World Weaver's Guide to Combat Balance: Boss Battles
It’s been a while since I tackled an article for this blog, largely due to some very pertinent life changes that took priority. That being said, despite my absence for the last three months or so, I’ve found that the engagement here has only grown, and it would be foolish not to keep plotting away when I can at some popular topics in the D&D community (which grow in number every day!)
On the docket today is something I just had a very long conversation with my sister about, who happens to be an excellent DM: boss battles. This well-trodden hike of a topic comes up pretty often in forums, but not in the same way others do. Asking for homebrew ideas for tattoos or special traits is one thing, and another is asking about mechanics and battle assistance. It’s another when you’re, say, planning the final battle of a four year long campaign, or the end boss of an arc, or even just the mini-boss in a mega-dungeon. As I’ve said time and again: balancing combat is one of the most difficult things to learn as a DM, and boss battles often take it to a whole different level.
Boss battles are usually the culmination of something, whether it be the end of a dungeon or the end of a campaign. They cap things off, and test the party on everything they’ve learned so far. It’s no wonder DMs want to get it right. But, just as I’ve talked about in my guide to combat balance, there is no possible way to account for every contingency (of which there are many), so the goal is just to reduce how much of the battle relies purely on luck. As an aside, I do recommend reading that linked article above – it will provide you with a good basis on how I think battles can be approached, and will give you a lot of basic info that will be applicable to regular battles and boss battles alike! Some of the info will be repeated here, too, but bent for the occasion.
So, let’s start with the elephant in the room, shall we?
The Power Creep of 5th Edition Player Characters
A boss for a D&D campaign has many attributes, and I do not want to spare mentioning the emotional part. Yes, there is an emotional aspect, but no, I don’t mean the emotions of the monster being fought. I’m talking about you, the DM. Most DMs can commiserate on the notion that we want the game to be fun, and we also can commiserate on the very real notion that a boss should be a challenge. At least, a little bit of a challenge. Problem is, a common and very fair sentiment of specifically D&D 5e is that, well, the players are pretty powerful. Fifth edition has high magic, strong feats and racial features, and overall really caters to the idea that the player characters are extraordinary individuals who can do incredible things. This is one of my favorite aspects of the game – but I would be lying to you if I said it didn’t make balancing encounters – especially bosses – a challenge to say the least.
Some DMs try to remedy this by just – not balancing encounters and letting fate decide. I personally don’t like this method, but I understand why people go that route. Balancing encounters can be hours of work only for the party wizard to solve the whole thing with fireball. However, I do think that there is a lot more possibility in the way of balancing encounters then people are often willing to explore. It takes time and practice, and trust me, there will be times where it doesn’t work out, but I’d prefer that over the (debatably) more frustrating experience of throwing all caution to the wind and accidentally TPKing the party with six Shadows at level 2.
There’s two extremes that DMs can fall into – snowplowing (i.e. the party just crushing the encounter with zero issue) or long, slogging wars of attrition where neither side is making much progress. “Balancing” is a spectrum between these two extremes. Some folks start with something impossibly hard and work backward, however, I do the opposite.
The best way I have found is, instead of starting with ‘what would be really hard for the party?’ I instead start with ‘what can the party take on easily?’ This means the party starts with the snow plow, then you slowly take that snow plow apart, until they are left with just shovels (or their bare hands). Trying to spike the difficulty harshly can result in, whether intentionally or not, unfair encounters, which ought to be avoided in my opinion. Don’t let frustration get the better of you – trust me, you can make a challenging encounter. You just need to know where to start, and find the wrench to take that snowplow apart.
The Anatomy of a Boss
With that out of the way, let’s start with the basics of the boss themselves. Normally, this is one big baddie, and the party has to defeat them to make progress in whatever situation you’ve placed them in. Let’s go over some basic questions to ask yourself when approaching crafting a boss battle:
Health and Defense. How well does your boss take hits? If they don’t have a lot of health, how do they prevent damage? Can they heal? Can they deflect?
Lair Actions and Legendary Actions. Will the party be fighting this boss in their lair? If so, what actions do they have? What can the boss do at the start of someone else’s turn? Do they have Legendary Resistances? (If you don’t know what these are, check this article out!)
Minions. Will the boss be by themselves, or will they have help? If the latter, how many? Who are they? What are they prioritizing?
Environment: The boss arena – where the whole battle is going to take place. What does it look like? Are there hazards? Are there special defenses the party must destroy or otherwise tamper with first? How does the boss move around the arena? What can be turned against the boss, if anything?
Abilities and Behavior. How does the boss counter the party? How is it susceptible to them? Is it an aggressive attacker, or a calculated tactician?
Alternative Win Conditions. Is the only way to defeat the boss to kill or destroy them? If not, what other solutions can the party utilize?
