World Weaver's Guide to Combat Balance: The Basics
Combat balance in D&D is one of the toughest skills to grapple with, especially as a new DM. However, combat makes up the majority of the game’s core rulebook, and most character abilities lean into combat efficacy. Plus, making cool fights is just really, really fun.
The task of creating combat encounters has different nuances depending on the specific edition, but this blog focuses centrally on 5th edition. As such, my advice here may not be as acutely applicable to other versions of the game. Additionally, because combat balance is such a big aspect of the game, it’s not something I’m going to be able to elaborate on in a single article. This one will contain the basics of combat balance - rules of thumb that are essential to even the smallest of fights so you are alway in control and can pull off engaging, challenging combat.
It’s important to note that crafting good combat encounters isn’t something you can do by just reading some tips. You have to really understand what people mean when they say ‘use minions’ or ‘use tactics’, or you’ll just be making different mistakes.
Finally: no matter how much good advice you consume, D&D is ultimately, at its core, a game of chance. Even the most objectively well-balanced encounters can fly off the handle if the rolls are above or below average on either side. The idea of these tips is to minimize the chances of things other than luck being a factor in fights going poorly.
CR Ratings and their Limitations
Even a cursory glance at the average monster stat block will reveal to you the common features that appear on them. One of those features is a challenge rating, often shortened simply to ‘CR.’ A monster’s CR is meant to be exactly as described - a single number that can tell you about how hard it is to take the thing down. This is a game of chance, so you’re never going to have a perfectly accurate rating. As such, CR ratings are based on the notion that the monster is facing a balanced party of four player characters, with those players having no magic items. So, for example, if a creature is CR 4, that means it would take a 4-player party of level 4 characters to have a balanced fight with the creature.
This system is meant to make it easier for a DM to just pick monsters that fit the level of the party and be assured that they won’t be too difficult or too easy. Problem is - it’s just not possible to do that without throwing a lot of caution to the wind. The first thing you’ll learn when you start making custom encounters: the CR system is flawed enough where relying on it alone will not net you balanced encounters.
You’ll get varying answers from the community, but, in this Weaver’s opinion, the only thing CR is good for is giving you a ballpark representation of when to pull the monster out of your sleeve. You definitely want to keep the number in mind when you’re first formulating encounters, but once you begin to understand how powerful and how weak certain monster abilities are, the system will soon become obsolete.
Monsters have too many variants in abilities to really take an average for what is considered a CR 4 or a CR 10 etc. Not only are the monsters themselves highly varied, but so is the party, which is where we get to the heart of the problem: understanding your party’s power.
Know Thy Enemy
As DMs, you never want to become the antagonist for the party. We are narrators and world weavers, but the neutral sort. While we provide the baddies for the party to fight, we’re not really trying to kill them. We want to present thrilling challenges that have just as much chance at success as at failure. That’s why balance is so important to make combat fun and exciting. This means that even if we’re not setting up the encounter to guarantee death, we do have to consider all the strengths and weaknesses of the party in order to do this. There is a fine line between exploiting weaknesses and playing into strengths.
This is where we’re going to start getting a little technical, but when analyzing your party, considering how much, and how little, of the following the party has:
Healing. Does the party have a character who primarily heals? If not, do they have several people who aren’t focused on healing, but have means to do so?
Control. What kind of abilities does the party have to control the battlefield? This can include enchantment / abjuration spells, crowd control, utility abilities, etc.
Damage. Who’s dealing the most, consistent damage? How much is it at a time? What kind of damage is it (weapon damage, elemental, other?)
Defenses. What is the Armor Class like for the party? Do they have a lot of means to reduce damage?
Equipment. Does the party have a lot of magic items? Magic weapons? Other unique equipment?
If the things in this list are unfamiliar to you or making your head spin, it may be a good idea to look into each element in more detail via your party’s character sheets. In order to make balanced encounters, you need to know the strengths and weaknesses of the party like the back of your hand. However, this does not mean you want to hard counter the party with every single fight - it means knowing what’s going to give them a hard time versus what isn’t based on the make-up of classes and their abilities.
