “can the heroes hold the bridge long enough for the reinforcements to arrive?” or “can the strike force infiltrate the enemy camp and stop the ritual without bringing down the wrath of all 10,000 orcs?”

    With regard to morale, having elite guards routing because of surprise plus a junk roll seems off, and total cowards still having a 45-55% chance to avoid routing seems too high. Maybe make the DC vary somehow similar to concentration checks so it is still a single roll and streamlined, but not always based on a 10? Maybe make a unit feature or trait that gives them immunity to routing from surprise?

    A part of me started to think “there’s no way two squads of infantry wipe each other out as fast as two units can”. Then I remembered how fast combat encounters in 5e are supposed to resolve and I realized if anything the resistance might make units last too long. Something I’ll want to test out and see in action before I jump to conclusions.

    Also, you left in a couple references to being “broken” but removed the definition of the state when you edited the post. It is mostly clear but you may want to clean that up.

    Overall looks great on paper and I will definitely have to try this out and see how it works at the table.

    1. I’ve made a few more tweaks. Overall, it’s mostly for tactical level, which is the level Fifth is at. But mostly it saves the trouble of having to run individual units.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.