We’ll break each of these down in a moment, but here’s some less broad information you’ll want to keep in the back of your mind before tackling those questions:
What level is your party? What is their class make-up?
How does your party generally approach combat? (i.e. running straight in, using more tactics, sneaking, heavy buff/debuffs, etc.)
What is going to be the most fun?
Much like I mention in my general combat article, knowing your party well is very advantageous to combat balance. If you’re new and still getting to know the party, just try to have a rough idea in the back of your mind. Chances are you’ve run several battles before your first boss, so having a rough idea is better than none. This will make it easier to have a baseline idea of how to challenge the party, instead of working off of nothing.
Health and Defense
This is a good one to start with because it’s the most flexible part of a boss’s anatomy. I’ll be quick to say the TLDR of health is to play it by ear. When it comes to determining it, I like to use the ballpark method, wherein I don’t have an exact number in mind, so much as a rough range. As the DM, you have the benefit of not having to reveal the exact health to the party, so as a result, if your boss is getting throttled just a little too fast, you can grant them an extra turn by just beefing their health slightly behind the scenes. Granted, this method isn’t for everyone, so if you do want to have a set number, I like to use comparison health too. If you’re making a homebrew boss, check out a monster that’s similar and see what their health is at. For example, maybe you’re running a water serpent – you could give it the same health as, say, a young blue dragon. That being said, I’ve found when I use this method I often need to boost their health a bit, so if you want to use this method, give them an above-average roll for their health.
If you want to get really technical, you could try gathering some data from your party. See what their average damage output is depending on their approach to normal fights, then apply it to the health of your boss. Say you have a high-damage output party with a monk, fighter, and paladin all getting buffed by a bard and cleric – that will naturally result in giving your boss more of a cushion. Conversely, maybe your party has a lower damage output – maybe the party is smaller or they have more defensive classes. In that case, it can be safe to give your boss lower health.
Now, the boss’s defenses beyond health can be a little more specific! The first thing that probably comes to mind is their Armor Class (AC), which can prevent a lot of damage if it’s high enough. However, AC can also be a frustrating counter depending on your party make-up. By that I mean, if you make the AC absurdly high, the entire combat becomes barely chipping away at the monster, since there are very few, if any, abilities that can lower a chonky AC. So, when it comes to AC, try making it just slightly above average, based on your party’s to-hit average. Let’s say you have a party of four level 5 players, and all of them have at least a +7 to hit. This means if an enemy has an AC of 16, the party members only need to roll a 9 or higher on the d20 to hit. The odds are in their favor. If you make their AC 18, then they have to roll an 11 or higher, which slightly moves the scale in your favor. If you made it 25, though, then they would only be able to hit if they rolled an 18 or higher, which heavily skews it to the boss and becomes a slog.
Have a monster that you don’t think makes sense to have a high AC? Don’t worry – there are other defenses you can give them! Let’s do a quick speed-run through some suggestions:
Abjuration Spells, such as Shield and Shield of Faith.
Resistances, especially to common damage types from the party (looking at you, wizard, with your primed fireball.)
Special abilities, such as uncanny dodge or parry, which can mitigate or even stop damage.
Immunities, used sparingly, can really throw a wrench in the party’s usual tactics.
Regeneration or third party healing, like having a pocket healer minion hiding behind a pillar or a personal regeneration.
Temporary hit points, the classic buff to health like a forcefield chipped away before actual damage is taken.
‘Karmic’ abilities, such as Hellish Rebuke, that can damage the party at the same time they damage the boss.
Contrary to popular assumption, you don’t need a lot of defenses to introduce a challenge. A couple well-thought-out ones can do the trick. Throwing too much tankiness can create the opposite problem: a fight that drags out for ages, instead of something that takes a healthy amount of rounds.
Lair Actions and Legendary Actions
Most boss monsters, especially at higher levels, have special abilities that set them apart from just your typical battle. Lair Actions and Legendary Actions are the typical abilities. I won’t get too drawn out with these, but I do want to point out their usefulness. Legendary Actions allow the boss to move on someone else’s turn, which can give them a much needed advantage, such as repositioning, healing, or getting a little extra damage in. Lair Actions, provided they’re applicable, allow a set effect at the same time every round, which isn’t hugely disruptive, but enough to shake up the fight. Remember, too, that especially strong monsters have Legendary Resistances, wherein they can choose to succeed a save they failed. These are very good at buffering rounds if the bard can’t pull off their hypnotic pattern on the boss.
Sometimes, boss monsters I want to use don’t have these: don’t be afraid to add them. For Legendary Actions, remember the 1-1-3 rule (i.e. 1 action for movement, 1 action for attacking, and 3 actions for a special ability) for easier creation. Naturally some monsters have a different delineation of Legendary Actions, but that set up is easiest when you’re new and still learning to balance. For Lair Actions, all of them have saving throws, typically, and they either deal damage or add a status effect that lasts a round. Don’t overthink these – they can be as simple as some stalactites falling or a poison dart shooting out. The saving throws for these abilities tend to be lower, even for powerful monsters, as well.