Here’s an example: Vine Blights. These creatures are considered CR ½, but their main attack has the ability to instantly grapple on a hit. Not only that, but the target is considered restrained while grappled (movement is reduced to 0, and other creatures have advantage on attacks against them.) In order to escape, a creature must use their action to beat a DC 12 Athletics check. This isn’t a high DC to beat, but if you find your party is made up mainly of low-strength characters (like spellcasters and rogues) then a Vine Blight is a harder challenge for, say, a barbarian.
This isn’t to say you should avoid monsters that your party is at a disadvantage against, but that you should be aware of and account for it. An enemy, depending on their intelligence, will usually take every advantage they can to win the fight, barring personality dictating certain actions. Sometimes the odds are stacked against the party, but as mentioned, the way to make things fun is to always give the party a chance.
Action Economy
If you’ve pursued forums on combat balance for D&D or even seen other blogs on the topic, you’ve probably seen the words ‘action economy’ thrown around with great import. While it’s further down in this article, it’s honestly one of, if not the most important aspect of combat balance in D&D 5e. While we all love the aesthetic of a band of adventurers squaring off against a single foe, chances are that foe is in for a bad day if it’s only moving once per turn.
Action economy refers to the number of actions being taken by the party versus the amount of actions being taken by the enemy. When you break down D&D combat to it’s bare essentials, it’s largely a battle of attrition. All the abilities the party has are ones that keep them lasting in the fight as long as physically possible, and when a party often consists of at least four people working collaboratively, it leaves monsters with no allies at a disadvantage.
The main takeaway is this: no matter how strong the monster is, it’s almost always at a disadvantage if it’s outnumbered, unless it is ridiculously beyond the skills of the party. Four to five adventurers with weaker attacks that all hit are going to take out a single, big monster with a strong attack with relative ease. This is why you often see a lot of people bemoan how their party managed to take out monsters significantly higher level than them - 9 times out of 10, that monster was alone, and wasn’t played strategically.
We’ll talk about playing strategically later. For now, when just talking about action economy, just throwing in more of the enemy they’re fighting can sometimes do the trick. Want a more challenging fight with goblins with a party of four? Now there’s six goblins. This is a very easy fix at lower levels to make a fight a bit tougher, but remember that this balance change works both ways. If you just haphazardly throw more monsters, it can just flip the balance around and make the party face an unfair fight, so be mindful. A single PC can generally take out more than one monster by themselves, hence why increasing the economy of the monsters can be so important.
Okay - but having the whole party fight a single, big monster is aesthetically pleasing, right? Well, that can be solved with Legendary Actions. For the uninitiated, Legendary Actions are limited, additional moves a monster can take at the start of another creature’s turn in the initiative order. Mechanically speaking, these actions allow your boss monster to have more control over the battlefield even when it’s not their turn. The key is these actions, while effective, is that they are limited. They don’t grant the monster a whole extra turn, just an extra attack, some movement, an area of effect (AOE) ability, etc.
Lair Actions can also help this economy. Many monsters have lairs, dragons being the most obvious. These special actions only occur when the party fights the monster within their lair, and usually affect the environment around them. A single lair action happens per round on Initiative Count 20 (meaning, if you have the list for initiative, you treat a lair action as if it rolled a 20 on Initiative.)
The Battlefield
Changes to the environment can force the party to think on their feet, especially when it’s not a terrain they are strong against. This doesn’t just consider hazards like pools of lava and quicksand, but also points of cover, varying elevations, visibility, difficult terrain, and size. It’s shocking how much more difficult an encounter can become when the party does not have the freedom to move around as much as they’d like. At least, not without a great deal of caution. Many monsters and enemies benefit from the environment being a certain way, and just as many will purposely make their area advantageous to them, especially if they’re setting up some kind of ambush.
Environmental hazards should be a nuisance, but not so much to become frustrating. Effects that completely shut down a player generally make for a very unfun experience. However, making the battlefield something that requires some thought to traverse can add a dynamic to the fight that makes it all the more heart-pounding.
