World Weaver's Guide to Combat: Large Scale Battles in 5th Edition
If you’ve run any games with wars, chances are you have thought about how on earth you’re supposed to run a large scale battle. After all, there’s some breathtaking, epic imagery and scenarios in the clashing of massive armies. D&D gets its origins from war gaming, where the entire premise is to move units and take out your opponent. The intent when making D&D was ‘instead of having several units, what if one person had the power of a unit?’ And thus, we have the game as it is now, with player characters having the powers and capabilities of several ordinary soldiers put together. Combat is turn based through an initiative order to support this play, though it can be notoriously slow. As such, it can be intimidating to try and run an authentic, large scale battle without grinding the entire combat to a snail’s pace.
When you have a lot of turns in the initiative order, it can make battles very confusing and sometimes even frustrating. As the master of the game, you have enough on your plate (I know I do.) Juggling so many aspects of the battle can make it lose the entertaining part of the chaos and instead make it a pain.
This article dives into the mechanical side of massive battles in 5th edition, and suggests some methods to mimic the power and awe of the destruction without hampering your players or dragging out the combat.
Units
Naturally, it would be completely absurd to try and give each soldier their own initiative, but you have to represent them somehow. Instead, you can represent clusters of soldiers with Units. These Units can be treated as ‘swarms’, where they gradually lose power the more health they lose. You can create a swarm by taking the stats of a specific creature and essentially buffing their power.
Let's use the stat block for a guard as an example. You can keep AC, speed(s), languages, proficiencies, and damage resistances the same. For health, use your best judgment. I usually take the average health of the creature (in this case, 11) and multiply it by five. So a unit of soldiers has 55 hit points. If you want to make them particularly tanky, you can multiply it by the number of soldiers conceivably in the unit, which can be anywhere from 8 to 15. Scale it based on the power of the party and how easily you think they should be able to take out the particular unit.
For the unit’s attack, you can do a couple different methods:
Treat the attack as a single target and multiply the number of dice a single member of that unit would do by 4. For example, if a single guard deals 1d6 damage with their spear, the entire unit attacking deals 4d6. This is good for when units are attacking other units, since it’s representory of the clash. Cut the amount of dice in half when the Unit is below half health.
Make the attack require a saving throw instead of having the unit make an attack roll. Same damage option as the one above, but have it do full damage on a failed save and half on a successful one. You can set the ability score for the save based on the nature of the attack, but Dexterity and Strength would be the most common. Set the DC based on the power of each individual in the unit, and you can decrease the initial save when the Unit is below half health. A DC 14 may become a DC 12, for example.
I tend to use both to some capacity. Another feature you can implement is the ‘swarm’ characteristic, which allows a Unit to occupy the same space as another creature. This can simulate being surrounded by soldiers, making it much more difficult to maneuver. Treat Units as difficult terrain when smaller creatures are caught up in them.
A Unit of a creature can be considered one size larger than the creatures that make it up individually. For example, a Unit of medium sized guards would be considered a Large creature, and a Unit of dire wolves would be Huge, etc. When a player targets a Unit, treat it as a single target, much like a swarm. So, if your Fighter PC succeeds in an attack against a Unit, you may describe it as them slicing through two soldiers, seizing a third and throwing them off the escarpment they’re standing on.
Because the nature of Units is that they’re made up of several of one creature, they are often immune to many conditions, such as restrained, paralyzed, charmed, frightened, grappled, and stunned. Use your best judgment when a player wants to target a Unit for one of these effects, as it may not be viable.
Foot soldiers aren’t the only kinds of Units you can conjure up. Here’s a few examples I’ve used in my game for a large scale battle. Note, these units were balanced for a party of level 11 players who had Units of their own on their side:
Cultist Infantry
General Statistics. Speed of 30 ft., 100 hp, AC 16.
Unit Melee Attack. Melee Weapon Attack. Reach 5 ft, + 8 to hit, up to three targets or 1 unit. Hit: 18 (4d6 + 3) slashing damage. If the Unit is below half health, damage is reduced to 2d6.
Unit Ranged Attack. Ranged Weapon Attack. Range 30/150 ft,+ 8 to hit, up to three targets or 1 unit. Hit: 18 (4d6 + 3) piercing damage. If the Unit is below half health, damage is reduced to 2d6.
Hobgoblin Mounts
General Statistics. Speed of 50 ft., 120 hp, AC 16.
Unit Melee Attack. Melee Weapon Attack. Reach 5 ft, + 8 to hit, up to three targets or 1 unit. Hit: 18 (4d6 + 3) piercing damage. If the Unit is below half health, damage is reduced to 2d6.