Minions
Ah, we all new Action Economy – the number of actions the party has versus the monsters – would rear its ugly head eventually. It’s a well-documented dynamic with 5e combat that who controls the most amount of allies has a flat advantage in the game, and thus a lot of balancing guides talk about Action Economy as a major pillar (including me). For bosses, the situation can be a little different then just giving Bilbo the Goblin extra friends in a regular combat. One of the coolest parts of a boss encounter is how one monster can just grabble with a full party of 4 or 5 adventurers! That’s what makes them so cool and scary. However, in practice, this can be hard to pull off, simply because the party has more moves, so the scale spectrum between ‘snowplow’ and ‘unfair’ is a whole lot smaller.
This can be remedied by healthy application of Legendary moves and defenses like above, but that can be difficult for someone new to balancing. Plus, the use of minions can still be very cool and aesthetically pleasing – and have the added bonus of adding some different dynamics to the fight.
In my opinion, minions ought to be significantly weaker than the boss. A necromancer and his army of skeletons, a beholder and their host of summons, a balor and his disgruntled fiend henchmen – the minions are fodder, and they don’t so much pose a gigantic challenge on their own so much as they cushion the boss and deal chip damage, distracting the party from the main goal. The party may be able to dispatch them with one or two attacks, but that is one turn taken away from damaging the boss.
Another nice thing about minions is they can do some grunt work that forces the party to pay some attention to them, like the pocket healer I mentioned, or a burly bodyguard grappling the paladin, or a swarm of bats nipping at and blinding the cleric. Small distractions that don’t utterly debilitate the party can give the boss much needed turns to live, while also spicing up the battlefield. However, try not to be overzealous with minions either – you can very quickly tip the Action Economy scale aggressively in your favor with too many. I like to add one or two extra minions depending on the number of party members. If the party has four people, the boss monster has five or six weak minions.
Environment
A slept-on but no less important dynamic to a boss battle is the arena! Sometimes we focus so much on the boss themselves and their stats that we don’t think about how big a role the space around the boss can play. Lair Actions lightly touch on this, but they only affect the party when they activate. Environmental hazards are passive – they pose a threat simply by existing, such as pools of lava, sheer drops off cliffs, long stretches of slippery ice, or huge bushes of thorns. These hazards can slow movement, damage the party, apply status effects, or even, if particularly reckless, cause their death. The final feature there is why these features are passive. Ideally, you don’t want to have an active feature that can just insta-kill the party, but instead something that’s avoidable but no less important. After all – who’s to say that part of the environment can’t be used against the boss?
Sometimes, the environment can also give the party hidden, or not so hidden, advantages. For example, a young dragon skulking around the ruins of a temple may have trouble finding the sneaky rogue hiding behind the cover of a collapsed, marble pillar. The patches of darkness in a vampire’s castle can give the Way of Shadow monk easy traversal. Carelessly left out barrels of gunpowder may give that fireball wizard a wild idea. For every hazard the party has to face, they can serve a dual purpose!
Abilities and Behavior
This gets more into the personality of your boss, and is naturally very flexible to what you’re going for. Some bosses are going to be easier for the party to fight than others, simply because their abilities cater to a particular fight. For example: a party for clerics and paladins is going to do a lot better against a Mummy Lord than, say, a couple fighters and rogues, because they have a lot of abilities that directly counter the undead. A dragon is going to have a harder time against a party that can readily fly after it than one that’s stuck on the ground, etc. The tricky balance with this is having enough counters to the party to challenge them, but not so many counters that the fight becomes a slog or unfair. Once I had the party fight an ice-based witch character who was immune to cold damage, thinking my cold-based sorcerer in the party had the Transmute Spell metamagic – he did not, so for most of the fight, he could do very little in the way of fighting the witch. To add insult to injury, I didn’t give much indication beforehand that the witch would be cold-based, so he didn’t even get the chance to prepare.
So to avoid my mistake and leaving a party member woefully unprepared, if you plan on supplying your boss with hard counters to the party, or even just massive strengths, try to give them the means to prepare for it. Some things are obvious, like not hitting the red dragon with fire, but some are more obtuse and worth giving small hints. A Cloaker is much easier to kill in bright light – have them get the chance to see said Cloaker shrink away from light before escaping. Organic revelations like this can allow you to give the boss cool abilities without blindsiding your party.
As an avid homebrewer, I tend to make most of my bosses from scratch, but most come from some published template that I adjust to my liking. I love to add some special abilities to common monsters to spice them up, especially when I have a party of experienced players who are very used to the same kinds of monsters (and, as a result, can find it hard not to accidentally metagame with that knowledge.) You don’t have to do this. Instead, you can just find a monster that suits your purposes best, adding spice and flavor by tailoring the behavior of that monster.