As an example, in my campaign, five party members were fighting two Draegloths in a tiny train car. Because the demons were big, bulky, and are the most dangerous at close quarters, this turned out to be a much tougher fight than I originally balanced for. I didn’t keep in mind that, because the space was so small, the party members with weaker defenses really had nowhere to go to avoid the monsters. None of the player characters died, however, it didn’t make the fight disproportionately tough, which lent itself to more of a frustrating experience then a fun one.
When to Stay Your Hand
If you’re just planning one or two encounters a day, you can get away with making them more difficult, because presumably the party will nearly be at full strength. However, if you’re crafting a dungeon crawl or long travel, you can’t build encounters like the party is going to have all their resources, including spell slots, magic item charges, limited abilities, and supplies. Having too many encounters in a row meant to challenge a full power party can lead to unintended difficulty spikes.
Additionally, even without considering that: it is oftentimes okay to allow the party to have an easy encounter. It can be fun to completely dominate a battle, especially if they have had several tougher ones, and be narratively satisfying.
Conversely, having the party run into something they simply cannot defeat with sheer force can make for a compelling encounter. I would caution from doing this too often, as it can become less fun and intimidating and more frustrating and self-indulgent very quickly. Accidentally waking up the ancient blue dragon they were sneaking around and having to run can be a fantastic encounter, but playing that card more than a few times a campaign can be exhausting. In most cases, too, there simply aren't that many powerful monsters in the world just wandering around. That’s why balancing at higher levels can become harder - you can’t exactly have small armies wandering the road all the time. But, if you demonstrate these dangers early on, it can make the climb to high levels all the more satisfying
Mid-Game Adjustments
We all make mistakes, and sometimes the realization hits you in the middle of an encounter. The ‘oh god this is a harder fight then I intended’ feeling, or the ‘oh jeez it’s round two and my boss is below half health’ feeling are ones you’re bound to feel plenty of times. What to do next is a bit controversial, and highly depends on your style of DMing.
The most common adjustment a DM may make is to health - beefing it up or lowering it based on the need. If the combat is easier than expected for the party, you may gently raise the health of the monster. If it’s too difficult, you may cut their health back. This is very easy to invisibly change, since the party doesn’t usually have access to the total health of the monster, and you don’t have to reveal it to them beyond someone asking how the monster is looking.
This can do the trick on it’s own. However, another (albeit even more controversial) method is ‘fudging’ dice rolls. All your party’s spells are failing because the monster keeps making their save? Whoops, it failed this one. Conversely, the party has landed every save spell and ability? This one is a success.
I cannot express enough that this is not something you want to do often. It’s an ability DMs have, but should not abuse, whether it’s in the players’ favor or not. I can count on two hands, in a two year campaign, when I fudged a save, and it’s when I was still getting the hang of combat balance and frequently made pretty bad mistakes. If you get too comfortable fudging numbers, you’ll start doing it unconsciously, and while your players may never know, it can give you too much control of the results of fights. The spirit of the game lies a lot in the way the dice fall, and you limit your story telling potential by not allowing them to dictate most decisions.
If you do decide to fudge a roll - don’t tell your players when you do. That’s a secret you should keep to yourself till the day you die, in this Weaver’s opinion. If you decide not to use these methods, that’s also perfectly fine, but can put more pressure on you to ensure your encounters are very well thought out beforehand.
Remember to Be Kind to Yourself
As you go through the journey to becoming a better DM, remember not to be too hard on yourself. You’ll make a lot of mistakes, but this is a game, and a complicated one at that, especially when you start getting into deep homebrew. Don’t let anyone make you feel bad for learning, but also be open to learning. Ask your players what they want out of combat. They may want you to ease back, or toughen things up, or keep things the same. Maintaining open communication is always a great way to make sure the players are enjoying themselves. Be willing to admit when you could have done better, and you will find yourself improving at breakneck speed. I believe in you, and you should believe in yourself, because you’re an incredible creative, and nothing can change that.