Charge. The unit charges forward, lances forward. They must move up to their full speed for this maneuver in a straight line. All creatures in their path must make a Dexterity saving throw. On a failure, a creature takes 21 (4d6) piercing damage and is knocked prone, half damage on a successful save and not knocked prone.
Cultist Mages
General Statistics. Speed of 30 ft. 100 hp, AC 15
Unit Magic Attack. Ranged Spell Attack. Reach 60 ft, + 8 to hit, up to three targets or 1 unit. Hit: 24 (5d6) fire, necrotic, cold, OR poison damage. If the Unit is below half health, the damage is reduced to 3d6.
Magic Barrage (Recharge 5-6) The unit casts either Fireball (4th level), Ice Storm, or Vitriolic Sphere at any units or individuals within the radius. The DC for these spells is 15. If the Unit is below half health, the DC is reduced to 13.
Aerial Unit
General Statistics. Flying speed 60 ft., walking speed of 25 ft. AC 15.
Unit Ranged Attack. Ranged Weapon Attack. Reach 30 / 120 ft, + 8 to hit, up to three targets or 1 unit. Hit: 18 (4d6 + 3) piercing damage. If the Unit is below half health, damage is reduced to 2d6.
Spread Darkness. The Vrocks exhale a 60 ft. cone of darkness, shrouding the area and dealing damage. All creatures in the area must make a Wisdom saving throw (DC 16). On a failure, the targets take 4d6 psychic damage, half damage on a successful save. The darkness spread by this attack heavily obscures the path the cone took until the beginning of this Unit’s next turn.
You’ve noticed here that I’ve neglected to write out the ability scores of the Units. That’s because, when determining saving throw bonuses, I simply use the ability scores of the main individual in the unit. So, if a unit is made up of cultists, I’d use the basic Cultist stat block when making saving throws. Like with Swarms, I will usually give a +1 or +2 bonus to the save to account for the increased number of people in the unit, but that bonus disappears when the Unit is below half health. Again, these are all very adjustable features when you construct your own battles. The reduced stat block above requires a lot less reading and will streamline the process.
Units can move alongside the party and act under their own initiative score. If they are being directly commanded by a member of the party, they only follow that party members’ commands. If a command is not issued, they do their best to defend themselves against attack / will take the most direct route to help the forward march. A party member can issue a command with a bonus action, though they must be within 60 ft. of the Unit in order for them to hear. You can give continuous commands, such as ‘attack x unit until they retreat’ or ‘destroy the canon’ etc. If a Unit drops to zero hit points, they immediately begin retreating from battle. They make ‘death saves’ on the way - three successes mean they escape, three failures means all members of the unit die. These sorts of mechanics can be ignored if the party isn’t directly commanding units, but it’s worth mentioning.
Weapons of War
On page 255 of the Dungeon Master’s Guide, you’ll find the stats for weapons of war, such as cannons and trebuchets. Now, these kinds of weapons are not ones you haul into the middle of a battlefield, but instead are used to defend a central point, such as a fortress or city. Not only that, but these weapons take multiple hands to operate. A trebuchet, for example, takes three actions to fire - one to load the ammo, one to tie it down, and one to launch it. Naturally, this makes it impractical for the party to operate, but very practical for a team of NPCs to use.
As explained above, the best way to streamline big combats is to not feel obligated to read out every action. For weapons like this, instead of adding them to the initiative order, have them all fire at Initiative Count 20 (before anyone who rolled below a 20 on initiative, after anyone who rolled above a 20, losing ties.) Alternatively, you can have the weapons fire at the beginning or end of each round.
The weapons tend to be pretty close or completely inside the defense point, so they can be difficult to target for attack. If your party or Units are close enough to be able to attack them, you can treat it as a regular guard unit. After all, attacking the soldiers manning the trebuchet would generally be easier than destroying the weapon itself. That being said, if your party wizard decided to throw a fireball at the nearest weapon, you can smack a number of hit points on the weapon itself and consider it a single target.
The main benefit of siege weapons is they have an insane range. A cannon can fire 500 ft. before it’s considered firing at a long range, for example. The party and any units would have to practically be crawling on top of the weapons before they could do much about them. Conversely, something like a trebuchet is useless against anything too close to it. Avoid using these weapons if a a specific point isn’t being defended, as they add an extra layer to the mix that is avoidable
Gambits
In chess, a gambit is when a player makes a sacrifice (typically a pawn) in order to gain a specific advantage. I somewhat pull from that definition with this mechanic, as well as the video game Fire Emblem: Three Houses. In that game, a tactical role playing game where you move units around a map to take out an enemy force, allows you to assign battalions to certain characters. These battalions can be used to activate a ‘gambit’ - a special move that can either damage the enemy or support an ally. You have to sacrifice the assigned character’s main turn in order to use it, but it can lead to an advantageous effect, such as healing a critical unit or spreading fire in the path of enemies.