Is your stock necromancer the sneaky type? Maybe they’ve set all sorts of traps in their arena and hide in the shadows, using summons until they’re forced out. Perhaps your Mummy Lord boss was once a proud warrior and thus relentlessly keeps the party in melee range by any means necessary. Your Blue Dragon boss is a coward, but also cunning, drawing the party to a damp area to power up their lightning abilities. Your archmage spends the first couple rounds powering themselves up before unleashing a deadly meteor swarm. All this to say, adjusting your boss’s behavior, instead of defaulting to strongest spells and attack-only mentalities, can easily make your fight spicier.
Alternative Win Conditions
One of the things that can make combat more bland in D&D, especially if you run a heavy-combat game, is when the main method of winning the fight is ‘hit it until it dies’. Now, there isn’t necessarily anything wrong with this method – it’s going to be the most common simply because it’s the most straight-forward – but as you get further into levels and better at balancing, this method can become tedious. This is because high-level D&D has a lot of methods for quickly dispatching enemies, even if you balance them well, so even with your best efforts, a boss can simply turn into who can get the biggest number when rolling damage.
This is where alternate win conditions come into play. To use an example from popular media: in the live D&D show Critical Role, as the final battle of their first campaign, the party had to fight Vecna, but fighting a god has complications. Instead of just doing a raw fight, the party had to spend their turns getting pitons stuck in Vecna, then had to recite a passage from an ancient text in order to trap Vecna once again. In this case, hitting Vecna until he ‘died’ actually had very negative consequences, which means the very powerful Vox Machina actually had to stay their hands to prevent doing too much damage to him. This also was suitable for the god status of the boss – one does not simply kill Vecna.
Offering other ways for the party to win the encounter can not only spice up the usual motions, but also give the chance for less combat-focused characters to have a front-facing role in the fight. This also includes prerequisites to the ‘hit it until it dies’ method that can make it a less straight-forward encounter. Here’s a few rapid fire suggestions:
Offering peace is a common way to end fights. If you give enough signs of it being possible, maybe the party can persuade the boss into laying down their arms by offering to talk it out instead. Perhaps your villain of the evening is a desperate person who can be coaxed back to the path of good, or a gray-hatted thug who likes a good deal. Sometimes, this can happen in the middle of combat, if the party plays their cards right.
Turning the minions is an extension of the above. Maybe a dictator of a prison is your boss of the hour, and you rally the prisoners against them. Maybe the goblins in service to their bugbear lord have had enough of him. Maybe you convince the passive partner of the villain to join your side in an effort to shake some sense into their loved one.
Activating a trap is not unlike the Critical Role example. The boss, perhaps, cannot be killed by normal means, and must instead be captured or trapped with some elaborate device. This means the party has to survive the encounter long enough to ensure the trap goes off, and that means approaching the battle in entirely new ways.
Adding prerequisites to the kill can also be an option. The party, for example, has to destroy crystals around the room to remove the boss’s immunity to their attacks, or has to deactivate a forcefield, or has to drag the boss out into the open by smoking them out of hidden hallways.
Escaping, while recommended to use sparingly, can be a really fun chase encounter. Instead of defeating the monster, they have to outrun it by any means necessary.
Naturally, making fights straight-forward is going to be easier on your brain for most fights, which is why alternative win conditions are so nice for bosses. It shakes things up without needing to pick apart a bunch of stats and abilities for the boss themselves. The best part is having the party organically discover these methods in some cases, or making them capable of bypassing them entirely. This gives them agency, and allows them to be creative and not have a single method for winning. Hey, in some cases, they may present an alternative method to you when you didn’t even plan one. Be open to these possibilities! While they won’t always work, allowing them to have a chance in some cases is a great way to build rapport and dynamic encounters with your party.
Remember: Sometimes, Things Won’t Go as Planned
I always remind DMs to be kind to themselves when it comes to planning the game, because frankly, a lot of us have anxiety about keeping things fun. This advice still stands here, but I’m also placing a reminder to loosen up and give yourself permission to not do things right sometimes. There’s no universal ‘right’ way to play the game, of course, but sometimes you spend a long time planning something only for it to not work out how you hoped. That’s okay. You’re not a failure. You’re not a bad DM. You’re a human, and sometimes the dice say ‘no’. Get up, dust yourself off, and work on your next encounter once you’ve taken the breath you need. It’s a game that’s meant to be fun for everyone involved, including you. Roll with the punches and celebrate with your party when they do well, and encourage your party when they’re beaten into the dirt, but survive. Be willing to learn from every encounter you make, and you’ll find yourself more and more comfortable with combat. I know you will be.
