This article was first broadcast in Episode Twenty-Six on 30th May 2018.
Lennon: Ok, so two plus two is four, minus one that’s three
Ryu: What on earth are you doing? Other than quick maths?
Lennon: I’m doing a dry run of a thing for a game. See, I may have painted myself into a corner a bit… or rather into a wide open-field that’s about to be filled with 25,000 creatures on 3 sides, each vying for control of the county
RaeRae: And, let me guess, you’re trying to figure out the damage received during a single round of combat?
Lennon: Combat? I’ve not even gotten as far as rolling initiative!
Ryu: Well, we’ve got a couple of ways that may help you.
Many epic fantasy stories, particularly ones portrayed on the big or small screen, have something in particular that causes people to slot them in the “epic” category: massive battles.
Massive battles are not new to written fantasy. Lord of the Rings always has its Battle of Helm’s Deep and the Pellenor Fields, The Wheel of Time series’ entire last book is an extended battle, and the armies of Westros have been traipsing around murdering each other en masse for four volumes now.
But ever since Peter Jackson and Weta Workshop got together and showed everyone “yes, you can have 40,000 orcs and 12 oliphaunts besieging walled city while 15,000 cavalry charge to the rescue on screen,” visual media have gotten into the act as well, showing people massive amounts of soldiers in mail charging into battle as trebuchet projectiles and, occasionally, dragons fly overhead.
However, the limitations film and literature have overcome are still a challenge for D&D. If you want to play out a battle between massive armies, how do you do it? Even if you’re using a virtual tabletop and can click a button to generate dozens and dozens of creatures rather than having to find that many markers or miniatures, there’s still the issue of having your four to six players take their turns and then figuring out what the literal hundreds of other creatures are doing before they get to act again. Great story material, but your players aren’t likely to stay engaged if they have to wait 45 minutes between turns while you roll hundreds of dice and update 50 creatures’ HP.
Fear not, though. You don’t necessarily have to abandon your dream of having a climactic, army vs army battle as a centerpiece or climax of your campaign. All the methods we’re presenting do involve a certain amount of abstraction, though, so there isn’t a one-size fits all solution. You have to figure out which one works best with your group and with your own style of DMing.
First option: The battle is scenery. Basically, the battle becomes a dungeon crawl, but the dungeon is the trenches, walls, ranks, and soldiers all around the players. In this situation, the characters have a particular goal they’re achieving in the battle, like advancing on a particular enemy position or attacking an enemy commander or something. On the way, they never fight more people or monsters than they would in a regular dungeon, but each encounter is an enemy squad or an archery position rather than a nest of giant spiders.
This method relies a lot on storytelling and painting the picture of the battle to make it feel real. It may help to splash in some environmental effects for flavor, such as having a trebuchet boulder land in the middle of the combat, or at the start of one turn require all the characters to take cover or make saves against a volley of arrows fired at them from one or both sides. It also works a bit better in a campaign where the characters are in a position to take direction and where they have a reason to stick to their ultimate goal. If you describe a cavalry charge in the distance taking out a bunch of soldiers and the players decide they want to dive into that, we’re back to the hundreds of participants problem.
If that happens, or if you’re not confident in your ability to set the scene convincingly or if your players don’t seem to be buying it, you can model the battle in the abstract, except where the players are involved. In this method, you have all of the enemy and friendly soldiers recorded as groups, say 10 groups for each side. You then choose what kind of groups they are: ranged attackers, light infantry, heavy infantry, etc. As the battle goes on, you figure out which groups are engaging and determine behind the screen how the encounters are going.
If you know how you want the battle to go you can predetermine which groups will start losing and how fast. If you want to leave it more up to chance, you can abstract it with die rolls (each group loses d12 troops per turn, for example). The players would choose if and where they want to take part in the battle. At that point, that piece of the battle becomes a regular encounter with each enemy as a creature and each friendly an NPC. Even there you probably want to abstract the combat to save time (like, D20 vs D20 roll, higher wins and does average damage or just outright kills their opponent after x hits rather than attacking vs AC and recording health each time), but the players will see 20 or more creatures around them fighting and can move to assist with real combat actions, while you’re keeping track of the flow of the rest of the battle. So if the players decide they’ve helped enough in one area, you can immediately tell them what other areas of the battle aren’t faring as well with specific information at any time.
Method two involves a lot of bookkeeping for you as a DM and if you’re not comfortable with that it can end up taking a significant amount of time as the players wait for you to resolve the abstracted combats. The third approach to large battles deals with that problem and offers you yet another alternative. Give the players control over one side.
In this method, the players end up controlling multiple NPCs on their “side” while you’re controlling the enemies. This method does little to nothing in reducing the amount of time the battle will take, but it does solve the issue of the players having large swaths of time sitting waiting for you to roll and calculate results; now everyone has a stable of creatures to control and roll for. The downsides here are pretty obvious; apart from doing nothing to reduce the time involved, newer players or those who aren’t comfortable with the game mechanics can easily get overwhelmed trying to control additional creatures. Also, going beyond about 5 or 6 creatures per player will overwhelm even experienced players, so you either have to break it into identical groups or keep the battle limited in size. But if you’ve got a group of players that’s all about rolling dice and modeling combat based on the D&D rules, this is probably the way to go.
There are some tricks that are good rules of thumb in all of these scenarios. First, don’t roll individual initiatives for every creature, even if the players are around; group them up so 3 or 4 are going on the same initiative. You should probably also use the average damage values for regular attacks rather than rolling them each time. Make large groups of enemies all the same type of creature, and avoid using complicated special attacks unless there’s a dramatic reason to do so. Also, unless it’s combat the players are directly involved in, ignore anything that would be an ongoing effect; if a group of soldiers catches on fire, just assume a quarter of them die after three turns or something, don’t bother with all of their saving throws and rolling d6 damage each turn.
On that note, unless area effects hit the players or the people near them, it’s better to assume they’re happening and killing people rather than rolling dozens of dexterity or constitution saves. That can also help with the dramatic tension; probability doesn’t care about good storytelling, so if the enemy wizard is flinging fireballs but the dice are coming up ones all over the place so people are just getting singed and brushing it off, the characters aren’t going to be convinced the wizard is a dangerous target worth wading through enemy squads to eliminate. Similarly, if the enemy archers can’t roll above a 10 to hit, the characters are not going to put a high priority on getting to them and disrupting their fire.
Despite the tricks here, large battles still require a good amount of preparation if you want them to flow smoothly. Unfortunately there’s not really a trick to get around that… unless you can find someone willing to do it for you. However, if you put in the work and figure out which abstraction fits with your group, your characters may be talking about their own battle on the blasted plains for months after you run it.
Lennon: Well those methods are certainly easier than what I was doing, now to just figure out which mobs I want the players to encounter
Ryu: I’ve got a hat for that
Lennon: Ooh, good call
RaeRae: Hat? No! Hey, that’s not a good idea—ok they’ve gone into the vault.