Of course there would be no way to elegantly transfer this mechanic exactly to D&D. I lifted the spirit of it to not only give some variety to large battles, but also to give fun rewards to the party for making powerful friends. In regards to the latter, it also allows the party to feel the presence and aid of a favored NPC without adding that NPC directly to the party. This means less balancing on your part to account for the extra hands.
Gambits, thus, are special powers the party can summon for aid during battle. They offer a one round effect that can potentially turn the tide of battle, at the sacrifice of the summoner’s action or even a reaction. Here’s a couple examples of Gambits I used in my game, from particular NPCs the players had befriended:
Vale (falcon feather tossed to the air)
Deja vu. Requires 1 Reaction. Vale dooms a target to feel the same pain once more. Immediately after a target takes damage, they must make a Wisdom saving throw (DC 17.) They take the damage they just took again on a failure, half as much on a successful save. If the creature was subject to a critical hit when this Gambit is called, they have advantage on the save. If the target was subject to multiple damage types, only one of those types occurs again (Vale’s choice.)
Annalanta (falcon feather turned to dust and flung forward)
Temporal Forgiveness. Requires 1 Action. Annalanta reverses damage caused by enemies. She targets up to 3 creatures - battle damage, conditions, and any other statuses that have been inflicted on those creatures in the last round of combat are reversed. She can reverse up to 40 points of damage. This channeling does not automatically remove continuous spell effects inflicted by enemy creatures (such as hold person) who are still concentrating on the spell, however, the creature may immediately reroll the save for the spell (if applicable) to end the effect. If a creature was rendered unconscious during the last round, you simply return them to 1 hit point. This effect cannot bring someone back who was killed instantly (such as by the effects of power word kill.)
Evangeline (hand mirror held to the light)
Moon’s Deadly Dance. Requires 1 Action. Evangeline grants her allies a greater chance of striking their enemies. Up to 5 creatures have advantage on all weapon and spell attacks for the rest of the round. This advantage overcomes disadvantage the creature may normally have.
Gambits can be used once per battle and only once per round, so the party would need to consider the best time to use them. In the examples mentioned above, all the individuals were participating in the battle with them. However, you don’t necessarily need that to be the case. A Gambit could be a boon or blessing given to the party - almost like a one-time-use potion. This means you can use Gambits even when you’re not in a literal war. For example, during a game I was playing in, my DM gave the party a Gambit for saving a young girl from drowning. This Gambit allowed us to reroll a save that one of us failed as a reaction.
The effects I’ve listed are completely homebrew, but you could pull abilities from anything from stat blocks to spell effects to potions. It adds a little pizazz and some very fun sequences depending on the effect of the Gambit.
The Art of War
You don’t have to know the eccentricities of how wars are conducted to make them believable. The most important thing to understand is wars have a lot of moving parts, and there is often some semblance of strategy going into where parts of the army are. It’s not just two floods of soldiers smashing into each other, even if it looks like that on the outside. Now, this isn’t to say you can’t do it that way so much as it will make it harder for you to make it different than any other battle.
At the same time, don’t give yourself the impossible task of describing and detailing every little piece of the puzzle. Your party likely won’t be directly involved in a good majority of it, and even if they’re aware, in the heat of the actual battle it won’t be given notice. If you’re imagining this big battle, take a cookie cutter and slice out the immediate area around the party and work with that. Everything else can be relegated to grand description and maybe the occasional visual event to spur the party to action. Theater of the mind is an irreplaceable friend here, as it just isn’t practical to account for everything. Ironically, scaling down is the best way to preserve the scene. The armies fighting and the chaos all around the party can be treated more as an action set piece than a series of enemies.
How you go about orienting the battle depends on the party’s role in it. Are they leading the army’s charge, or are they a special ops unit weaving through the chaos? Are they using the clashing forces as a distraction to sneak into the citadel or are they directly seeking to defeat the enemy army? If the battleground is merely a backdrop, make it something like a lair, and give it actions of its own on Initiative Count 20 or the beginning of each round. Here’s a quick d6 table with the kind of things I’m talking about:
Battlefield Effects - d6
Three cannonballs slam into the ground, spraying dirt and shaking the earth of three 15 ft. circles. Creatures in the affected areas must succeed a DC X Dexterity saving throw or be knocked prone. The areas are considered difficult terrain until the beginning of the next round.
A trebuchet/scaffolding collapses nearby. Creatures in a 30 ft. line in the direction the structure falls in must succeed a DC X Dexterity saving throw or take 6d6 bludgeoning damage and be knocked prone. On a successful save, take half damage and are not knocked prone.
The wind carries dust and debris in a thick cloud over the battlefield. The immediate area, out to a radius of 30 ft., is heavily obscured until the beginning of the next round.
Spilled oil/gunpowder catches fire nearby, causing an explosion. Place the blast off to the side of the party’s current position. Creatures within 15 ft must make a DC X Constitution saving throw or be deafened until the beginning of the next round.
A barrage of arrows flies toward the party in a 60 ft. cone. Creatures in the area must make a DC X Dexterity saving throw or take 4d6 piercing damage.
No Effect. Roll on this table again at the beginning of the next round.
The table above is for your basic battlefield, but depending on the environment the party is fighting in, you can have all sorts of events. Fighting near an active volcano? Lava flows in a narrow line across the path of the party. The eldritch abomination the party is heading toward getting annoyed? Have them shatter the ground and lift it in the air. You can also preplan certain events to happen at particular points. For example, if the party is advancing on a fortress, you can have traps go off when they get closer and closer to the walls. Or, when a certain number of rounds is reached in initiative, another event triggers.
Organizing the Battle
Now we come to the more technical part - how to run all this without pulling your hair out or slowing everything down. I mentioned above that only worrying about a small area the party is relegated to is the first step in cutting yourself some slack, but here’s some other steps you can take to streamline the process:
Pre-Roll Initiative. This seems like a small thing, but it saves a lot of your time when the battle begins. Before the session where the battle takes place, write or type down all the units participating in the party’s immediate purview and roll their initiatives, adding them to the order immediately. This way, all you have to do is add the party members to the order and you’re off to the races. If you have a digital encounter builder like the one on D&D Beyond, you can roll initiative with a single button.
Use Average Damage. We all like to roll dice, but when you’re juggling a lot of combat, stopping to roll it every time can drag things out, especially when it’s just NPC Units smashing into other NPC Units. Instead, only roll to hit/roll saves, then have them take the average dice roll. Don’t know how to calculate averages? Use this equation: Average = ( ( Max Die Roll + 1 ) / 2 ) * Number of Same-sided Dice, where ‘*’ is multiplying.. So if you wanted to calculate the average of 2d6, it would be ((6 + 1)/2) * 2, which equals 7.
Automate Units. Unless the party is directly controlling Units in battle, you can set them to just be doing one task until it’s complete. For example, a Unit may be charged with destroying a cannon. When it gets to their turn in initiative, you already know what’s happening and just instantly move and roll.
Let Players Know When Their Turn Approaches. Since these battles tend to have a lot going on, it’s easy to get lost. Let the party know who’s ‘on deck’ so they can already be thinking about what they plan to do while you roll for Unit clashes.
Group Similar Units Together in Initiative. Do you have three Units essentially doing the same thing? Have them all move at the same time to declutter your initiative order. You can put the name of the unit then X3 next to it, for example, so you know all three of those units are moving at the same time.
Limit Unit Actions. While Units certainly have plenty of capabilities, it’s still a group of people trying to coordinate around. Try not to juggle a bunch of units doing unique actions, limiting them to attacking, moving, and using objects.
Delegate Allied Unit Rolling. Have a lot of NPC on NPC clashes? You can have a player roll and take limited control of allied Units when there’s a lot of space between turns to take a little off your plate.
Clearly Mark your Units. Whether you’re at a physical table or using a VTT, do yourself a favor and put in the extra prep time to write down the health and names of each unit. I used a piece of paper with the initiative order on it and crossed out the health and wrote it again every time the Unit was damaged, and I put a mark on the name if the Unit was retreating, crossing it out if it was destroyed. You’ll be saving yourself a major headache.
Don’t Make Units Too Bulky. I mentioned that you want to tailor the health of your Units to the level of the party. My party was level 11 when I did the first battle, so most units have over 100 health. But you’ll be surprised how quickly that drains, and that’s a good thing. It’s better to have Units going down a bit too fast then way too slow. Tier the power of your Units with the closeness of the party to their end goal.
Remember to be Flexible and Transparent
When we run chaotic combats, whether it’s a war or a particularly complex boss battle, it’s easy to get overwhelmed and frustrated. Remember to take a breath and be transparent with your party about the load it can be. It’s okay to let them know you may need a little more patience as you work through each round. If you can, give yourself more prep time then usual, and/or run a test combat with the Units you’ve put together. My party had a blast in a ‘war room’ discord channel where they discussed strategy and movements. Conjure excitement with grand descriptions, maybe writing some down preemptively so you have them ready to go with the session. Since you’re likely in it for the long haul, make sure to take breaks between arduous rounds so you’re not burning yourself out. As you ask for patience from your players, they should receive it from you, too.
As I talk about in my combat balance article, too: no matter how well you plan, D&D is ultimately a game of chance. Things will go wrong - and it’s nothing to beat yourself up over. You’ll run an awesome session even if there’s bumps along the way, and construct an incredible battle. I know you will.